I got my scanner tonight so I decided to scan my GTA. This is the car I am having a hard time getting to start. It will only start when I unplug one of the injector banks. This is what the scanner is telling me. Sorry for the picture of my computure. I have no idea how to get this info out of the program.



Phil

 

use print screen button, and open paint "came with windows" then hit paste.
then save as a .jpg

 

Is the engine running when you got this snap shot?

Assuming the engine is idling, Couple observations:
1) seems like timing is not right. What is the advance at idle with the EST wire disconnected? Do you know about the EST wire and what it does? And thats a high "desired idle rpm" = 937RPM.
2) at this point in time you are RICH; O2 sensor = 0.792V
3) the ECM is still in OPEN loop mode, with run time at 87 sec. That is why both BLM and INt are 128.
4) the TPS is too low = .47V, it should be more like .60V at idle, closed throttle.

It's very hard to tell alot from one snap shot. I highly recommend that you go the the technical Articles on the home page here, and lok under the Electrical section for the idle RPM setting, IAC adjustmnet and TPS adjustment. Complete this stuff, you will learn about the EST wire by doing this.

And, are you sure the the car has the stock Eprom chip in it. I will bet you that it is not the factory one.

 

The motor was idling when this info was taken. With the EST wire unhooked I have the timing set at 6*. What should the desired idle RPM be? It was switching pretty quickly between rich and lean. I did know that the TPS was a little low. Thank's for the info I will check out the tech section. Some day I will figure out why this thing starts so hard.

Phil

Edit: Will I know if the chip is not the factory one just by pulling the ECU and looking at it?

 

With the EST wire disconnected, the static timing should be 6* at idle. So you are good here. However, the idle RPM should be 750RPM, not 937.

At idle or cruising around, the ECM should be switching alot from rich to lean and back to rich, along with this the cross counts should be high. Every time the ECM goes from rich to lean, that counts as one cross count. The ECM only knows that you are above 0.450V (rich) on the O2 sensor, or below 0.450V (lean). You are supposed to bounce above and below .45V on the O2 sensor. 0.45V is 14.7:1 AFR.

How about determining if you have the factory chip in the ECM.

 

I will get the ECM out tonight and take a look. I am also woundering why there is a little over 14* of advance with it at an idle? Thank's again for the help.

Phil

Edit: On a side note, the car idles at about 700-750 RPM in park and about 600 RPM in gear with my foot on the brake. I know that is not the desired RPM you are talking about but I didn't know if it meant anything.

 

Well I got to get the ECM out tonight. When I looked at it under the dash I noticed the PROM cover was allready off it. Here are some pics of the ECM and the prom. I believe it is a factory PROM. I cleared all the codes tongiht as well and I see the only one I have come up every time is code 32, EGR failure. It actualy started tonight with out pulling the injector fuse. I did notice that the car ran much better when I was scanning the car. Turn the scanner off and it would idle rough again. Desired Idle is down to 687 rpm.










What is this thing?



Phil

 

"AUJM" is the number for an '89 L98

 

It is obvious that someone has been in there and missing around. That Eprom may have the right sticker, but that same Eprom could have been reprogrammed.

Anyway, read the technical articles under the electrical section for the idle air setting, etc.

 

FWIW, I was just offering the info for what the code is listed as.....

 

You knew something that I didn't so I thank you for the info.

As far as the rest of the electrical stuff, I have set the TPS to .60 volts at idle. The desired idle will chance each time I run the car. It might be 900 rpm when I start it one time and then 600 RPM the next. How can I adjust something that doesn't stay constant to begin with. I also learned that the injectors should read about 16-17 ohms. The 12 ohms that I am seeing is at the bottom of the scale for these injectors and they probabaly need to be changed. It may not cure the problem but it can't hurt.

Phil

 

Figured it all out this morning. Between the driver side headlight and the battery there are two screws to attach ground wires. One of the screws has two wires on it that go to somewhere in the wiring harness and the other screw I would guess went to the battery. I say I would guess because some really smart guy cut the wire off the second screw and all that was left was the factory crimp on wire end. I ran a new ground to the one that was cut off and what do you know, it starts every time on the second flop. I ordered new injectors this morning. I guess they can't hurt to put in. Thank's too all of you for the help with this. Sometimes it is the simple things that you just don't see.

Phil

 

What did you buy for new injectors, flow rating and brand?

 

I ordered a set of rebuilt bosch series III 22# injectors. They are flow matched and have a 3 year warranty.

Phil

 

thats the same i got.. how is it running

 

It is running beyond perfect. Starts perfect every time and idles way better than it did before.

Phil

 

Can anyone comment on what the YELLOW box above is?
Is it the speed sensor? Would it be for a SD or MAF setup? Thanks.

 

where did you get your injectors

 

I got them from this guy.

http://www.fuelinjectorconnection.com/shop/

Phil