rich smelly and farty

[themixer]

wicked thanks!

[themixer]

So an update to my issues, I am still having them. I have got my hands on an actual TECH 1 programmer from the dealership. And it seems as if my MAP is reading ok. I also have tracked down a computer and will be trying it tonight. I am also going to check the injector wiring.

After going though my service manuals it said to check this:

HEI Shielding. An open ground CKT 453 (ignition system reflow) may result in EMI, or induced electrical "noise". The ECM looks at this "noise" as reference pulses. The additional pulses result in a higher than actual engine speed signal. The ECM then delivers too much fuel, causing system to go rich. Engine tachometer will also show higher than actual engine speed, which can help in diagnosing the problem.

I did a test of the wire between the ICM and the ECU and it tests OK. But with the ICM hooked up and the key turned should I be getting ground back to the ECU from CKT453?

I am really frustrated with this, the next thing I am going to try is testing all the wires on the ECU troubleshooting that have anything to do with hesitation and poor idle.

[themixer]

Can anyone answer this, at idle my car goes to 100 BLM at idle. Then it starts running all shitty. With the tech 1 tool i can reset the BLM, and when I do this the car evens out even sounds better. Then the number starts going down again, and the shittyness starts again. Am I correct in thinking that the ECU is adding more fuel as its thinking that its not running @ 14.7 to 1 air fuel ratio? If I had some bad injector wiring would the lack of injector going off make the car over compensate the remaining injectors causing BLM to go less than 128?

[3X00-Modified]

Have you tested a different o2 to ensure its not a faulty one that you got?

[themixer]

Yes I have replaced it twice, what should the readings be for the o2 maybe mine are way off

[3X00-Modified]

At idle they will bounce from 100mv to 800 or so.

[Cliff8928]

I've never actually used a Tech1, does it monitor cross-counts?

[themixer]

I will have to look if it does, I went to the junkyard this weekend and picked up another ECU out of a 1992 beretta. This one is an auto. I just went for a drive to night to see if it has cured anything but it still seems to have a bit of a miss at idle. It seems a lot of the hesitation is gone. I have been fooled before with these issues! I will stick on the scan tool tomorrow and drive it to work. Hopefully my BLM is somewhere around 128.

edit: one more question is there any way to tell if i actually have a 5 speed ECU with the tech 1 or scan tool? is there any part number on the actual eprom chip?

In other news.
While my buddy was down with his 1989 2.8 V6 we hooked up the tech 1 at idle his car showed a BLM of 135, and the only thing that stuck out in my mind as being different was his IAC was up around 40, mine is at 20. I am sure that every car has a different learned setting for this but I thought I would mention it.

[Cliff8928]

Yeah, there's a 4 letter code for the specific prom.

[themixer]

what are the codes for manual?

[Cliff8928]

For what year?

[themixer]

any year with 3.1 5 speed 1990 to 1993? Here is the one that I have, I believe its a 5 speed. Took the car out again today it really does seem to be a LOT smoother and no bucking.

[Cliff8928]

That's the first release for a 1991 with the 3.1 5-speed and federal emissions.

[themixer]

cool i am glad I have the right prom on it. Is any of this consistent with a bent push rod or lifter issue? after being out with the car this afternoon i was under the hood, reving the motor up and down. There is a clicking sound when its coming down from revs and it sounds like its under the rear valve cover.

[3X00-Modified]

A bent valve would cause irregular compression on one cylinder that could cause some of those symptoms. Not sure about bent rod or pushrod.