Need help on diagnosing a problem
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Joined: Apr 2008
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From: Luling la
Need help on diagnosing a problem
I had my engine rebuild (it only had 48,000 miles but was knocking badly). Since it was rebuild it is difficult to start (it turns over initially and dies, then you have to keep the pedel to the floor and keep the rpm's up to keep it from dying. When driving while cold it misses badly until warmed up, then runs pretty good. Once you turn it off it is just as hard to start even after running it for 30 minutes or longer.
One suggestion was the EGR Valve Temperature Sensor. Does that make sense to you?
Thanks for your help.
Jim
One suggestion was the EGR Valve Temperature Sensor. Does that make sense to you?
Thanks for your help.
Jim
Corvette Enthusiast
Joined: Oct 2007
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From: So. Cal.
2025 C7 of the Year Finalist- Unmodified
2024 C7 of the Year Finalist - Unmodified
2023 C7 of the Year Finalist - Unmodified
missing?
Any codes? Check fuel pressure and MAF sensor. Sometimes MAF takes a dump and doesnt set a code. Unplug MAF and see if it runs better, Good luck!
Safety Car
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From: :45 minutes from everywhere / E-I-E-I-O
I had my engine rebuild (it only had 48,000 miles but was knocking badly). Since it was rebuild it is difficult to start (it turns over initially and dies, then you have to keep the pedel to the floor and keep the rpm's up to keep it from dying. When driving while cold it misses badly until warmed up, then runs pretty good. Once you turn it off it is just as hard to start even after running it for 30 minutes or longer.
One suggestion was the EGR Valve Temperature Sensor. Does that make sense to you?
Thanks for your help.
Jim
One suggestion was the EGR Valve Temperature Sensor. Does that make sense to you?
Thanks for your help.
Jim
A bad temp sensor could [mis-] inform the computer to believe the motor is still cold, and keep extra fuel goin' through the injectors. Does the gauge for temp indicate warm-up? How's the fuel mileage (this might be an indicator of heavy fuel delivery).
How's the warm-motor idle? Any loping idle? Up and down?
Safety Car
Joined: Jan 2006
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From: Mt Laurel NJ
St. Jude Donor '06-'07
What year is the car? Is the engine stock? Could be alot of things going on, do you have an Factory service Manual? They are invaluable in resolving problems like this.
When the engine first starts, do you smell gas?
When the engine first starts, do you smell gas?
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Joined: Apr 2008
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From: Luling la
Yes, Yes & Yes
Definately smell gas when the car starts up. It is a stock engine (5.7 original engine). The car is a 1989 convertible. I do have the factory service manual ( I purchased for my mechanic because it is definately out of my league, but my mechanic does not have access to the internet so I have to ask the questions).
Le Mans Master
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From: Phoenix AZ
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egr temp sensor
The EGR temp sensor is a feedback to the computer that tells it if the pipe gets hot, the egr valve opened, and the system is working.
It doesn't have much to do with running the engine, just throwing a code. If the sensor doesn't get hot, or it stays hot once the ECM calls for the EGR solenoid to shut off the vacuum to the EGR valve to allow it to close, it throws a code.
Your problem could be the distributor module, or the engine computer, or a dozen things.
Your injectors could be bad. Your fuel pump could be going bad.
You have to take fuel pressure measurements when hot, when cold, and when shut off.
You have to start somewhere, so start with th fuel pressure, then move to the electrical.
It doesn't have much to do with running the engine, just throwing a code. If the sensor doesn't get hot, or it stays hot once the ECM calls for the EGR solenoid to shut off the vacuum to the EGR valve to allow it to close, it throws a code.
Your problem could be the distributor module, or the engine computer, or a dozen things.
Your injectors could be bad. Your fuel pump could be going bad.
You have to take fuel pressure measurements when hot, when cold, and when shut off.
You have to start somewhere, so start with th fuel pressure, then move to the electrical.
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Safety Car
Joined: Oct 2007
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From: :45 minutes from everywhere / E-I-E-I-O
Your mechanic might be a great guy, and your best buddy, but without internet for Alldata.com, or Mitchell's, he's in the dark on computer-controlled cars (unless he has the CD's in his computer). That includes most cars made for the last 30 years.
