In the 1997 manual it is on page 11-129
. Same procedure.I am not 100% sure this will cure either of the two issues, but it worked recently for me.
Regards,
LarryB
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Please Help With Engine Stall/Idle Problem
- Thread starter TypicalNSX
- Start date
In the 1997 manual it is on page 11-129
. Same procedure.I am not 100% sure this will cure either of the two issues, but it worked recently for me.
Regards,
LarryB
- Joined
- 2 June 2006
- Messages
- 769
I do caution anyone not mechanically inclined to not RUSH into doing even the simplest "repairs". If you detach your throttlebody, replace with new gasket after cleaning gasket surfaces and use BRAKE CLEANER to clean the passages and the throttle plate area(you will see a ring around the edge of grime) , then it should solve your issues. You should not have to adjust idle speed setting at all unless modified. Just my two cents.
3M makes a great product that utilizes a pressurized can that hooks up to your vacuum line and you let car run at idle until can is empty.
3M makes a great product that utilizes a pressurized can that hooks up to your vacuum line and you let car run at idle until can is empty.
before getting the stalling problem fixed, the car ended up breaking down again on the freeway. since then i've sent it back to the person that built the engine: the renowned factor x engineering in las vegas. currently he is unavailable for status.
he said he did a compression test and everything turned out ok in that department so i'm thinking the cause for the breakdown is something mechanical in the head somewhere which could be the cause for the stalling. while the car was breaking down, i was hearing a large clank! clank! sound so it could be do to valves or something since the bottom end seemed ok.
i've tried a few times to clean the throttle body inside and out, also replaced the throttle body from a friends car and still no solution. my guess is that after you've cleaned the throttle really good and there's still a problem, you may have a serious issue.
will let you know how the car comes out.
he said he did a compression test and everything turned out ok in that department so i'm thinking the cause for the breakdown is something mechanical in the head somewhere which could be the cause for the stalling. while the car was breaking down, i was hearing a large clank! clank! sound so it could be do to valves or something since the bottom end seemed ok.
i've tried a few times to clean the throttle body inside and out, also replaced the throttle body from a friends car and still no solution. my guess is that after you've cleaned the throttle really good and there's still a problem, you may have a serious issue.
will let you know how the car comes out.
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In the 1997 manual it is on page 11-129
I am not 100% sure this will cure either of the two issues, but it worked recently for me.
Regards,
LarryB
I can't emphasize more what Larry is saying,our 95-96 cars have some sort of voodoo ecu idle reset procedure that even my dealership could'nt figure out,but an hour or so with Larry B and my years of idle dip/stall are over:biggrin:
Forget EVERYTHING I posted on this thread, If the motor is not stock, all my comments are useless. I would tend to think this has nothing to do with the throttle body or idle system. I built motor adds a new dimension to this I was not aware of.
Good Luck,
Regards,
LarryB
the motor was built to stock specifications. actually, when i first got the motor back, it was running fine and when it started stalling, i cleaned the throttle body and it stopped stalling for a long time. but now it does it and i'm thinking it is a different problem. i dont think being built changed anything because it did run fine like that for a while, i think the car just has lots of problems because its old. hopefully i'll have a solution.
In the 1997 manual it is on page 11-129
I am not 100% sure this will cure either of the two issues, but it worked recently for me.
Regards,
LarryB
Thanks Larry. I looked up the page, and it is for testing/adjusting idle RPM. The procedure requires a tachometer, which I don't currently have. However, my issue is not with steady state idle speed. From the dash tach,, it seems to be at 600-800 RPM. The problem is when that when engine comes down from higher RPMs, the RPMs keep dropping to almost nil, and then come back up again to the correct RPM. So far, my engine has never stalled doing this. It shudders though. My engine is completely stock and original.
From the other posts here, it sounds like what I need to do is clean the throttle body. Do you concur? If so, can this be done simply using the 3M product mentioned vs. removing the TB and dissassembling?
Kevin T.
Swift,
What is the 3M product? Are you suggesting that it can clean the throttle body without removing it from the engine? And, just curious, why brake cleaner? The service manual says to use carburetor cleaner (page 11-151).
PS - My son is an ASE Master Technician. Hopefully, he will bail me out of any trouble I get myself into! This is DIY, after all!
