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Help to change fuel pump voltage
- Thread starter TheSwishh
- Start date
Open the engine compartment and stand over on the passenger side looking toward the right front corner. There is a large vertical brace about three inches wide against the firewall right near the corner. Mounted near the top of that brace just under the glass is a grey aluminum object about as wide as the brace and not quite as tall. It has fins on it for cooling, and an electrical connection on the left. That's a large resistor for reducing pump voltage. (Caution, this is hot after you've been driving.)
You can pull the connector out of the resistor block, then place a jumper wire across the female connectors inside, leaving the resistor block out of the circuit. For testing you can just use a piece of 14 gauge wire, but if you plan to leave it you should at least get the appropriate spade connectors and make it secure so as not to suddenly lose the pump at a bad time.
This will deliver full car voltage to the pump, but that is not 12v, more like 14.5, which it can handle just fine.
Why do you feel the need to do that?
You can pull the connector out of the resistor block, then place a jumper wire across the female connectors inside, leaving the resistor block out of the circuit. For testing you can just use a piece of 14 gauge wire, but if you plan to leave it you should at least get the appropriate spade connectors and make it secure so as not to suddenly lose the pump at a bad time.
This will deliver full car voltage to the pump, but that is not 12v, more like 14.5, which it can handle just fine.
Why do you feel the need to do that?
Thanks sjs!
The reason I am doing this is to better the fuel pressure on my Bell Turbo system. I tried the MechTech/Haltech way using the stock injectors with the 2 additional injectors but I found that by depending on the two additional injectors at the intake for extra fuel, the furthest pistons were getting starved for fuel. I am going to try and experiment trying "both" Corky Bell's way and MechTech's way. One of the methods that Bell uses is changing the pump volatage so I thought I would give this a try. Any thoughts? Thank you VERY much for taking the time to answer my question!
The reason I am doing this is to better the fuel pressure on my Bell Turbo system. I tried the MechTech/Haltech way using the stock injectors with the 2 additional injectors but I found that by depending on the two additional injectors at the intake for extra fuel, the furthest pistons were getting starved for fuel. I am going to try and experiment trying "both" Corky Bell's way and MechTech's way. One of the methods that Bell uses is changing the pump volatage so I thought I would give this a try. Any thoughts? Thank you VERY much for taking the time to answer my question!
Sorry for the slow follow-up.
I'm surprised that you see a lean condition on the far cylinders, I have not. But, I really haven't checked them since I got a few more serious things sorted out, so perhaps I'll check again. Thanks for the reminder.
Have you checked your fuel pressure under full load? Even after bypassing the resistor block I found that under WOT in higher gears the pressure would start to drop before redline, falling enough to be a big problem. I considered a voltage up-converter to push the stock pump harder (in theory it is rated to 24v) but found that a new high pressure / high volume pump was much cheaper. It was also a bit of a pain to install, but worth it.
Anyway, your plan is the right place to start. Bell's later kits did exactly that but the supplied injector controllers were not much good.
I think we should try to locate as many Bell TT owners as possible and pool our resources, then see if together we can persuade someone to work on a better fuel system. I've got some ideas and may be willing to help fund it if there are enough people interested.
Hey Lud, how about a new Forced Induction section, with sub-sections by manufacturer?
I'm surprised that you see a lean condition on the far cylinders, I have not. But, I really haven't checked them since I got a few more serious things sorted out, so perhaps I'll check again. Thanks for the reminder.
Have you checked your fuel pressure under full load? Even after bypassing the resistor block I found that under WOT in higher gears the pressure would start to drop before redline, falling enough to be a big problem. I considered a voltage up-converter to push the stock pump harder (in theory it is rated to 24v) but found that a new high pressure / high volume pump was much cheaper. It was also a bit of a pain to install, but worth it.
Anyway, your plan is the right place to start. Bell's later kits did exactly that but the supplied injector controllers were not much good.
I think we should try to locate as many Bell TT owners as possible and pool our resources, then see if together we can persuade someone to work on a better fuel system. I've got some ideas and may be willing to help fund it if there are enough people interested.
