Okay...in my previous post I related the following: '91 auto 57K mileage starts and runs fine until it warms up and then starts running really lousy and bucking "acting like fuel problem" this is intermitent sometimes runs great.(Bear with me...new material soon). It previously indicated a #12 error code (EGR valve) which most concurred could manifest itself like this. Well, today I drove it (note: cleared the codes but have not replaced EGR, yet) and it really ran like hell -- but after looking at the codes it seems to indicate a 1 -- no more '12s'(or maybe 10 -- who the hell can tell the difference?!). Anyway, so what's the betting, an O2 sensor? It can't be the '10' (the IAT sensor) can it? HERE'S ONE MORE CLUE...today, I had my wit's about me, and determined that in neutral you can rev the engine (no hesitation whatsoever...it only does it's hesitation thing with auto in 'drive' and driving) and further, that after bucking up a storm , when it does finally shift into the higher gears it runs normally. So is this consistent with O2 sensor shenanigans? HELP!
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More Driveability Madness (The Saga Continues)
- Thread starter Spencer
- Start date
Bad gas? Dirty/clogged fuel filter?
No, I haven't done anything...this just happens out of the clear blue; always after car starts to warm-up. The dealer suggests that an o2 sensor and/or EGR valve would not do this under load (more at idle) and is suggesting that bad coils might do this. Any ideas out there?
Well, the dealer is right that it may be the coils. Under load the pressure is higher in the combustion chamber and a weak voltage may not always be able to create a spark. And I have had coils on other cars cause problems only after the coil got hot. One check you may try is in the dark with the engine cover up, look into the engine bay and have someone make the problem occur (or not). What you are looking for are flashes of blue light. Bad coil wires may also cause your problem. If you see blue flashes, you have the high voltage that is supposed to create your spark in the engine discharging someplace else. No blue flashes doesn't mean the coils or plug wires are in the clear, but flashes definitely mean something is wrong with the spark delivery system. Old cracked plug wires will exhibit this phenomena.
Fritz
Fritz
A mechanic should be able to check the coils easily (or do it yourself) to rule them in/out of the equation. Instructions here: www.danoland.com/nsxgarage/spark_plugs/spark_plug.htm
It will be difficult to see any “blue flashes” as nsx4fun describes since the spark delivery system in the NSX is low voltage until it hits the coil pack (which sits on top of the spark plug). But he’s right, there could be a short in delivery wires and there should be a way to test for that condition (check the service manual)…ok, I’ll do it…look at SM page 11-56, although you should be seeing a code 15 if there is a problem with this circuit.
DanO
It will be difficult to see any “blue flashes” as nsx4fun describes since the spark delivery system in the NSX is low voltage until it hits the coil pack (which sits on top of the spark plug). But he’s right, there could be a short in delivery wires and there should be a way to test for that condition (check the service manual)…ok, I’ll do it…look at SM page 11-56, although you should be seeing a code 15 if there is a problem with this circuit.
DanO
Spencer wrote about engine codes:
>>who the hell can tell the difference?
A mechanic or a patient owner following the procedure listed in the service manual can easily read these. Since this light is reporting the status of the engine to you and since you are having problems with your engine I would try hard to find out what it is saying. Throwing parts at the problem (sensors, coils) seems inefficient especially when you have a computer trying to tell you what the problem is. Coils are easy to measure with an Ohm meter - specs are in the service manual.
>>who the hell can tell the difference?
A mechanic or a patient owner following the procedure listed in the service manual can easily read these. Since this light is reporting the status of the engine to you and since you are having problems with your engine I would try hard to find out what it is saying. Throwing parts at the problem (sensors, coils) seems inefficient especially when you have a computer trying to tell you what the problem is. Coils are easy to measure with an Ohm meter - specs are in the service manual.
Update: Problem Solved!
The dealer replaced the coil packs (all 6)and the car drives fine. I'm getting the impression that this problem is a little more common than we might think. Anyone with a sputtering/hesitation (particularly as the car warms up) would do well to look into this. Here is another citation of the same driveability issue caused by the coils:
http://www.nsxprime.com/ubb/Forum1/HTML/001796.html
The dealer replaced the coil packs (all 6)and the car drives fine. I'm getting the impression that this problem is a little more common than we might think. Anyone with a sputtering/hesitation (particularly as the car warms up) would do well to look into this. Here is another citation of the same driveability issue caused by the coils:
http://www.nsxprime.com/ubb/Forum1/HTML/001796.html
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