Ok...2.8l. Few questions.

1. What is the sensor/sender above the oil pressure switch? The one down above the oil filter. Mine is leaking I believe (I'm getting smoke off the exhaust right under there, and those two sensors are covered in oil.

2. I adjusted my TPS today because I'm having starting problems. It was sitting at .30v so I'm guessing that's why it wasn't throwing a code. I had to push the thing as high as it would go to only reach .51v. Also, at WOT it would only read 2.5v. I thought it should read higher than that. Is it possible my TPS is going out?

3. This one will be the long one. I'm having cold start problems with my car. Was running great, starting great, then pulled it in the garage to change my struts. After that it won't start cold unless I give it gas, and will stall unless I babysit the throttle, until about 160* or so, then it evens out. Found out that the pickup in the dizzy was bad, also had to replace o-ring. Coil tests ok, ICM tests ok, plugs/wires test ok. Ohmed out injectors, all passed. Timing was set the proper way, wires are correct on dizzy, also new cap and rotor. Cleaned TB, cleaned IAC, set TPS. Started car, and it seemed to fire up faster, but then idle was slowly creeping higher. At about 2500 rpm I noticed engine warming up fast, got a plume of smoke from leaking senders near oil filter, so shut it off, and had to call it a day. Also, lower idles below 1k feel really rough. Car used to idle smooth at 7-800 rpm, now at those speeds, lots of vibration, engine just doesn't sound healthy.

Two things I have not been able to do....check fuel pressure (don't have tools, and cannot afford dropping $150 at parts store to rent one) and have not checked vacuum (same reason as above). I realize that these two things are pretty major, but I have combed every inch of vacuum line, all are hooked up, and all hoses are near new. Car really feels like fuel delivery is ok, but ya know what that's worth. Also, ECM throwing no codes.

Anyway, I need some help here, I'm hoping there's some things I have missed. I have NOT adjusted the idle screw, as before this all started, it was idling fine. I will be able to get back to the car tomorrow, so if I have a list of things I can check, I'll be all the happier.

 

For #1 thats the oil pressure sensor
Does it look like this?? Then thats what it is


I would say first check all the vac. lines and make sure nothing got bumped look and if you had a vac. leak that could cause some idle issues. Check out the wire connections to anything you might have bumped?? Its just a few thoughts

Is you car showing a check engine light? If so use this method on this link and then youll can read the code and it might point you in the right direction. Hope this helps.

Heres the link to check the codes https://www.thirdgen.org/service-eng...ht-error-codes

 

No codes from ECM. Checked and rechecked vac lines, everything is connected. Checked and rechecked all electrical connections. Battery is good and holding proper voltage, grounding strap is good condition and grounding proper.

That is the bottom one, and I know I installed it correctly. The one that I think is leaking is the one above it. It's longer, single wire (didn't get a chance to check the color of the wire).

 

J, possibly thats the fuel pump cutoff switch, i just had mine replaced last week. It shuts off the fuel system if it sees a zero PSI condition. also, if you can't get a fuel pressure gauge, let me know and I'll check with my guy larry and see if we can use his.

Mike

 

1. 2.8s have 2 oil pressure units. NEITHER should be a 3-wire. One is a 2-wire and is for the fuel pump switch. The other is a single wire and is either for the oil pressure light or gauge in the dashboard.
2. With the ignition on, disconnect the TPS and put a meter between the black and gray wires. You should read close to 5V. Go from there.
3. MAF sensor is dying.

 

That was the first thing I did before adjusting TPS. Reads 5.04 if I remember. But to set TPS in correct range, I have to rotate it as high as it will move, and still only reaches 0.51v. Transition to WOT is smooth, but tops out at 2.5v. Is this TPS proper? Or on its last leg?

 

the tps is shot, it should be 5v at wot

but before u get a new tps u need to make sure the refrence wire at the tps has 5 volts, if that wire only shows 2.5 then the ecm is bad

 

I'm not near my car or manuals, but I'm guessing the reference wire is the one that has constant power, not the one that changes with throttle. If that's the case, yes, it has constant 5v

 

yeah thats right, so if u go wot and ur tps only reads 2.5v that means its bad

 

New TPS is having worse problem than old. Cannot even get it to. 5V with it pushed all the way up. Starting to wonder if it's idle screw issue, as this directly rotates TPS. After setting min idle, still have same issue with not hitting correct voltage

 

Idle screw has VERY minimal effect on TPS output (and yes, Ive done serious hogging on the screw with a DMM measuring the output of the TPS).

Check for a problem in the black wire... If a new TPS isn't reaching full 5V at WOT, there could be a problem on the ground side that's eating power, similar to 2 bulbs in a row...

 

I thought it may have been the ground too. Stripped back the insulation and ran a wire to batt.... Same thing, no change.

 

TPS doesn't ground directly to the engine or battery... The ECM provides the ground to the TPS as well as the IAT (IIRC, it's either that or the CTS, can't remember which right now).