Hey Lud, how about a new Forced Induction section, with sub-sections by manufacturer?
Hi sjs,
I guess I got information from the right person. I had no idea you had forced induction as well! Are you running soemthing simalar to my addition injectors? If so, I am curios to find out how you went about the stock fuel injectors? I would imagine you upgraded them due to you speaking about your upgraded fuel pump... what injectors did you go with? Are you happy with your results?
Thanks Again, -Brad
I guess I got information from the right person. I had no idea you had forced induction as well! Are you running soemthing simalar to my addition injectors? If so, I am curios to find out how you went about the stock fuel injectors? I would imagine you upgraded them due to you speaking about your upgraded fuel pump... what injectors did you go with? Are you happy with your results?
Thanks Again, -Brad
Well, yes, but not what I had in mind. People interested in keeping up will all things about forced induction would find it simpler if grouped in a separate forum. Of course I realize that's a tradeoff with the fact that you then need to check multiple places if you like to keep up with everything, but on the whole I think it is a large enough specialized category to warrant it's own place. It would make the sharing of related info much simpler IMO and therefore people will do more of it. Just a thought.
Not much time right now so I’ll keep it sort, but we should talk at length. There are a couple other’s with whom I was going to share info as well but I lost the email addresses. : Perhaps they’ll see this and try again?
’93 3.0 with a recent Bell TT that uses the newer turbos (self-contained vacuum line for the actuator rather than lines down from intake) and the twin canister Borla exhaust. It came with two injectors and the Link controller, but the Link interfered with my ECU and no one could resolve it (quickly) so I bought the Greddy Rebic IV and a pair of their 550cc injectors (injectors required different seals to fit). Main injectors are still stock and original. I just solve a major problem by removing the vacuum switch actuated solenoid that cut off the line to the MAP sensor under boost and replaced it with the Basch SmartMap voltage clamp. Meanwhile, I’m interested in more advance solutions because without factoring in at least throttle position I can’t see ever getting it “right” for a daily driver where conditions and how it’s driven are highly variable.
I suspect my stock pump was just too weak to keep up, for whatever reason. Apparently this is not common with similar mileage cars, but it was very clearly so on mine.
sjs,
Thanks for the information on your fuel situation. I feel the same way about factoring in the throttle posisition... there must be a product out there that can make our lives easier. For now I was thinking of changing my Haltech F5 additional injector (2 injectors) to the GReddy Rebic like yours. I was also thinking of upgrading my stock injectors too so I spoke with Mark Johnson and asked him what type of injectors they were using on the BBSC and he stated RC injectors and is going to let me know what flow rate and model number. Hopefully this can help with daily driving. Any thoughts? I also wanted to ask what type of fuel pump did you go with? Does it need a fuel pressure regulator too?
Thanks Again, -Brad
[This message has been edited by TheSwishh (edited 02 August 2002).]
Thanks for the information on your fuel situation. I feel the same way about factoring in the throttle posisition... there must be a product out there that can make our lives easier. For now I was thinking of changing my Haltech F5 additional injector (2 injectors) to the GReddy Rebic like yours. I was also thinking of upgrading my stock injectors too so I spoke with Mark Johnson and asked him what type of injectors they were using on the BBSC and he stated RC injectors and is going to let me know what flow rate and model number. Hopefully this can help with daily driving. Any thoughts? I also wanted to ask what type of fuel pump did you go with? Does it need a fuel pressure regulator too?
Thanks Again, -Brad
[This message has been edited by TheSwishh (edited 02 August 2002).]
Brad,
I wouldn't bother with the Greddy like mine, it's still too limited. In fact, I was hoping the Haltech was better.
I'm also not sure larger primaries are any help unless you reprogram the ECU. In fact it would probably be a bad thing without a good wide band O2 meter to get the A/F ratio correct under various conditions. I think that's my next move, buy a quality portable meter for A/F tuning under real-world conditions. Then I'll rent it to others at a dirt cheap rate.
I wouldn't bother with the Greddy like mine, it's still too limited. In fact, I was hoping the Haltech was better.
