Thread: Car wont run correctly

Checking the tps now if i can find the correct values. I am going to check base timing as well. Waiting for a friend to come over and help me pressure test everything. I pressure tested it myself and found the vac hose connected to my bov was the wrong size so it was leaking a bit.

Is base timing with a jwt ecu supposed to be 15 deg? Its been a while.

I do have a vac cap on one fitting under the intake manifold after looking around a bit. I am not sure of anything better to replace it with than a better quality vac cap though.

It's been my experience to go back to where the previous work was done, in this case, the radio soldering. If I understand correctly, the car didn't run right after you did some soldering. I would check back there.

.02

After testing and replacing a few parts it seems the problem is in the main harness toward the ecu plug. I am trying to get a hold of an uncut 93 ser or nx2000 harness currenty. Mine has been cut and soldered on quite a few times over the years for different set ups and i think its time to put it out of its misery and start with a fresh one and just run my jwt ecu for a bit.

If anyone has a used one that is uncut and in great shape they can part with send me a pm.

Thanks, Jon

Base timing for jwt is 15.

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Thanks i will check that out. Anyone know where to find what the timing marks are on unorthodox crank pulleys?

Also i am pretty sure its in the harness by the ecu. If i leave the car idle i can touch or wiggle various wires close to the ecu and the car will die suddenly.

Took the engine harness out and cleaned up all of the old crap like wire splices by the ecu and such. Took the afc out of the equation and re soldered everything and used heat shrink. I re installed the harness today and the car runs but seems to not wat to idle at one rpm. It just hunts around randomly at idle anywhere from 500rpm to around 1500.

So where to next? Any ideas?

Reground the MAF and TPS, make sure the TPS is correctly adjusted. Things that were already mentioned above and things I would have checked first. Run over to a parts store and pick up a new engine coolant temp sensor for a couple bucks, if your car still idles poorly after that, you may have ECU issues.

Put a new coolant temp sensor in. Seemed to help a bit. Have to check and re ground the maf and tps tomorrow.

Noticed the bov was opening and closing when the idle was hunting around so i tried to run it open instead of recirculated and the car runs great with the bov venting to atmosphere besides on decelleration. I don't know what would cause this though, the bov is leaking at idle but the car runs much better. Possibly bad bov diaphram or maf?

Nice, I'd get get the MAF and TPS regrounded. With the tools I have laying around I would T in a vacuum gauge to the same line running to the BOV when the car is running. You'll easily be able to tell if the BOV diaphragm is bad. Not too difficult of a thing to diagnose. Sounds like you're on the right track now.

Re grounded the maf and went through the wires for it to make sure the connections were good. Also tried disconnecting the bov completely and blocking the vac line off of course to see if it was bov related. Still the same lopey idle and dies when i come to a stop.

I do have a question about the idle air control valve vac hoses though. Under the im there is a spot where a vlave sits under the middle with one large line going from before the tb to it then a large line coming out the other end going to the idle air control valve.

There is also a smaller vac hose that is by the valve under the middle of the im. I have that one capped off, i seem to remember having it hooked up at some point to the ic pipes with one of my set ups. Does this need to be connected to the ic pipes before the tb as well? I am not running a charcoal canister either.