post cam/heads headach- dealership helped out
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Joined: Nov 2002
Posts: 338
From: Dayton Ohio
post cam/heads headach- dealership helped out
OK, I iinstalled a cam and had my heads ported. after I installed them I had a ruff time getting the car to idle right. After it would warm up it would have a miss and a "pop" would come out of the exhaust. Under load the car would backfire in first and second gear ( any time the rpm's get around 1000 to 1500 ) I replaced the opti, plugs, wires, coil and adjusted the valves about ten times. I couldn't narrow the problem down and was about ready to pull my hair out so I took it to the dealership today on a roll back.
It showed the same thing that I had found with the Long term fuel counts, they were 120 on the left and 160 on the right. They also put the car on a "scope" and it showed that #3 cyl. wasn't getting the right spark and that #8 wasn't getting fuel. 
We took the plug out of #3 and it was really dark and smelled like gas. We replaced that plug and stuck a noid light on #8 injector. It was getting good signal.??? I have a whole set of brand new 30# SOV's in the garage that I had on earlier. I'm going to try and adjust the valves on #8 again tomarrow before I R2 the fuel injector(s). If this doesn't work I'm lost!!!! I've programed the PCM's idle up about 100rpms and when I had the 30#ers in there I adjusted the injector constant. The cam is basically a hotcam, I shouldn't need a custom tune just to get it to run...should I? That is the only thing that I could think that the problem could be other than a valve that is getting hung up? Any ideas??? Thanks for ANY help.
It showed the same thing that I had found with the Long term fuel counts, they were 120 on the left and 160 on the right. They also put the car on a "scope" and it showed that #3 cyl. wasn't getting the right spark and that #8 wasn't getting fuel. We took the plug out of #3 and it was really dark and smelled like gas. We replaced that plug and stuck a noid light on #8 injector. It was getting good signal.??? I have a whole set of brand new 30# SOV's in the garage that I had on earlier. I'm going to try and adjust the valves on #8 again tomarrow before I R2 the fuel injector(s). If this doesn't work I'm lost!!!! I've programed the PCM's idle up about 100rpms and when I had the 30#ers in there I adjusted the injector constant. The cam is basically a hotcam, I shouldn't need a custom tune just to get it to run...should I? That is the only thing that I could think that the problem could be other than a valve that is getting hung up? Any ideas??? Thanks for ANY help.
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Joined: Jun 2001
Posts: 3,737
From: waterford, MI - USA
how positive are you the chain is on straight? as in the dots lined up? you can do a cyl. leakdown test to make sure the valves are doin what they are sealing. and a compression test to make sure the lifters are adj. properly. if they are too tight, it will hold open the valve too long, bleeding off the press. if too loose, wont open the valve all the way and also wont get high enough press. reading. take a reading from another cyl. to compare the results too. as far as the fuel trim counts, I dont think thats the prob. at all. Ive heard of that happening to alot of built LT1's and they dont have that problem(s). good luck.
chris
chris
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