MAF & MAP Sensor Issues
Thread Starter
1st Gear
Joined: Mar 2017
Posts: 1
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MAF & MAP Sensor Issues
Good day, I have a 1985 C4 that appears to have an internal conflict between the MAF & MAP sensors. It will never throw a code but on startup it will not run properly unless I unplug the MAF before starting it and then wait a few minutes before plugging it back in. That silly ritual works but is a pain in the but.
I don't know if it is a MAF/MAP conflict or something else like a bad temp sensor or maybe a cold start relay. But what ever it is, the problem goes away once the car is warmed up.
I had to do the 9th injector delete last year. That injector was constantly dumping raw fuel into the intake. This issue was happening long before the 9th injector and continues after its delete.
Thanks
I don't know if it is a MAF/MAP conflict or something else like a bad temp sensor or maybe a cold start relay. But what ever it is, the problem goes away once the car is warmed up.
I had to do the 9th injector delete last year. That injector was constantly dumping raw fuel into the intake. This issue was happening long before the 9th injector and continues after its delete.
Thanks
Team Owner
Joined: Jul 2004
Posts: 28,463
Likes: 3,288
From: Hartford WI
Do they have both? Mine has MAP only and it is a 91. I was under the impression that it is "either or". I would wonder if the plug is weak or the prongs from the MAF are shaky which is why your unplugging works. It jiggles the contacts back. My first thing to do is to change the MAF plug. There are spare plugs out there. Cut them off and SOLDER them back. If it still continues, next thing I would try is to replace the MAF with a known good one.
If you suspect the temp sensor is bad, you need an infra red thermometer and a scanner. Read the temp via the scanner and hit it with the thermometer. They should be reasonably close.
Why is that? Why didn't you have it fixed?
If you suspect the temp sensor is bad, you need an infra red thermometer and a scanner. Read the temp via the scanner and hit it with the thermometer. They should be reasonably close.
Why is that? Why didn't you have it fixed?
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
It sounds like you had a mechanical problem with the cold start injector itself. If you want to make your car work correctly, I suggest sending it to Jon at FIC (Fuel Injector Connection). He can test it and tell you what the situation is.