I'm also not sure larger primaries are any help unless you reprogram the ECU. In fact it would probably be a bad thing without a good wide band O2 meter to get the A/F ratio correct under various conditions. I think that's my next move, buy a quality portable meter for A/F tuning under real-world conditions. Then I'll rent it to others at a dirt cheap rate.
Hi Everyone,
I also have a recent Bell TT Kit. I got it Feb 2002. It came with the Link Injector Controller and when I first installed it, it would cause my TACH. to drop to 0. I put a Diode in line with the TACH signal coming from the ECU to the Link Controller Box and my TACH works (sort of). When under boost and the Link Controller is on full spray, my TACH. drops to 0 and have to rely on my HKS CAMP system display which comes off the same TACH. signal of the ECU & Link Controller (its still a mystery). I've learned something new from SJS's postings about the further injectors not benefitting from the additional injectors. I've been considering either bypassing the fuel pump resistor, upgrading the fuel pump, but Im leaning heavily towards getting upgraded RC Engineering Injectors (370's) that I found out about from another posting (General NSX Discussion / Turbo kit from NSX Modified ). Hopefully those will work so I can get rid of the piece of crap Link Injector Controller box. What do you guys think?
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I also have a recent Bell TT Kit. I got it Feb 2002. It came with the Link Injector Controller and when I first installed it, it would cause my TACH. to drop to 0. I put a Diode in line with the TACH signal coming from the ECU to the Link Controller Box and my TACH works (sort of). When under boost and the Link Controller is on full spray, my TACH. drops to 0 and have to rely on my HKS CAMP system display which comes off the same TACH. signal of the ECU & Link Controller (its still a mystery). I've learned something new from SJS's postings about the further injectors not benefitting from the additional injectors. I've been considering either bypassing the fuel pump resistor, upgrading the fuel pump, but Im leaning heavily towards getting upgraded RC Engineering Injectors (370's) that I found out about from another posting (General NSX Discussion / Turbo kit from NSX Modified ). Hopefully those will work so I can get rid of the piece of crap Link Injector Controller box. What do you guys think?
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Hello,
The first thing I would do is get rid of that "link" control! I swithched to the Haltech and others have switched to the GReddy Rebic. I think you are on the right track with upgrading the injectors and 370cc sounds OK. -What boost levels are you running? The fuel pump upgrade is the way to go and is what I plan on doing when I get my motor back in. Bottom line is that I would still use the additional injectors. Just find a way to use them better.
[This message has been edited by TheSwishh (edited 03 August 2002).]
The first thing I would do is get rid of that "link" control! I swithched to the Haltech and others have switched to the GReddy Rebic. I think you are on the right track with upgrading the injectors and 370cc sounds OK. -What boost levels are you running? The fuel pump upgrade is the way to go and is what I plan on doing when I get my motor back in. Bottom line is that I would still use the additional injectors. Just find a way to use them better.
[This message has been edited by TheSwishh (edited 03 August 2002).]
TheSwishh,
Where can I get the Haltech and does it ground out the signal to your TACH.? I'm going to get the RC Engineering 370cc Injectors and still use the additional injectors that came with my BELLTT kit. I just need a Injector Controller that will work properly with my NSX's TACH. I currently run it at 6psi and had the A/F ratio set up to near factory specifications. It runs really strong but I think I can get some more out of it (safely) with the right fuel set up (which I should have gotten in the first place providing the money it cost me to buy the kit)
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Where can I get the Haltech and does it ground out the signal to your TACH.? I'm going to get the RC Engineering 370cc Injectors and still use the additional injectors that came with my BELLTT kit. I just need a Injector Controller that will work properly with my NSX's TACH. I currently run it at 6psi and had the A/F ratio set up to near factory specifications. It runs really strong but I think I can get some more out of it (safely) with the right fuel set up (which I should have gotten in the first place providing the money it cost me to buy the kit)
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NSX Twin Turbo,
I had the same problem with the Link, and I tried the same fix but without much success. Not only did it still kill the tach at high RPM & boost, it also quit signaling the injectors at that same time. I tried a great variety of diodes and found that three (of values I've forgotten) in series plus a resistor (also forgotten) gave me the best results but still very quirky. I even spoke with a guy at the North American Link distributor. He was very helpful (sounding) and anxious to get his techs on it, then he just stopped responding to calls and email. I pitched it in a box for a future Miata or 510 project and bought the Greddy (plus injectors). I'm still not very pleased, but it was a big improvement.
