96 LQ1 Not Running

[Artemis]

Okay, I'm going to try to explain everything that has been done to this car and where we sit now.

95 GTP, engine threw a bearing. Lucky for me I had a spare 96 LQ1 with harness, ECM, etc. Me and my buddy built it up from the ground. All new gaskets, new CPS, TPS, plugs, wires, timing belt, tensioners. We installed the engine into the car, and got it to start. It wouldn't really run without a little throttle. After one successful run of about 20 seconds or so it wouldn't start again. Starter wouldn't even turn over.

So now we wait until the following day. Try again, car starts but dies after a few seconds, car will turn over again but not start and you can smell gas. Pretty sure its flooding. Then the starter wont turn over again. We have some electric gremlin.

Yesterday, try to start again. Starts first time, dies after a few seconds just like the previous day. Then we smell gas and it wont start. We decide to track down electrical gremlin because starter wont turn again. Well, alternator positive rubber boot isn't on and the metal power steering line is touching. Fix that up. Now it will turn over each time. But it struggles to start. We can get it to consistantly start with WOT, but it wont go above 1k rpms and dies after a second or two.

Not sure if its not getting enough gas, or maybe that the fuel pump cuts off after car is running? Could we have fried the ECM? MAF? IAC? Not sure how to check FPR, its not spitting out gas. I'm kind of at a loss, was hoping for the 60degree Gurus to give some advice.

[Artemis]

Todays update

My buddy thinks its the ECM but I have my doubts. We are able to read it with an OBD2 scanner. Its really acting odd though. Earlier today it was starting for a few seconds but not flooding. But now its flooding again and nothing has changed really. Scanner is telling us something however that may be a clue. -39F coming from the coolant temp sensor. Its definitely plugged in, and both the 1 lead sensor on the head under the crossover and the 2 lead sensor in the LIM are brand new and plugged in.

Other readings from the OBD2 scanner.

MAP 29.8
Calc LOAD(%) Have seen 3.1 and 0
MAF - 0.250lb/min

I assume the MAP is reading normal. These readings are when the car is set to ON, not running. If I unplug MAP is goes to 0. IAT reads good temps.

Would you still be able to read live data if the ECM was toast?

[pocket-rocket]

In short, most likely not, depending on what part of it were bad. That temp doesn't sound right, so the PCM is thinking it's extremely cold out and is going to want to run the engine really rich. I would run a continuity test on the temp sensor wires to the PCM to rule out wiring.

[Artemis]

Just an update, I hate my car. But on another note, replaced CTS again, reading a more normal temperature. Had an auto electric specialist look at it, injector pulse length (or whatever you'd call the amount of time injector is open) is about 10x longer than it should be. I've tried 2 ECMs, new FPR, new MAF, new MAP, new pretty much EVERYTHING and it still keeps flooding. Has anyone experienced this before?

[jman093]

Are you certain you don't have a Passkey problem from swapping in the OBD2 PCM/harness?

[Artemis]

I was certain VATS/Passkey issue would result in the ignition getting no power at all, no turnover. VATS was bypassed some time ago, and I believe its an interior harness thing, which wasn't swapped.

[jmgtp]

The long pulsewidths on the injectors sounds like it is because the ecm thinks your engine coolant is well below ambient temp. -39 sounds like the default if it doesnt have any signal from the sensor. You said you replaced it and got a more normal reading, but what is more normal? If the car hasnt been running it should be close to ambient temp. If it isnt, start there since it is a known problem. You replaced the sensor but did you verify that the threads were clean on both sensor and engine? I once had a terrible issue with a no signal knock sensor and it turned out to be dirty threads.

[Artemis]

Last time I had a scanner available, I got 24 F as a CTS reading. Not nearly low enough to flood as much as it has. Btw, the pulsewidths were measured at 80ms while the car was running, instead of 1-4ms.

[Artemis]

Swapped out injectors last night, and ECM again... still acting the same. Only not new sensors are camshaft position and IAC. I'm at a total loss here, not sure what to do next.

[jmgtp]

Start with fixing the CTS. If the car has been sitting it the coolant temp should be at or near ambient temp. Sounds like it isn't your only problem though since I don't think that it would cause a no start. Perhaps it could be the CPS.

[Artemis]

CPS as in cam or crank? Crank Position Sensor is new, and I wouldn't get spark without it. I've been doing some reading up on Cam Position Sensors, do they control the timing of the injectors?

[jmgtp]

I meant crank, I must have missed that you replaced it. I believe the cam position sensor is just for SFI purposes to ensure it is firing the injectors at an open intake valve. I think even disconnected the car would run without it and perhaps revert to MPFI.

So you're getting spark, fuel and you have compression? It is either the cam timing is way off, the spark timing is off or you don't have the right amount of fuel. If you think its flooding try clearing it by holding the gas pedal wide open and cranking (this will not fire injectors).

[Artemis]

Even at 100% throttle it sputters and floods. It appears almost as if it refuses to go into flood mode (turn off injectors). Its 100% flooding, stupid amounts of gas. Like I said before, injectors were staying open 60-80ms instead of 1-4ms.

[Artemis]

Hooked up scanner last night, CTS was getting 17 degrees Celcius, the outside temp at the time. This weekend I may be grabbing a whole other 96 harness.

[Artemis]

Over the weekend I tried another IAC and Cam Position Sensor. And then I tried a WHOLE OTHER 96 Harness. STILL flooding. The car did run, could it have jumped timing on my brand new belt? Or perhaps the ICM is not sending strong enough spark?