If I crank it the car turns on. It just stalls out immediately. The tach moves, the fuel injectors put fuel in the cylinders, the car dies. Half the time it smells like gas, so I know its getting in there, just not sparking.
I know my ignition coil is fine. I know my plugs are good. I know that at least 5/6 of the wires are working. Yesterday everyone said that the distributor cap was good.
Your ICM is likely working. If you have a timing light try checking ignition timing as suggested earlier by a member. Also, it would be helpful if you could review and answer All the questions we have asked. Thanks
Ok y'all. I gotta admit I feel pretty stupid for checking this so late but I ran a fuel pressure test today.
Sure enough, I had extremely low pressure. 1 whole PSI.
Looking around the forum I came across this how to guide by Brocephus. https://www.fiero.nl/forum/Forum2/HTML/096769.html The intro looks like something I would write in a diary lol. Engine running like trash, misfires, large rpm drop if you give it too much throttle, etc.
Another one of my symptoms was that the car got harder and harder to start with less gas in the tank. Started right up when full, I had to feather the gas to start it when it was under half, didn't start at 1/4. My guess is that there was enough static pressure in the tank to help the fuel pump get gas into the lines and as there was less and less gas, there was less and less pressure helping the fuel pump, making it harder to start.
I ordered a fuel pump and I'm doing the change out tomorrow. I'm really hoping that solves my problem but I have a lot of faith in this one.
So the car runs fine now. Idles well and drives ok. There's just one last problem I'm having that might be related.
When I'm coming to a stop light in 3rd, I usually drop it into neutral and apply the brakes. However, when I do this, especially in third, the revs drop like a brick and it usually is very slow to get moving again, with a lot of misfiring until the engine gets itself together and decides to start working properly again. I've noticed a similar thing when coming out of second, but the revs don't drop so hard so there's less of an issue. I'm not sure about fourth. If the trend is the same, I assume going from 4th to neutral will kill the engine.
Am I just driving the car wrong? For now I think I'll try and downshift when I come to a stop light as much as I can.
Yeah. Looks like a code 23 and 33. 23 Doesn't make a lot of sense to me. I just replaced the MAT sensor but maybe I bumped it loose when I was messing around with my slave cylinder earlier. I'll have to check that connection.
33 Is interesting. I don't think I have any vacuum leaks but I could be wrong. I'll have to check again
Yeah. Looks like a code 23 and 33. 23 Doesn't make a lot of sense to me. I just replaced the MAT sensor but maybe I bumped it loose when I was messing around with my slave cylinder earlier. I'll have to check that connection.
33 Is interesting. I don't think I have any vacuum leaks but I could be wrong. I'll have to check again
Do that. If everything looks good, try resetting the ECM to force it to relearn everything. Between the battery and C500 connector is an ECM power connector. Open it up, wait a few seconds, then plug it back in.
I went and tested the MAP sensor and it passed. I reset the ECM too like you suggested. I couldn't find any vacuum leaks.
I should add that this problem only happens on the first drive of the day. If I drive it in the morning it will run like a potato until I park it and when I get back in later it will run just fine. Any subsequent drives and it will still run well but that first one of the day always has issues.
I should add that this problem only happens on the first drive of the day. If I drive it in the morning it will run like a potato until I park it and when I get back in later it will run just fine.
Check your Coolant Temp Sensor (CTS) with a multi-meter. It may be reporting a wrong temperature to the ECM.
On a cold engine, both the MAT and CTS should read about identical resistance.
Yeah I made sure to get the right one. I actually just got a gauge sender and installed it today because a previous owner had installed some kind of weird bootleg kind that came with its own single wire gauge which of course broke.
I actually used the old gauge sender as a temporary plug for the ETC while I wait for the new ETC to come in.
Tested the ECT. It failed hard. Looks like it is completely fried. I ordered a new one. I'll post an update once its installed.
ODD that the ECM didn't report an ALDL error code if this is fried.
quote
Originally posted by Addition1291:
Put in a new ECT. No change.
But maybe explains why there's no change... Does Check Engine light come on as engine starts to stall? Any new codes?
I'm starting to wonder if there's a fault with the ECM. This might be hard to track down without live sensor data from ALDL.
Just had to change ECM in my 87 GT for similar reasons. Because cold start idle was awful. Engine would stall, then I would restart and stall again etc. Was watching sensor data with TunerPro on laptop and saw ECM thought engine was "warm" (38C) even when cold. On 3rd Key Off/Restart, engine temp would suddenly read correct (14C) and everything would be fine.
I had a spare ECM that I swapped in and no problems since. I think I have a "cold solder joint" on the ECT input circuit on mainboard in the ECM I had in the car. Most likely where pin C10 is soldered to the board itself. Haven't checked that yet though...
[This message has been edited by fierosound (edited 09-23-2019).]
Perseverance pays...