As I mentioned above, I'm not inclined to recommend larger main injectors unless you have a way to control them. Unless you change the stock ECU maps you may be way rich at part throttle. I suppose that the stock 02 sensors will keep things right to a point, but they are only for idle and cruising. Once they are out of the picture your ECU will be pushing the larger injectors as if they were smaller ones, not knowing any better. Tuning with a wideband meter for a variety of throttle positions will be critical, before you wash down the cylinders with too much fuel.
BTW, did your kit still come with the little vacuum actuated micro switch to trigger a solenoid cutting off the line to the MAP sensor under boost? Under hard up-shifts mine would trap a bit of vacuum in the line when it closed, which meant that the main injectors didn’t pump at full capacity and I’d have a sever lean condition. Because it was only on rapid shifts it wouldn’t do it on the dyno, just in real-world conditions. Having read a number of horror stories about the system I am tempted to believe that others have experienced the same thing but never accurately diagnosed the problem. The solution of course is to trick the MAP sensor electronically rather than mechanically, as Basch and Comptech have done.
[This message has been edited by sjs (edited 03 August 2002).]
I had the same problem with the Link, and I tried the same fix but without much success. Not only did it still kill the tach at high RPM & boost, it also quit signaling the injectors at that same time. I tried a great variety of diodes and found that three (of values I've forgotten) in series plus a resistor (also forgotten) gave me the best results but still very quirky. I even spoke with a guy at the North American Link distributor. He was very helpful (sounding) and anxious to get his techs on it, then he just stopped responding to calls and email. I pitched it in a box for a future Miata or 510 project and bought the Greddy (plus injectors). I'm still not very pleased, but it was a big improvement.
As I mentioned above, I'm not inclined to recommend larger main injectors unless you have a way to control them. Unless you change the stock ECU maps you may be way rich at part throttle. I suppose that the stock 02 sensors will keep things right to a point, but they are only for idle and cruising. Once they are out of the picture your ECU will be pushing the larger injectors as if they were smaller ones, not knowing any better. Tuning with a wideband meter for a variety of throttle positions will be critical, before you wash down the cylinders with too much fuel.
BTW, did your kit still come with the little vacuum actuated micro switch to trigger a solenoid cutting off the line to the MAP sensor under boost? Under hard up-shifts mine would trap a bit of vacuum in the line when it closed, which meant that the main injectors didn’t pump at full capacity and I’d have a sever lean condition. Because it was only on rapid shifts it wouldn’t do it on the dyno, just in real-world conditions. Having read a number of horror stories about the system I am tempted to believe that others have experienced the same thing but never accurately diagnosed the problem. The solution of course is to trick the MAP sensor electronically rather than mechanically, as Basch and Comptech have done.
[This message has been edited by sjs (edited 03 August 2002).]
sjs,
I forgot to ask you about this... your statement "the little vacuum actuated micro switch to trigger a solenoid cutting off the line to the MAP sensor under boost." How did you find this out? All I have is a little plastic filter looking thing that connects between my vac/map line. Is this what you had? I am interested in the Basch SmartMap voltage clamp if you can explain what it does. This might be why I was having my lean condition and snapped two of my pistons???
I forgot to ask you about this... your statement "the little vacuum actuated micro switch to trigger a solenoid cutting off the line to the MAP sensor under boost." How did you find this out? All I have is a little plastic filter looking thing that connects between my vac/map line. Is this what you had? I am interested in the Basch SmartMap voltage clamp if you can explain what it does. This might be why I was having my lean condition and snapped two of my pistons???
