1990 Corvette

1990 CHEVROLET CORVETTE
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LRMANTE
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I have a 1990 corvette with 104000 miles that starts up nicely. Its a V8 stick. But as soon as it is warmed up the engine starts to sputter and trys to stall. It stays running but with stalling tendencies. The plugs, distributor, ignition module and plug wires are new. I opened the air intake plenum to ensure it was not a clogged air filter. The fuel pump was replaced last year. I reseated the ECM connectors. There are no fault codes reported just 12. No check engine light either. The SYS indicator has been flashing for years but never of any consequence. I read that is probably due to contacts in the control panel making poor connections. Please advise
Jun 16, 2007 at 2:17 PM
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SERVICE WRITER
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HAve you performed any carbon removal procedures yet?
Jun 16, 2007 at 6:55 PM
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LRMANTE
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Thank you for responding.

No I have not performed carbon removal procedures. This problem happened suddenly. I did buy a scan tool and checked the data. I find that the MAT and MAP are reading high. The vacuum hoses have all been replaced. I did replace the O2 sensor since its been 17 yrs. I have the shop manuals to go by and am now going to test the MAP sensor and wiring. any other suggestions is appreciated.
Jun 20, 2007 at 7:22 PM
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SERVICE WRITER
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is the 8th digit of the vin an "J"?
Jun 21, 2007 at 7:41 AM
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LRMANTE
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no its an 8, it is not a ZR1.

LM
Jun 23, 2007 at 7:23 PM
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STRAIGHT AHEAD
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Best guess. Did you modify the wire loom in the car by adding a radio? Alarm system. Or by the previous owner? If you are showing a dash fault? That will tell me there is a link to your problem. The ECM is corrupt. It is a wiring problem. Next problem is exhaust system is clogged. By broken cats. Good Luck
Jul 22, 2007 at 11:31 PM
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GWH
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[quote:44bdc66efe="lrmante"]I have a 1990 corvette with 104000 miles that starts up nicely. Its a V8 stick. But as soon as it is warmed up the engine starts to sputter and trys to stall. It stays running but with stalling tendencies. The plugs, distributor, ignition module and plug wires are new. I opened the air intake plenum to ensure it was not a clogged air filter. The fuel pump was replaced last year. I reseated the ECM connectors. There are no fault codes reported just 12. No check engine light either. The SYS indicator has been flashing for years but never of any consequence. I read that is probably due to contacts in the control panel making poor connections. Please advise[/quote:44bdc66efe]



Check your EGR valve for carbon?
GWH
Aug 15, 2007 at 3:29 AM