Gamezilla

Okay, my car has been having a wealth of problems since about a month ago. The more I replace, the more goes wrong. Well, heres the symptoms real quick -

Does want to make more than 7psi of boost. After about 5psi of boost it runs ***** out rich. After 4k it runs rich as hell too, and has a lot of trouble getting up to 8k. Has some hesitation points until 4k. Usually the higher i rev it the more i feel hesistation point until 4k, then it falls flat on its face. Primary injectors (which are fairly new 850cc's) make loud clicking noises. So loud I can hear it clearly over the rest of the engine. Brand new TPS sensor reads fine at closed throttle, but WOT one of the readings is off my chart, the other is just over 8v. Smooth transition, but at about half throttle its in the desired WOT voltage range. Car will die randomly sometimes. When it does, if I take the key out of the ignition all the dash lights stay on and a weird buzzing noise comes from under the UIM. The buzzing slowely dies, and after about 30secs stops and all the dash lights go off. When moving the wiring harness around (with the key out of the ignition) it has sparked when an exposed wire touched the intake manifold.

Currently the harness is out of my car and laying torn up on my living room floor. All but 3 of the connectors are broken. most unusable again. Over half the wires have places where they're exposed. My dangling knock sensor had the wire frayed about 3" from the actual sensor. Engine, turbos, intake piping, vacuum lines, and ignition are all in perfect condition. ECU isnt even a year old. These problems did not start after any mods or racing. I was replacing some of the worn or cracked vacuum plugs (yes, I already checked these. This is not the source of my problem) and afterwards the car wouldnt boost.

Now, has anyone had any electrical issues like this? I think its my harness shorting out somewhere. The bad voltage readings on the TPS sensor, inability to shut off after the key is out, and sparking suggests major wiring issues. Would replacing the wiring harness (as I intend to do) solve my problems? Is there still a possibility that I have fuel issues (bad FPR, sticky injectors, etc)?

XSTransAm

did you tune the car for the new injectors you installed?

Gamezilla

Yes. Car came pretuned. Worked perfect up until about a month ago. Also, I plugged my friends commander into it and checked to make sure its tuned for 850cc x 4. It is.

alberto_mg

First, list your mods and mileage.

Second, questions:
1. Where are you when you say that you can hear the injectors clicking? Under the hood or in the car?
2. Can you record the sound and post a clip here?
3. When do you hear the clicking? Under wide open throttle, part throttle or just idling?
4. Why are you running 4 850s?

Your TPS sensor very likely needs to be readjusted and your idle may need to be readjusted as well as per that thread in the archives. I know you just did it, but it sounds like you did it incorrectly. Don't flame me for saying it.

That buzzing sound you hear is probably the idle speed controller. I have a feeling that since your TPS is off, its throwing off the ability for the ISC to control the idle and stalling the car. I could be wrong.

If you have a Power FC it could also be that it needs to relearn the idle.

My guess is that the wires leading to the injectors are fucked up and shorting out when the ECU sends voltage to them trying to open them up. It sounds as if you need a new wiring harness or at least cut/splice/solder lots of new wires to save the piece of crap you currently have. Ray at Malloy sells them for 660.

Give us some more info if you got it.

Gamezilla

Okay. First off, I cant start the car. I have the wiring harness laying on my living room floor. Over half the wires were exposed. My knock sensor had a wire that had completly frayed open. Most of my clips are unusable again. The thing litteraly was breaking apart as I tried to get it out of the car.

Mods are - 850cc primaries on stock rail, PFC, intake, DP, MP, exhaust. Turbos have about 9k miles on them. Maz-max (a good shop that rebuilds stock ported engines) built the engine about 12kmiles ago. Thats it. Car was tuned and it ran fine up until about a month ago. Then it was a million problems at once. I replaced the whole ignition system. I was about to replace the whole fuel system. I checked the voltage on the tps sensor.

Here's the best I could calibrate the original tps sensor -

Top wire - 1.5v close, off the chart open
Bottom wire - .1v close, almost 9 open

I spent about 30mins trying to adjust it and thats the best I could get. I gave up. Bought a new one. Here's the new ones reading -

Top wire - 1.2v closed, off the chart open
Bottom wire - .2v closed, 8v open

So I got it a little better, but not close enough. I adjusted the idle screw to drop my idle to 900. It still has problems holding 900. It just randomly picks an idle to hold. Sometimes its 1000, then 800, then 1200. It'll be 1100, then I'll drive down the street, stop, and now its at 900. Drive some more. Next time I stop its something else, like 1000.

The injectors are noisy enough that with the hood open I can hear them loud and clear. Inside the car I cant. If I walk about 15ft away from the car all I can hear is my exhaust and the injectors clicking, nothing else.

Rx-7$4$me

For the TPS just look on the commander. The bottom voltage number should be around 1.35 I believe at closed throttle, and then close to 5 at WOT. The top number is based off of the bottom number so it wont make a difference what that is.

Did you make sure on the power FC to set the primary Front and primary Rear to 66 %?

mad_7tist

are you sure the clicking noise is not a spark going to ground instead of to the plug?

alberto_mg

all good points to check after you get a wiring harness.

i need to buy one too....

you said everything was fine till a month ago - what happened to change that? did you do any work or wash the engine or something like that?

Gamezilla

I was working in the engine. I swapped out all the worn and rock hard vacuum plugs and made sure all my vacuum lines were in good condition. Right after I did that it went nuts. I went over exactly what I did a million times and I know I didnt leave anything unplugged or plugged the wrong thing. I think I might have cause a wire to expose itself when I moved the wiring harness around to get underneath it.

And that clicking noise could be anything. Im not sure if its the injector itself. Whatever it is, it doesnt go away the faster it revs, it just starts clicking faster. And when the secondaries come on the clicking doesnt seem to change at all. I think it is grounding itself when it should, or I have some short in the harness.

Also - kinda late to check the PFC, but I doubt something like that would make it go nuts. I hadnt touched the ECU since I bought the car, not even with a commander. in fact, it wasnt until after it broke that i plugged a commander in just to watch what it was doin.

alberto_mg

Yeah, you probably broke some wire (maybe one that goes to the fuel injectors) while doing the vac lines. Its very easy to do. Just look at them sideways in anger and the wires will break.

I'm not sure how successful you will be trying to redo your already fucked up harness. I'd guess little to none and you'll probably waste a **** load of time ******* around with it.

Gamezilla

Ya. Its not so horrible since Im only using like 10 of the original connectors, but even then I've done maybe 1/10th the work and already gave up. Its confusing as hell and Im getting lost in maze of chared black wires trying to run them where they need to go. Im getting a new harness. I'll just yank the connectors I dont want out of the new harness and rewrap it.