running rich, hard start cold, ???

'88 Wagoneer Limited, 4.0

When the motor is cold it will crank all day, but never start....a small shot of either and its running. However when it runs it runs very rich.....as in it smokes a little.....a little like a freight train Seems to have a miss at idle and throughout the lower rpm range, when reving above around 2500 to 3000 it seems to clear out.

Today, we tested all the sensors, all checked out ok and within specs except the TPS....there are two connectors going to the sensor, on the one that is flat 3 pin connector we had 5 volts and good ground going in, and the proper specs coming out, however on the 3 pin square style connector we did not have 5 volts in, we checked and had conntinuity from the pin to the ECM connector, but still no input....we ran a jumper wire from the flat connector to get the 5 volts in and ran a jumper wire for the ground just to make sure it was good, and tested within specs, but when motor running it did not make a difference.

Then we checked and the no. 1 and no. 2 injector plugs were switched, so we put those back to correct and it seems to run a little better, but no where near good.

The ECU seems to be a replacement and fairly new, however it is not mounted down in the body, just laying on the console under the dash, I know these things are very ground sensitive, could that be an issue?

Any help would be greatly appriciated.

Thanks,
Justin

anyone?

You definitely have to fix any grounding problem before going any further, or the electric gremlins will craze you. Yes, the ECM is VERY sensitive to this.

(all of this is assuming similarities between your 88 and my 93, which I am not sure of... if I had your problems, this would be my reply)
First, with the no start... I'd be inclined to check the fuel pump relay... it is used for starting, and then the ballast regulator takes over for running... Thus, once running, it does fine. There is a relay in the Power Dist. Center that runs the fuel pump for starting,and one in front of the Power Dist. Center that controls the switching between the two systems. Consult you FSM for details...
Also, the fuel system is checked, or has a check valve, that is to keep at least 20 psi of fuel pressure on the rail for at least 30 min. Even without guages, this can be checked. Wear safety glasses, and after thirty min. check for "reasonable" fuel pressure at the fuel rail by deprssing the pin in the schrader valve without ever starting the rig, or having the key on. Be careful, fuel will shoot out, and of course, that is dangerous.
Secondly, as for the overfueling... I'd start at the o2 sensor. Should have a resistance reading of 5-7 ohms. Other things can contribute, but I am always inclined to start with the quick, easy, and free things first...

Best of Luck to you...

TheRasper.

Although I didn't address it, I agree with JLDiaz... fix the ground, first off... Before anything else. Ground problems are crazy, two fold things... not only do they cause things to not work, but also cause other things to operate improperly when they share a ground connector that is not properly grounded, and one "backfeeds" another. When you have unrelated systems failing at the same time, always, ALWAYS start looking at common grounds.

Again, best of luck, my friend...

TheRasper.

Thanks for the replys,

I will mount the ecu in the stock location and give that a try, I have already checked to see if I'm getting fuel when cranking and the answer is yes, I depressed the schrader valve and had someone turn the key, as soon as it hit the run position I heard the fuel pump and it shot fuel all the way to the fender! But, I have not checked to see if it is holding preasure, is there a way to check the fuel preasure regulator? My thought is that if it is allowing way to much fuel preasure on the rail it could cause problems? I'll also check the o2 sensor when I mount the ecu.

Thanks for the help,
Justin