SJS,
I didnt use the little vacuum actuated micro switch to trigger a solenoid cut off to the MAP Sensor line. It was never put my BELL TT kit and I called Corkey Bell with this problem. He solve that problem by charging me another $100.00 to send me one even though it was Bell's mistake by not putting one in my kit in the first place. I was very unhappy with that situation. Plus it took 2 weeks to get it and my kit was completely installed with that exception. While waiting, my friend told me about the "Missing Link" Mechanical Map Sensor Blocker from Overboost.com. I got it in 3 days and was on the road. On General NSX Discussion / Turbo kit from NSX Modified those guys with the NSX Modified single turbo kit were discussing their fuel setups and I believe that's the way we need to go. I feel that once we get our fuel setup right we will start to have a lot more fun with our NSX's and have a lot less worries.
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I didnt use the little vacuum actuated micro switch to trigger a solenoid cut off to the MAP Sensor line. It was never put my BELL TT kit and I called Corkey Bell with this problem. He solve that problem by charging me another $100.00 to send me one even though it was Bell's mistake by not putting one in my kit in the first place. I was very unhappy with that situation. Plus it took 2 weeks to get it and my kit was completely installed with that exception. While waiting, my friend told me about the "Missing Link" Mechanical Map Sensor Blocker from Overboost.com. I got it in 3 days and was on the road. On General NSX Discussion / Turbo kit from NSX Modified those guys with the NSX Modified single turbo kit were discussing their fuel setups and I believe that's the way we need to go. I feel that once we get our fuel setup right we will start to have a lot more fun with our NSX's and have a lot less worries.
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My two cents on fueling..
Listen to SJS when he says not to upgrade your main injectors unless you also add some sort of control mechanism for them.
I've been running the Rebic 4 w/ 550cc injectors on my setup for a while now, and at least for me they work great. The car runs well both part and full throttle, no hesitations or lulls. (I've offered to talk to SJS before about this but he doesn't answer my emails).
As far as fuel pump voltage goes, I am running a Kenne Bell "Boost a Pump". Unlike the mod described earlier of converting your system to 14 volts full-time (which has the unwanted side effect of running the extra pressure & heating up the fuel when you're at idle & otherwise cruising around town), this system only comes on when you're in boost. When it comes on, it will raise the voltage by a certain percentage, which you can adjust via a knob.
I think I have my voltage set for around 17 volts once I'm into boost.
I also have a 6:1 rising-rate FPR to add in a little fuel at the main injectors once I'm into boost (and to compensate for the rising pressure in the cylinders)
As far as the valve setup to protect the MAP.. One of these days I've got to order the Basch SmartMapper and limit things electronically.. For now I'm using several check valves. It's worked out pretty well, the extra valves help bleed off any trapped pressure. Before that, I would hit a hesitation from time to time.
I'm seeing more and more people on the net with Twin Turbo NSX's. Very cool. I second SJS's request to have an NSX Twin Turbo forum so we can all gather and exchange info and tweaks.
Best,
Marc
Listen to SJS when he says not to upgrade your main injectors unless you also add some sort of control mechanism for them.
I've been running the Rebic 4 w/ 550cc injectors on my setup for a while now, and at least for me they work great. The car runs well both part and full throttle, no hesitations or lulls. (I've offered to talk to SJS before about this but he doesn't answer my emails).
As far as fuel pump voltage goes, I am running a Kenne Bell "Boost a Pump". Unlike the mod described earlier of converting your system to 14 volts full-time (which has the unwanted side effect of running the extra pressure & heating up the fuel when you're at idle & otherwise cruising around town), this system only comes on when you're in boost. When it comes on, it will raise the voltage by a certain percentage, which you can adjust via a knob.
I think I have my voltage set for around 17 volts once I'm into boost.
I also have a 6:1 rising-rate FPR to add in a little fuel at the main injectors once I'm into boost (and to compensate for the rising pressure in the cylinders)
As far as the valve setup to protect the MAP.. One of these days I've got to order the Basch SmartMapper and limit things electronically.. For now I'm using several check valves. It's worked out pretty well, the extra valves help bleed off any trapped pressure. Before that, I would hit a hesitation from time to time.