Thanks,
Kevin T.
Kevin,
Assuming your car is stock, you should clear out the idle passage first. I use any good carb/choke cleaner, but there also is "Throttle Body Cleaner" availble. I have been told that carb cleaner could react funny to plastic parts on the throttle body, but also have been told this is isolated to Ford cars. I have NEVER had an ussie using carb cleaner on an NSX throttle body, and I have cleaned many.
BTW, you have a tach on the dash.
I mentioned the procedure above, since as DocJohn mentioned, his car would not idle for years, he brought it to me and I performed this procedure. The car is fine now, idles as it should. I have to give credit to Jeff at SoS, since these guys have been doing the big bore throttle bodies, he has used this to get cars reset with the big bore OBDII throttle bodies.
Regards,
LarryB
Assuming your car is stock, you should clear out the idle passage first. I use any good carb/choke cleaner, but there also is "Throttle Body Cleaner" availble. I have been told that carb cleaner could react funny to plastic parts on the throttle body, but also have been told this is isolated to Ford cars. I have NEVER had an ussie using carb cleaner on an NSX throttle body, and I have cleaned many.
BTW, you have a tach on the dash
.I mentioned the procedure above, since as DocJohn mentioned, his car would not idle for years, he brought it to me and I performed this procedure. The car is fine now, idles as it should. I have to give credit to Jeff at SoS, since these guys have been doing the big bore throttle bodies, he has used this to get cars reset with the big bore OBDII throttle bodies.
Regards,
LarryB
Check with Larry B on this but when my Preludes, (apples and oranges) start to lose their high speed idle sensors, (I have had several fail as I have four preludes, two with over 310,000 and two with over 250,000) it does the exact same thing as your NSX, idle reduces to below standard idle to nearly nil and then back to normal for awhile until it fails all the way and then idle raises and lowers randomly.
It is in your idle circut.
Just a thought.
Don't replace the crankshaft if it only needs an air filter.
Cheers
It is in your idle circut.
Just a thought.
Don't replace the crankshaft if it only needs an air filter.
Cheers
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Hello all,
I thought I would report back. Per some of the suggestions here, I cleaned the throttle body using 3M Throttle Plate and Carb Cleaner. Really, I only cleaned the throttle plate and the air-side of the body, since I cleaned it in place. Basically, I removed the baffled hose between the air-cleaner and TB, placed a rag under the TB to catch run-off, and sprayed the heck out of it! Did the best I could to manipulate the throttle plate while cleaning and used a rag-covered screwdriver to get as far back as I could and to remove the residue/grime. Getting to the top and back of the throttle plate was pretty much impossible without taking the whole TB off the car. So, I hoped for the best.
Of course, it started to rain as soon as finished! I finally got it out to test today, and... Perfect! My idle problem is completely gone. Rock steady. Thanks all. Total cost of repair: $4.
-Kevin T.
I thought I would report back. Per some of the suggestions here, I cleaned the throttle body using 3M Throttle Plate and Carb Cleaner. Really, I only cleaned the throttle plate and the air-side of the body, since I cleaned it in place. Basically, I removed the baffled hose between the air-cleaner and TB, placed a rag under the TB to catch run-off, and sprayed the heck out of it! Did the best I could to manipulate the throttle plate while cleaning and used a rag-covered screwdriver to get as far back as I could and to remove the residue/grime. Getting to the top and back of the throttle plate was pretty much impossible without taking the whole TB off the car. So, I hoped for the best.
Of course, it started to rain as soon as finished! I finally got it out to test today, and... Perfect! My idle problem is completely gone. Rock steady. Thanks all. Total cost of repair: $4.
-Kevin T.
Did anyone every find the answer to this problem?
Rather than go through the chain of post again I have the same issue: 1) Car runs find at idle, 2) Bring the car up to 3000 / 3500 RPM or do one quick push of the accelerator and let off 3) the cars rpms drop to below 1K and it oscillates up and down like it has not brain and sometimes eventually dies. There is no check engine light.
