Lt1 Guys I need help.
#1
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Lt1 Guys I need help.
Mods. Long tubes 3 inch exhaust 1.6 rr Comp Cams cam ( ground just like the hot cam ) Supposedly had a tune 1993 Ram air speed density car. Car ran fine until the opti went out with no issues
Issues - Running Rich
Mis Firing
Very low Vacuum
Out of time symptoms
About 2-3 months ago I was driving my car in the rain Car died. Started back up about 10 min latter. drove it home
Car progressively started to miss more and have a drive ability issue Trouble shoot the issue and I had no signal from the opti ( or a weak one when it showed ) and once I got the old one off and took a look it had the normal rust and damage inside.
Purchased a new Delphi optispark. Put it on the car and now I have a perfect square wave to the icm. and the firing order is correct. The car got new msd wires and Tr55 plugs. ( that are now fouled )
Started the car and it now has no vacuum very low ( 10 -12 pounds ) and once it hits closed loop the Short Term Fuel Trim Drops to 1-10 counts.
Smoke tested the intake manifold with no leaks present.
Double Checked wires they are correct.
Iac motor works. Though if you take off the air foil the vacuum comes up a bit as from the advice of others I drilled out the idle air port in the tb. and put it back on and now the iac motor does have more control but did not solve the issue.
Tested the Map sensor compared to readings on the scanner and they are correct.
Found a QDM 1 Fault- Traced this back to the smog pump being deleted.
The car is running at 21-23 degrees at idle on the scanner. Made timing marks on the crank pulled and water pump and this is correct.
Replaced grounds and tried a extra icm and egr solenoid to no avail.
Tried a extra computer and it ran worse. Which does lead me to believe there is a tune in it
No codes and Im out of ideas , Need help!
Issues - Running Rich
Mis Firing
Very low Vacuum
Out of time symptoms
About 2-3 months ago I was driving my car in the rain Car died. Started back up about 10 min latter. drove it home
Car progressively started to miss more and have a drive ability issue Trouble shoot the issue and I had no signal from the opti ( or a weak one when it showed ) and once I got the old one off and took a look it had the normal rust and damage inside.
Purchased a new Delphi optispark. Put it on the car and now I have a perfect square wave to the icm. and the firing order is correct. The car got new msd wires and Tr55 plugs. ( that are now fouled )
Started the car and it now has no vacuum very low ( 10 -12 pounds ) and once it hits closed loop the Short Term Fuel Trim Drops to 1-10 counts.
Smoke tested the intake manifold with no leaks present.
Double Checked wires they are correct.
Iac motor works. Though if you take off the air foil the vacuum comes up a bit as from the advice of others I drilled out the idle air port in the tb. and put it back on and now the iac motor does have more control but did not solve the issue.
Tested the Map sensor compared to readings on the scanner and they are correct.
Found a QDM 1 Fault- Traced this back to the smog pump being deleted.
The car is running at 21-23 degrees at idle on the scanner. Made timing marks on the crank pulled and water pump and this is correct.
Replaced grounds and tried a extra icm and egr solenoid to no avail.
Tried a extra computer and it ran worse. Which does lead me to believe there is a tune in it
No codes and Im out of ideas , Need help!
#5
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It started with a bad opti. Put the new opti on and ran like crap. At least I know its not the timing or firing. Someone mentioned that it could be the Egr valve. But with the lt' headers Im not sure because it wouldn't be bringing in any exhaust back there. Plus I would think a broken diaphragm would have smoked when I had the machine hooked up to it
#6
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It started with a bad opti. Put the new opti on and ran like crap. At least I know its not the timing or firing. Someone mentioned that it could be the Egr valve. But with the lt' headers Im not sure because it wouldn't be bringing in any exhaust back there. Plus I would think a broken diaphragm would have smoked when I had the machine hooked up to it
#7
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Thats what I am thinking. I can hear a knocking in the exhaust as well. As well the car is out at my school , and I can only work on it like 2-3 hours a week Im debating if I can at least drive it home like this . The knock sensor isnt picking up and detonation and the timing is right.
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#8
Do you have the stock Lt1 knock sensor or the LT4 knock sensor?With RR you need to run the LT4SCM in side the ECU it like $50 new. I am running 1.6RR, the cc306.I lost alot of Vacuum to and it was running richer then ****. All you need is to get it tuned.
Last edited by travailrx7; 07-18-2008 at 12:38 PM.
#9
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To the best of my knowledge it is tuned. Dont know on the km. And it ran fine before all this other crap started. So its not like it was cammed and not tuned or ever running right. I plugged in my extra pcm and it ran worse