I'm seeing more and more people on the net with Twin Turbo NSX's. Very cool. I second SJS's request to have an NSX Twin Turbo forum so we can all gather and exchange info and tweaks.
Best,
Marc
Marc, sorry! So that was you. Nothing personal, I just have busy spells at times and at one point I lost a bunch of mail I hadn't pulled down to my PC. (Even with plenty of room to spare, AT&T dumps email over 30 days. Aaarrrgh!!) Yours is probably one that I lost track of.
Anyway, I am quite anxious to discuss TT issues. Perhaps we should start a long thread since we can't get our own space. We could just do it by email but then other's that we don't know of won't find us.
Mark,
Thanks for the 2 cents... they are worth way more than that! I checked into the Kenne Bell Boost a Pump today and they have two different models... a 20amp and 40amp unit. Which one do you have? If this works like you say, its going to be awesome and help me out BIGTIME!
Thanks! -Brad
Thanks for the 2 cents... they are worth way more than that! I checked into the Kenne Bell Boost a Pump today and they have two different models... a 20amp and 40amp unit. Which one do you have? If this works like you say, its going to be awesome and help me out BIGTIME!
Thanks! -Brad
Nor mine!
Originally posted by DutchBlackNsx:
Nor mine!
C'mon guys, give me a break! I think I just got the one from you (DutchBlackNsx) in the past day or two and I'm swamped. These things take some thought and time.
Please don't give up on me.
Originally posted by sjs:
Please don't give up on me.
I won't
Here in bay area, Dan Tobie (tunapie) has modified Bell TT. He uses Greddy E-manage and bigger injectors. As well as water/air intercooler. Try email him at [email protected] as he only check the board occasionally.
SJS - Ok, drop me a line when you get a chance and let's chat!
I still think it's best we get a message forum going somewhere.. There are many topics to discuss & the knowledge needs a permanent place to stay.
Brad: I went with the 20amp/cheaper version. If you do that, you will be able to increase the voltage to 17 volts max. You may want to consider the more powerful version if you want to run higher voltage (doesn't the Comptech setup run 20+?). Just remember, it's really only going to help insure that the fuel is "available" but you still need to have the right components/tuning to actually use/meter that fuel.
While I may be running a little rich (I'd rather be safe than sorry), it was very surprising to me just how much of the 550's & the rest of my fuel system I was making use of.
Andrie/all - I spoke with Dan Tobie the other day. Nice guy. I'm sure he can speak for himself
but as a heads-up his car is in the process of being tuned so right now he's not running more than 3-4 psi. I'm looking forward to finding out how much his air/water I/C's help. I only wish he could have gotten the system dialed in and tuned with the stock Bell I/C's to establish a baseline so we'd know the impact the air/water I/C made.
On a different note... I threw some 100 octane gas in the tank last night (in about a 3:2 ratio with 91 octane). So far I've noticed no difference, but I need to drive the car longer & see if the ECU makes any adjustments. If the power doesn't increase any, I guess that means I'm either running overly rich already, or that I'm running well & the ECU hasn't felt the need to retard my timing at all due to the forced induction.
Marc
I still think it's best we get a message forum going somewhere.. There are many topics to discuss & the knowledge needs a permanent place to stay.
Brad: I went with the 20amp/cheaper version. If you do that, you will be able to increase the voltage to 17 volts max. You may want to consider the more powerful version if you want to run higher voltage (doesn't the Comptech setup run 20+?). Just remember, it's really only going to help insure that the fuel is "available" but you still need to have the right components/tuning to actually use/meter that fuel.
While I may be running a little rich (I'd rather be safe than sorry), it was very surprising to me just how much of the 550's & the rest of my fuel system I was making use of.
Andrie/all - I spoke with Dan Tobie the other day. Nice guy. I'm sure he can speak for himself
On a different note... I threw some 100 octane gas in the tank last night (in about a 3:2 ratio with 91 octane). So far I've noticed no difference, but I need to drive the car longer & see if the ECU makes any adjustments. If the power doesn't increase any, I guess that means I'm either running overly rich already, or that I'm running well & the ECU hasn't felt the need to retard my timing at all due to the forced induction.
Marc
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