I just replace the PCV valve and will have a shop hook up the computer to diagnose. I’m going to try the carb cleaner to clean out the throttle body area. Then possibly spend more money and replace the EGR ?? ..?? – can anyone tell me where I can get one for less than $300.00
I’d also like to find some answers to this issue since it seams many people have the problem but yet no answers. Thank you for advice.
Rather than go through the chain of post again I have the same issue: 1) Car runs find at idle, 2) Bring the car up to 3000 / 3500 RPM or do one quick push of the accelerator and let off 3) the cars rpms drop to below 1K and it oscillates up and down like it has not brain and sometimes eventually dies. There is no check engine light.
I just replace the PCV valve and will have a shop hook up the computer to diagnose. I’m going to try the carb cleaner to clean out the throttle body area. Then possibly spend more money and replace the EGR ?? ..?? – can anyone tell me where I can get one for less than $300.00
I’d also like to find some answers to this issue since it seams many people have the problem but yet no answers. Thank you for advice.
Ktbia - I'm about to try the throttle body clean job that you did as My idle moves up and down after the car comes off High RPM and sometimes it has stalled on me. The Idle is great once it gets there but from high RPM down to idle when let off the gas, it acts like it has no brain. Any advice before I do this job? Can I just move the TB back and forth and just spray Carb Clean all around? Do I let it drip dry or do I wipe things down before I restart the car? THank You for your advice. 1992 NSX 3.0 with 147K on it.
I just replaced PCV and don't really want to spend $300 on EGR
http://www.nsxprime.com/forums/showthread.php?p=1110050#post1110050
I just replaced PCV and don't really want to spend $300 on EGR
http://www.nsxprime.com/forums/showthread.php?p=1110050#post1110050
EGR problems will throw a CEL.
There is tons of info on idle problems and most can be solved with proper cleaning of the throttle body.
http://www.nsxprime.com/forums/showthread.php?t=56821&highlight=throttle+body+cleaning+larry
There is tons of info on idle problems and most can be solved with proper cleaning of the throttle body.
http://www.nsxprime.com/forums/showthread.php?t=56821&highlight=throttle+body+cleaning+larry
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I sent a reply to your PM, but I will also post it here and add some more specifics as to what I did.
I probably did not do the cleaning in the most thorough, correct way in that I did not first remove the air cleaner before cleaning the TB. I just removed the air hose to expose the air side of the TB. I also unbolted a bracket holding a bunch of vacuum lines and a metal tube that attaches to the rubber air duct between the air cleaner and the TB. I had to do this to get enough slack to pull the air duct off the TB. Then I used 3M "Throttle Plate & Carb Cleaner" on the plate and hinge and pretty much every surface I could reach through the opening I had access to. Again, I don't think this was the best way to do it, but I figured that if I had SOME improvement afterward that I could go back and do a more thorough job. I used a shop rag and made several passes until it came out clean. After putting everything back, it did take some turns to get her started. But it absolutely, completely solved my problem. I was amazed the difference. It's been awhile since I did the treatment, and the problem has never recurred.
For cleaning, I wiggled the throttle plate back and forth while spraying with the cleaner. First, I stuffed a rag behind the plate to prevent too much of the cleaner from entering the fuel system. I did a lot of rubbing with a clean shop towel to remove as much black gunk and soot from the hinge of the plate as well as the plate an all it's edges. I did dry things up with a rag, and let it set open for an hour to dry before putting the air duct back on.
Again, I'm definitely NOT an expert, but this worked for me.
I probably did not do the cleaning in the most thorough, correct way in that I did not first remove the air cleaner before cleaning the TB. I just removed the air hose to expose the air side of the TB. I also unbolted a bracket holding a bunch of vacuum lines and a metal tube that attaches to the rubber air duct between the air cleaner and the TB. I had to do this to get enough slack to pull the air duct off the TB. Then I used 3M "Throttle Plate & Carb Cleaner" on the plate and hinge and pretty much every surface I could reach through the opening I had access to. Again, I don't think this was the best way to do it, but I figured that if I had SOME improvement afterward that I could go back and do a more thorough job. I used a shop rag and made several passes until it came out clean. After putting everything back, it did take some turns to get her started. But it absolutely, completely solved my problem. I was amazed the difference. It's been awhile since I did the treatment, and the problem has never recurred.
