CEL is on in my 91'

i did the diagnostic test and i got 2 CEL light flashes in a row then it stopped and kept repeating the 2 flashes in a row. no other lights flashed but the dummy lights were on. I'm not quiet sure how to diagnose this code??

any help would be great!

O2 sensor

Pretty easy, you have a "2" code. This indicates the 02 sensor for the rear bank is sending signals to the ECU it does not like. So first thing, remove the clock fuse temporarily(it is located in the front fuse box on right passenger side wheel well, 7.5 amp, fuse layout on use box cover sticker) to reset it and see if it repeats. Let us know.

Regards,
LarryB

car has been hesitating anywhere under 3k rpm, think this might be the culprit?

Yes for sure. Mileage, maintenance history?

69k miles and tons of history all from the dealer. its already had 2 timing belt water pump changes from them being due for a change since they were older than the life expectancy. and so much more. car was well maintained and was stock until 48k miles. no 02 sensors though unless done when the exhaust was installed, no receipts if so.

quick search shows people using the ebay bosch or NGk units? anyone have any input for the 91 model years?

Tell me about ALL mods. The code typically would NOT be cured by replacing the 02 sensor. The 02 sensor is not bad, it is telling the ECU fuel mix is not correct. I would first check your fuel pressure, then we can discuss next step. But first tell me what we are talking about in detail about the car setup/mods.

comptech headers, high flow cats and exhaust. open element K&N air filter (looking for a stock box now), that's all i know of for engine mods. the rest is suspension stuff. i have the receipts for the install. the stutter/hesitation is driving me nuts. i have to stay above 3500rpm to avoid it when cruising.

from some research i was doing, i was thinking it could be the fuel pump resister, and i also bought a FRAM Fuel Filter, since i have no records of this being changed.

Is it ok to jump the resistor plug and drive to test if it is the resistor?

thanks

Whenever I don't drive my car for awhile, ( month + ) I get a hesitation that occurs but only when I open the throttle too quick. It always goes away after a few days of driving but I suspect it might be just the battery. I have CT headers as well. Maybe yours is related.

car drives great after jumping the connector with a paper clip. new resistor being ordered!

thanks prime!

The resistor if a cheap fix if it is that. Otherwise, replacing the fuel pump (much more expensive) is the next step if the problem still persists.

Don't want to burst your bubble here, but it is not the resistor. This tells me the fuel pressure is low. Buy nothing until you check the fuel pressure. Jumping the resistor, just gives the fuel pump more voltage. A new resistor will do the same, but is not a fix. Get a fuel pressure gauge, report back pressure readings.

HTH,
LarryB

Larry his next thread is " my car wont start " so wait till that one to help LOL

Larry Bastanza said:

Don't want to burst your bubble here, but it is not the resistor. This tells me the fuel pressure is low. Buy nothing until you check the fuel pressure. Jumping the resistor, just gives the fuel pump more voltage. A new resistor will do the same, but is not a fix. Get a fuel pressure gauge, report back pressure readings.

HTH,
LarryB

Click to expand...

I did order a new resistor already. $58 shipped. NBD, worse case scenario I post in the for sale section. the next day i did take the car for a longer ride, and i could still feel some hesitation here and there under the right circumstances.

thanks again, i hope to learn the quirks to these cars quickly.

also to the other poster this is not my first rodeo trouble shooting cars. I've Owed Dozens of DSM's and GVR4's over the last 16 years, with more than there share of problems. i'm just looking for a little help when needed. Ive already learn about the main Relay and fuel pumps and regulator with some quick research. Seems LarryB is the man, maybe i will get out there sometime. I'm from Mass.

MA explains it LOL use to live in Acton near Concord and Manyard right outside of boston

so i should have my banjo adapter and fuel pressure gauge in today. if it is my fuel pump what will this cost t replace at an acura dealer? Is there a set time that this job should take that they calculate off? I'm sure if the tech is not familiar with this procedure it will take longer than normal. I've never used a dealer for any other than buying parts and always twist my own wrenches, but i have no desire to do this job if it turns out to be the pump.

I recommend that the tank be almost empty when you bring it.

I have performed this job before, and I recall about 4-5 hours total labor to R&R tank and replace the pump. I have no idea what "book time" is based on the dealer service. Get a quote first, and see what they say.

Regards,
LarryB

just called my local dealer. they won't replace it unless i buy the pump from them... just reassures me why i never go to the stealers...

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what is the best stock style replacement pump available? i think i read about a denso unit from rockauto, i can't seem to find that thread anymore.

ok so i held out for a deal and a i found a brand new OEM fuel pump unit on ebay for $150, pretty good deal i think. only problem is that part number shows its only for a 2002-2005. my question is is the whole part useable or will i have to use the pump only in my hanger for my 1991? http://www.ebay.com/itm/OEM-BRAND-N...es&fits=Model:NSX&hash=item3a806ac958&vxp=mtr

thanks

I think this will work fine. Interesting the newer "kit" is the same price as the pump alone for earlier models. Sounds just like the waterpump, which is actually cheaper when you get the kit with the cover, then buying the waterpump alone.

HTH,
LarryB

AWESOME!

Thanks Larry

Larry Bastanza said:

Don't want to burst your bubble here, but it is not the resistor. This tells me the fuel pressure is low. Buy nothing until you check the fuel pressure. Jumping the resistor, just gives the fuel pump more voltage. A new resistor will do the same, but is not a fix. Get a fuel pressure gauge, report back pressure readings.

HTH,
LarryB

Click to expand...

ok so i finally got around to installing the FP gauge today. its right around 45psi at a cold idle. goes to 50ish with some engine revs. i believe it should be 42psi at idle correct?

i am starting to think it might be a rear coil pack or spark plug issue? anyone else?

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ok so i just pulled my rear bank coil packs and 1 spark plug from the worst looking coil pack.

they don't seem so bad compared to the others i have seen.

any input would be great!

While you are checking spark plugs and coil packs, also look at the contact ("nut") on the top end (left end in your picture) of the spark plug for corrosion. This plug looks OK, but check the others. Use a flashlight to look into the boot on the coil pack for corrosion in the contact there. Often, that will manifest itself as ignition noise on the radio.

Turbophein said:

ok so i finally got around to installing the FP gauge today. its right around 45psi at a cold idle. goes to 50ish with some engine revs. i believe it should be 42psi at idle correct?

i am starting to think it might be a rear coil pack or spark plug issue? anyone else?

they don't seem so bad compared to the others i have seen.

any input would be great!

Click to expand...

OK, so this tells me your fuel system is OK. Since you have the coils out, insert the plug into each on and check for loose fit. The plug should be tight and it should fight you a little to pull it out of the coil end.

LMK

Regards,
LarryB