82 cross fire injection problem

[willis381]

I have a 82 Vette with 29,000 miles. I have never had a problem with it. All of a sudden it started running bad. I thought it was a egr valve or something like that. I do not know much about cross fire but noticed it was not firing one of the injectors. I think both should be firing at idle but not for sure. I moved the wires of the one that was firing to the injector that was not and it let fuel through. so the injector seems fine. i then checked and both have a wire that is hot at each injector. The blue wire and and the green wire I guess are the negative pulse wires that go to each injector. the injector with the green wire does not show it has any ground signal from the ecm (that is the injector not firing). I then went to the ecm and on the white plug teminal 9 is the green wire and it checks good from the plug to the injector. I then took a grounded test lead and probed the green wire outside the plug at the ecm and the injector fired once every time I touch the wire. I guess the ecm would be bad but need to see what you guys think.

 

[Crimson Thunder]

Buy a Renegade Intake for it. It supposed to be the be all-end all solution for the Cross fire.

 

[Buccaneer]

I have a 82 Vette with 29,000 miles. I have never had a problem with it. All of a sudden it started running bad. I thought it was a egr valve or something like that. I do not know much about cross fire but noticed it was not firing one of the injectors. I think both should be firing at idle but not for sure. I moved the wires of the one that was firing to the injector that was not and it let fuel through. so the injector seems fine. i then checked and both have a wire that is hot at each injector. The blue wire and and the green wire I guess are the negative pulse wires that go to each injector. the injector with the green wire does not show it has any ground signal from the ecm (that is the injector not firing). I then went to the ecm and on the white plug teminal 9 is the green wire and it checks good from the plug to the injector. I then took a grounded test lead and probed the green wire outside the plug at the ecm and the injector fired once every time I touch the wire. I guess the ecm would be bad but need to see what you guys think.

To answer your question...Yes, both injectors should be firing at idle. Since you swapped the injector connectors and the "bad" side was then good. Take a look on the fusebox under the dash on drivers side, there are two fuses for the injectors, Inject#1, Inject#2, both are 3amp fuses.

Buy a Renegade Intake for it. It supposed to be the be all-end all solution for the Cross fire.

I see that you are one of those that also know everything about a CF and also can't resist the need to take a jab at the Renegade. I'm sure the info you provided the OP was very helpful with his issue. We need more members like yourself that provide useful information about subjects that they know nothing about. Jus sayin'.

 

[willis381]

I checked the fuses, both are good and I have 12 volts to each plug.

 

[Hib Halverson]

I'd say that, if:
The fuses are good
You've got 12v to the hot sides of the plugs on the end of the injector harnesses.
You swapped the connections and the problem went with the wires...

I'd be double checking the ground side of the circuits and I'd be checking the mechanical condition of the connections at the ends of the injector harnesses. Is that stuff is good then, depending on what the factory service manual says, you may be looking at a new or rebuilt ECM.

As for the Renegade...

My advice to the people who are marketing that part is to:
1) Have your internet evangelists tone down the rhetoric. They may be hurting you more than they are helping. If your product works well, it will "speak for itself".
2) If "Super Chevy" magazine is really doing a story on your product (that has been rumored elsewhere on the CAC), do everything you can to make sure the testing is credible and make public not only the peak power number but also the entire torque and horsepower curves of the "A-B" tests.
3) Don't be too dazzled by "Super Chevy". A lot of your target market (ie: '82 and '84 Corvette owners) don't read that magazine because a) its one of Source Interlink's "infomercial catalogs" and b) it doesn't cover a lot of Corvette stuff. What you need to do is get some good coverage in one of the Vette publications: "Corvette Enthusaist", "Vette" or "Corvette Magazine" and, on that note, my offer--to try and place a story in print on the Renegade as long as my conditions are met--which is detailed in threads elsewhere on the CAC, still stands.

 

[Crimson Thunder]

I actually know little about the Cross-Fire but, i've been having a good time following the loooong thread on the Renegade in the C4 forum. I really do hope it gives you guys the results your looking for. Just learn to take a joke.(I bet Hib laughed at it)

 

[geekinavette]

I'd say that, if:
The fuses are good
You've got 12v to the hot sides of the plugs on the end of the injector harnesses.
You swapped the connections and the problem went with the wires...

I'd be double checking the ground side of the circuits and I'd be checking the mechanical condition of the connections at the ends of the injector harnesses. Is that stuff is good then, depending on what the factory service manual says, you may be looking at a new or rebuilt ECM.

Yep, as long as the wire between the injector and the ECM connector checks good, then either that edge-card connector is not making a good connection with the ECM board, or that injector driver circuit is toast.

 

[willis381]

I replaced the ecm and right away both injectors are firing and it runs good. As soon as I started it I got a check engine light. It has never come on before. I checked the codes and it has a code 42 in it. I think it has something to do with the igniton module. What do I need to check? I did put the old computer back in and the light doesnt come on but the one injector doesn't fire. I cleared the codes a few times after I dove it and it always comes back on right away.

 

[Buccaneer]

I replaced the ecm and right away both injectors are firing and it runs good. As soon as I started it I got a check engine light. It has never come on before. I checked the codes and it has a code 42 in it. I think it has something to do with the igniton module. What do I need to check? I did put the old computer back in and the light doesnt come on but the one injector doesn't fire. I cleared the codes a few times after I dove it and it always comes back on right away.

Good news that its working again, bad news you have a CEL. Here are some ideas, but it would be best if you purchase a 82 Corvette GM Shop Manual which is filled with good information. Ebay has them from time to time for around $20. Good luck.

Typical causes for this code include: [FONT=Arial,Arial]
[FONT=Arial,Arial]1) EST line is open or grounded [/FONT]
[FONT=Arial,Arial]2) PROM may not be seated properly in the ECM [/FONT]
[FONT=Arial,Arial]3) Poor connections between ignition module and ECM [/FONT]
[FONT=Arial,Arial]4) Poor routing of EST harness and/or poor quality ignition wires (EMI induced electrical noise) [/FONT]
[FONT=Arial,Arial]5) Faulty or incorrect ignition module [/FONT]
[FONT=Arial,Arial]6) Faulty ECM [/FONT]​

[/FONT]

 

[willis381]

After checking the wiring everything is good. I went ahead and replaced the ing. module b/c it was the original one. Nothing changed cel comes on as soon as I start it. So I ordered another ecm and have it in there now and I don't have a cel on. But it runs horrible idles up and down rapidly. No codes and both injectors are firing. I run out of ideas except could the problem be the prom. I checked it and it looks good and is seated.

 

[geekinavette]

When you turn the ignition on (don't start it) look for a single flash of the CEL, then it should turn on solid (until started).

If this doesn't happen the ECM is defective.

 

[willis381]

I have never heard that. When I turn the key on without starting it the light comes on without flashing. Could I have got 2 bad ECM? I bought these at Oreily's and they are remanufactured. Where is the best place to purchase one, I have to try a different brand?

 

[jdp6000]

I have never heard that. When I turn the key on without starting it the light comes on without flashing. Could I have got 2 bad ECM? I bought these at Oreily's and they are remanufactured. Where is the best place to purchase one, I have to try a different brand?

You could have bought two bad ECMS. You symptoms changed with each. Try one more.

If you have the old one look at the plug on the ECM for the injector thats not firing. Is it clean and straight.

I don't think this has nothing to do with the problem. On the firewall on the passenger side where all the wires from the injectors go you will find several very large connectors. They are behind a removable box. Open it up and clean the connectors. Mine were corroded badly and causing al kinds of weird problems.

I think I bought my ECM at a NAPA store....I think..