For cleaning, I wiggled the throttle plate back and forth while spraying with the cleaner. First, I stuffed a rag behind the plate to prevent too much of the cleaner from entering the fuel system. I did a lot of rubbing with a clean shop towel to remove as much black gunk and soot from the hinge of the plate as well as the plate an all it's edges. I did dry things up with a rag, and let it set open for an hour to dry before putting the air duct back on.
Again, I'm definitely NOT an expert, but this worked for me.
Thanks for the reply:
I am also looking for suggestions beyond the Throttle Body Cleaning. On 1-4-09 I did as you did, removed the airbox, used cleaner to get back as far as I could, used a rag to clean things out and did this both with the car not running as well as the car running.
Unfortunately, all it did was make my exhaust smell bad and did not solve the issue. I'm having a tech come over to the house on 1-5-09 to hook up a computer to the ECU to see if it can tell me anything.
So far I've:
1.) Replaced PCV Valve
2.) Put in Chevron with Techron into tank 91 Otane.
3.) Replace All six plugs with OEM plugs
4.) Replaced O2 Sensors with OEM
5.) Cleaned Throttle Body with Throttle Body on the car using cleaner and rag
6.) Will hook up to Computer on Monday 1-4-09 to see if it throws codes.
If anyone on Gods green earth has had the exact problem i'm having, please PM me or post to site. I've read other threads on this and some say it could be the EACV - well, since my car Idles just fine I'm not positive its the EACV.
Hell, could it just be clogged fuel filters?
Re-hash of issue: Car idles just fine. However, when going from High RPM (only about 3000 up) and let off gas quickly, -- Car seems to lose it brain, Idle Yo-Yo - computer tries to compensate - continues to Yo-Yo up and down and eventually dies. (I love my car) - Makes me want to take a second mortgage to fix it:
I am also looking for suggestions beyond the Throttle Body Cleaning. On 1-4-09 I did as you did, removed the airbox, used cleaner to get back as far as I could, used a rag to clean things out and did this both with the car not running as well as the car running.
Unfortunately, all it did was make my exhaust smell bad and did not solve the issue. I'm having a tech come over to the house on 1-5-09 to hook up a computer to the ECU to see if it can tell me anything.
So far I've:
1.) Replaced PCV Valve
2.) Put in Chevron with Techron into tank 91 Otane.
3.) Replace All six plugs with OEM plugs
4.) Replaced O2 Sensors with OEM
5.) Cleaned Throttle Body with Throttle Body on the car using cleaner and rag
6.) Will hook up to Computer on Monday 1-4-09 to see if it throws codes.
If anyone on Gods green earth has had the exact problem i'm having, please PM me or post to site. I've read other threads on this and some say it could be the EACV - well, since my car Idles just fine I'm not positive its the EACV.
Hell, could it just be clogged fuel filters?
Re-hash of issue: Car idles just fine. However, when going from High RPM (only about 3000 up) and let off gas quickly, -- Car seems to lose it brain, Idle Yo-Yo - computer tries to compensate - continues to Yo-Yo up and down and eventually dies. (I love my car) - Makes me want to take a second mortgage to fix it:
I'll be jumping the OBD I connector today and reviewing the codes. I'll post back my findings and post if this corrects to the problem to help others with this same issue.
Regards.
Regards.
did you try replacing the water temp ecu sensor? I'm starting to have a similar issue, idle a bit jumpy and starting to run rich every other start under wot.
I have finally fixed my issue. The sensor up in the grill area was unpluged. Is that a outside air temp sensor? Once that was plugged in all the stalling problems went away.
That sensor is for the climate control unit and I can't see how that would affect the idle other then it may cause the ac compressor run more which if the idle control circuit is not working properlly stall the engine.
Larry -
I have been reading through and following this thread and it seems like I have two problems. 1. ) is with the idle slowly fluctuating up and down as the car can't seem to find the right idle. It attempts to find the 700 / 800 rpm mark and slowly drops, but once it gets close, it wants to jump back up. (that's the idle issue and sounds like it could be the clogged idle passage as you described.
