Mike96z

but what about the 1351? that could still be the problem right?

Mike96z

NEW INFORMATION!

Got the car scanned again, seems I got more problems:

P0100 Mass Air Flow (MAF) Circuit Malfunction
P0118 Engine Coolant Temp Sensor Hi Input
P1351 Ignition Control Module Circuit High Voltage
P1441 EVAP System Flow During Non-Purge

I think the MAF sensor has failed, I can test it by bangin on it with a screw driver, but the connector is bad on it and I am ordering a new one. If its failed im getting a new one.

Engine Coolant Temp Sensor had a broken wire on the connector before, fixed it but the code hasnt went away so I have bought a new sensor to replace it. And I need a new connector.

P1351 , i am still totally lost, all ignition components and ICM is new.

Os far as the EVAP system, it also had a broken wire on the connector and that fixed it but it is back so I need a new connector.

This is all the things Im going to try, hopefully it gets my car running good enough.

Mike96z

anyone? I need the part number for the GM MAF sensor

96LT1TX

banging your MAF w/ a screw driver wont help anything I dont think... I would fix the coolant temp sensor like Injuneer said, and THEN see what is happening.

I once had a strange code problem w/ my electrical system, turned out I had a short in the MAP sensor wiring. It was stuck inbetween the alternator bracket and the intake and it didnt set off a code for the MAP, but for other sensors near it (in the same wiring batch). If the coolant temp sensor is WORKING 100% and doesnt fix it, then I would move on to finding electrical problems because that is what it sounds liek to me.

Mike96z

no, tapping the MAF sensor housing while the engine is running is a good way to test he MAF sensor, and if the car dies, its bad.

henryz28

I had the same thing happen to me.I changed out the coolant temp sensor and It runs fine.

Mike96z

same thing as in codes or running badly? I know it will make the car super rich and run badly but the MAF is making it stumble really bad and the ICM **** is driving me crazy.

Harvey

How much could a coolant sensor cost? $15 bucks? I'd start with the cheap/recommended stuff first then move on from there.

Mike96z

yes, i got the sensor, having a hard time getting the old one off, pretty stripped so its hard to get to. I already had the new sensor, its just a matter of installing it, but I know for a fact the MAF is bad now because it was a mild stumble every couple minutes, now its a bad stumble every minute or so and sometimes the car doesnt even wanna go when I push the gas, thanks for the help, ill keep yall posted.

Mike96z

Changed the ECT sensor, well see wat happens, also I know disconnecting the battery will reset the codes, how long should I leave the battery unhooked? Thanks

96LT1TX

5 seconds? 20 seconds? 2 mins? doesnt really matter, they will all reset your codes.

How did the coolant temp sensor do? Did things get fixed?

When I had a sensor that was shorting out, it would pop, backfire like CRAZY at ALL RPMs. I had no clue what was going on, I was getting a low voltage to fuel pump code, low voltage to IAT code, random low voltage codes.

Hopefully your new sensor fixed it, because chasing down an electrical gremlin sucks.

Mike96z

Yes it does suck.

Replaced it, only drove it 3 miles to work today, it seemed a little smoother but still stumbled alittle and im sure the MAF is the reason for that because ive had MAF's go bad and its not pretty, runs rich as hell and stumbles and backfired, but I can say it seems to be running a little better. Ill see once I get it out on the highway. thanks

Mike96z

My engine harness connectors came in today, going to replace the MAF Sensor connector, ECT connector, ICM connector, and reverse light connector in the transmission. Hopefully this all helps.

Yesterday I took the MAF Sensor off because it was throwing a code, got some carb cleaner and some qtips and cleaned up the MAF really good, its ported and descreend and it was easily done without messing anything up, put the MAF on, woke up this morning to drive to work and the thing ran really smooth and didnt hesitate or stumble 1 time and I took it up to mid range rpm's, and i reset the codes but the lite came back on istantly so I will get the codes rescanned to see if the ECT and MAf sensor codes are gone, if so, that will be good because the 1441 will be an easy fix, just have the 1351 left again. Ill keep you guys posted.

and car doesnt run hot anymore.

Mike96z

Well I installed all the new wiring harness connectors and cleaned the MAF snesor and new spark plugs, the car runs smoother, doesnt get hot and instead of 4 codes I have 1 left, and guess which one.........P1351. The car still stubles and misses sometimes, but I think I have a better picture of the problem now!!!...........

Installed an A/F Ratio Guage in the car yesterday, took it for a drive, (388 ci LT1, fully built, stock injectors, no tune) and I looked at the guage, at idle it is STOICH but bounces to lean, but I noticed it goes lean when it pops or misfires, and sometimes at idle it goes all the way to lean and sometimes I guess too lean for the guage to read, but when I push the gas goes back up to STOICH. And at WOT the guage reads STOICH but never ever hits rich, but when it bogs, it will read lean..................

So I think I have a LEAN MISFIRE which is causing this whole problem, dont think the P1351 is causing any driveability issues. Is this possible? Could it be the stock injectors or the new fuel pump I put in? Pressure is fine on the pump, have a guage and it never drops. All input very appreciated.

96LT1TX

Sounds like a tuning issue, who did your tune? I would do a data logged run and send it to whoever tuned it for you, or send that data log and a dyno sheet w/ A/F to a mail order tuner to get that fixed... A lean backfire = bad is all I know... maybe someone with a little more tuning experience will chime in.