84 Crossfire "Backfire"
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Intermediate
Joined: Jun 2006
Posts: 44
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From: Bristol VA
84 Crossfire "Backfire"
I bought an 84 about a year ago that hadn't been started in 2 yrs. Basically just sitting outside deteriorating. The gas tank was actually full of water. Anyway, I replaced an injector and got it running. The car needs a total cosmetic restoration so I'm trying to start it every couple of weeks to keep it running til I can start the restore. Now, for the problem. From the time I replaced the injector and got it started, every time I start it, it would run really rough until it warmed up and it would smooth out and idle fine. Now it has started to backfire thru the carb (injectors) and really won't smooth out at all. I know this is very little info. but if anyone has any ideas of the minimum I can do to keep it in running order I would greatly appreciate your input. The backfiring has me concerned. Also, I believe the previous owner remove the thermostat and didn't put one back.
Thanks for your time.
Bryan
Thanks for your time.
Bryan
Pro
Joined: Dec 2002
Posts: 603
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From: 84 383 XFire Chandler, AZ
The cold start issue will more than likely be fixed by replacing the CTS (coolant temp sensor) in the front of the manifold. A typical symptom of a bad CTS is rough idle when cold and then runs well when warm. I would first suspect the fuel pump because you said the tank was full of water.
Are there any codes? eg blinking Check Engine Light.
Are there any codes? eg blinking Check Engine Light.
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Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Check codes first and repair them properly, by trouble shooting before you do anything else. The CTS CAN cause the problems described, but it should be tested before condemned. The fuel pump can be tested too. There is no reason to throw money at it.
RACE ON!!!
RACE ON!!!
Thread Starter
Intermediate
Joined: Jun 2006
Posts: 44
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From: Bristol VA
Actually the check engine light just started coming on. The digital dash is pretty much shot and the gauges are suspect since its been sitting so long. What do you think could be causing the "backfire" from the throttle bodies. Thats where it sounds like its coming from. Do you use one of the diagnostics testers to pull codes? I was thinking that the local auto parts said theres didn't go back that far. Thanks for any more suggestions.
Bryan
Bryan
Advanced
Joined: Aug 2002
Posts: 99
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From: PA
Actually the check engine light just started coming on. The digital dash is pretty much shot and the gauges are suspect since its been sitting so long. What do you think could be causing the "backfire" from the throttle bodies. Thats where it sounds like its coming from. Do you use one of the diagnostics testers to pull codes? I was thinking that the local auto parts said theres didn't go back that far. Thanks for any more suggestions.
Bryan
Bryan
Thread Starter
Intermediate
Joined: Jun 2006
Posts: 44
Likes: 1
From: Bristol VA
Yes, I do have a service manual. I realize its very hard to diagnose something like this with such limited information. The car has really sat for about 10 years with very limited running and since I've actually got it running I hate to let it start "sitting" for another year. I appreciate this forum and the wealth of information available here.
Bryan
Bryan
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
The service manual tells you how to pull codes with no tools or "readers". Once you have the codes it will tell you what system or circuit the code came in on, what conditions will set a code on that circuit and provide a trouble shooting chart to find the cause of the code. Don't assume that a code labeled "EGR" means the EGR valve is bad. The EGR valve, itself, is seldom the cause of an EGR code. Therefore, don't blindly throw parts at the problem. Diagnose the cause and test anything you can before replacing it.
RACE ON!!!
RACE ON!!!