The Second issue is that my car runs rich. It smell like an older 50's 60's car and I smell too after I stay in the garage too long. I can even taste my mouth as it tastes different after breathing in the fumes. Would this be an injector issue or a fuel regulator issue you think? It seems to be running way to rich. In addition to this, if the car is really warm and I turn off the car. It won't start. I crank and crank and smell gas. I have to let the car sit for about 10 to 15 minutes until it will fire. Some think it may be leaking injectors.
Well, to add to this theory, I checked my oil dip-stick and guess what? The oile is higher than expected. I never fill my car above the high-point on the stick and when I checked it this evening, it was about a 16th to 1/8th higher than the high/full point.
I had a similar issue. Turns out to be clogged injectors. Cleaned the injectors and the idling after accelerating gone and no more running rich. Regarding difficult hot start maybe need to replace main relay.
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In the service manual there is an idle adjustment. I think you may wish to try that. It is NOT a screw adjustment, it is done by jumping the service connector and running the engine at idle. Look in the 1995 service manual, it is there.
Regards,
LarryB
.Regards,
LarryB
Larry, thank you for the reply. It's kind of a pain the a$$, but that fact that I purchased the car so that my father and I had a project makes it worth the "fun" trying to figure out what's going on.
He's more in to older cars, you know his chevelle, which is cool.. anyway
As an FYI - we pulled the entire throttle body off and cleaned just about every nook including the three top (very small) holes just inside the TB. The battery on the car has been disconnected for about a week now and we are putting in a set of injectors on the car.
I will run through the manuals suggested setup for idle. My issue is not like the others here, My idle does not bob up and down wildly, it just doesn't want to idle at 850, it wants to idle at 1100, 1200.
So, after we put in the injectors and attempt to set the idle, we are going to start looking for vacuum leaks. Any thoughts. I'll keep you all updated on the mystery high rpm idle. -- I'll hunt for the 95 idle adjustment as you suggested.
He's more in to older cars, you know his chevelle, which is cool.. anyway
As an FYI - we pulled the entire throttle body off and cleaned just about every nook including the three top (very small) holes just inside the TB. The battery on the car has been disconnected for about a week now and we are putting in a set of injectors on the car.
I will run through the manuals suggested setup for idle. My issue is not like the others here, My idle does not bob up and down wildly, it just doesn't want to idle at 850, it wants to idle at 1100, 1200.
So, after we put in the injectors and attempt to set the idle, we are going to start looking for vacuum leaks. Any thoughts. I'll keep you all updated on the mystery high rpm idle. -- I'll hunt for the 95 idle adjustment as you suggested.
I only experienced a slight idle problem this week after driving the car for the first time driving in 9 days. When the car was warm, the idle would suddenly dip real low and it would pick back up again into the 1200 rpm range until it was at full operating temp.
When I drove it that day, the car stalled at a stoplight. I did notice the rpm's were at 600ish. So as soon as I got home I went through the search function and found one of Larry's post on how to clean the throttle body. So when I removed the intake I noticed oil inside the intake pipe as well as a little in the throttle body. Then I pulled my PVC off and it looked like it had never been changed before. It had caked on oil residue and it was stuck. So after replacing the PVC valve, I opened the butterfly and sprayed throttle cleaner, and the plastic straw that attaches on the nozzle flew off inside the intake:tongue: 4 hours later I got it out and sprayed 2 more cans of it inside the throttle body, then inside the 4 vacuum sources on top of the throttle body, and drove it 550 miles between yesterday and today. Idle stayed consistent at 900 rpm's, and no oil inside the intake pipe.
When I drove it that day, the car stalled at a stoplight. I did notice the rpm's were at 600ish. So as soon as I got home I went through the search function and found one of Larry's post on how to clean the throttle body. So when I removed the intake I noticed oil inside the intake pipe as well as a little in the throttle body. Then I pulled my PVC off and it looked like it had never been changed before. It had caked on oil residue and it was stuck. So after replacing the PVC valve, I opened the butterfly and sprayed throttle cleaner, and the plastic straw that attaches on the nozzle flew off inside the intake:tongue: 4 hours later I got it out and sprayed 2 more cans of it inside the throttle body, then inside the 4 vacuum sources on top of the throttle body, and drove it 550 miles between yesterday and today. Idle stayed consistent at 900 rpm's, and no oil inside the intake pipe.
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