This problem really has me baffled. I just drove 1000 miles this weekend, car performed perfectly. Then yesterday, I go to leave work and it cranks, starts, and runs for just a couple seconds and dies. The engine is completely cold, car sat for 11 hours while I worked.
I probably cranked it 15 times. Everything checked out fine in the engine bay. I then decide to unplug the ecu and reset it. I do this, plug it back in and the car starts just fine. Then this morning, it starts 100% fine and runs good all the way to work.
Go to leave after 11 hours and it's doing the same thing. Unplugged the ecu, sat a minute, plugged back in and it started and ran great.
That brings me to now. Went to go to a friends, 2 hours maybe after getting home and it's doing the same thing.
Is my ecu going bad? I don't even have any guesses.
Well I put the car back together again. I was doing a boost leak test and hooking the coolant lines back up to the oil filter housing. I had the ecu unplugged for about a day when it was sitting in the garage. I plugged everything back in after the car was together and it started up just fine. It idled for the last 20-30 minutes without any hiccups.
I then turned it off and went to start it right after and it was back to doing the exact same thing. RPMs jump up to about 1500 and then as it starts to drop down to idle speed at around 1000 rpm it just dies. I have a check engine light again and I'm going to try and read the code with evoscan but it hasn't been working for me lately, another issue entirely. Does anyone have any input?
Well more development. I came home from work and started it. Cranked up just fine with no issues. 24 hours ago it would not stay running. I then shut it off, and started it back up with no problems. I did this twice.
I then allowed it to fully warm up. Turned it off and it was back to the same old story. Runs for a second then dies. I rented an OBD2 scanner, but it won't connect to my car. I obviously have some wiring issues somewhere because of that, yet I can flash my ecu with no problems. Another total mystery.
I took a video with my phone, hopefully it at least gives a better idea. First time I started it with no gas, the second time I gave it a bunch of gas to keep it going and it seemed slightly more resistant to dying. I'm looking into finding another 98/99 ecu now.
I'd still open up the ecu because a semi-bad ecu can cause all kinds of problems because once I ran my 1g N/T for a full year with mysterious running issues I couldn't find and when ecu crapped out completely a used replacement ecu solved all the issues and I was shocked.
So now I'm quick to open them up and take a close look on both sides of board. I also keep a good spare because a quick swap tells you right away too.
93 Talon TSI (m/t)
92 Eclipse 6-bolt n/t (parting-out)
91 Talon TSI a/t (rip)
As a shot in the dark, what condition is your front O2 sensor in? Is it stock, a rewired/translated wideband? How old is it? Only reason I'm asking is it seems to be freaking out only when it's been running a bit. I've had a similar thing before.
With the 2G's a bad O2 sensor can throw the fuel trims off enough to make restarting the car damn near impossible - I've had that happen in my car when I forgot to plug the front O2 sensor back in. Fuel mileage went to hell and wouldnt' restart. Clearing the ECU let it be ok at startup but as soon as it had some miles on it in open loop, the damn thing was out of commission. found the plug wasn't clipped, and bam, problem was gone.
I just got and tried a new ecu and it is doing the exact same thing. This means it's a mechanical issue. I don't know what would cause this. I even tried the stock ecu that isn't tuned for my 850 injectors. It started, but ran bad (obviously) and once I turned the car off it wouldn't stay running again. I've played with every single electrical connector in the engine bay with no results.
I could really use some help here. Has to be running tonight.
could be wrong, but i think you may have erased yor ecu memory by unplugging it for so long. next time instead of unlpugging the ecu to start it, just start it and rev it right away to keep the engine from dying. (although this is bad for the engine if you do that wayyy too much) if im right, the more and more you drive (without unplugging the ecu) the more memory the computer learns and its able to hold itself over during start up
- Car had been sitting for 2 months
- Worked perfectly before it sat.
- Would crank and then die approximately 4 seconds afterward.
-This was done over 30 times in one evening.
- Most times I could not get RPMs above 3000 without it dying unless I held WOT as I cranked it, but it would die after the idle finally settled.
- Eventually, I started to hear a "clicking" sound from the center console behind the radio.
To my dismay, it looks like an ECU cap leaked onto the board.
I replaced the ecu with one I knew worked, and problem solved. Car cranked and stayed running. I let it warm up and took a spin with no problems to report.
If you haven't pulled your ECU you might want to ASAP.
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