comp cam problem


Active Member
Mar 8, 2005
A friend of mine here locally just put a comp cam 206/206 cam in his 87 GN. Stock bottom end car with some mild headwork. He replaced the stock cam b/c it wiped a lobe.
Couldn't ever get the car restarted, flooded out. Finally got it started and when it's running it sputters and backfires and won't rev worth anything. Acts really sluggish to rev.
The car has new valve springs in it.
Any ideas?
stock ecm...Lubrant chip for a stock cam 42.5 injectors...44e turbo.
You think a chip could throw it that far out? I didn't think that cam was that aggressive.
they used that cam sensor setting tool...I guess caspers with the LED's...lit up when it was ready to roll.
(I called him after ya'll posted...I'm relaying what he said)
It could still be 180 out. The sensor tool lets you set it at the correct location but you need to have it on the compression stroke and not the exhaust stroke when you set it..
It may be a good idea to make sure the ground to the turbo bracket was reinstalled correctly as well. You don't have to remove it for the install, but sometimes people do.
You can unplug cam sensor to put it into batch mode to see if it runs better/same. If it runs better in batch mode, sensor is way off. Also check PROM pins are contacting properly... i keep telling ppl this b/c it took me forever to find out why my car was pig rich.

You need to verify that you are on the compression stroke. Watch to see that the intake valve on #1 opens and closes, then be sure your at the correct mark on the damper. Still think the sensor is off. Check everything that Phil suggested. Did he degree ( phase in he cam )? Seen timing gears off by quite a few degreees, and I never trust the marks. Brian
I'll be in touch with the guy today...thanks for everything guys! This is one of the best/helpful/friendly forums out there.
Hi grocerygetter: If every suggestion given so far does not locate the problem
I would take a look at the lifter preload.I would also look at possible vac. leaks
such as the intake gasket, egr gasket,hoses etc. I hope you find the problem.
I put the 206-206 in my car and it runs fine. No excessive lope and revs good and smooth. The sputtering and back fire sounds like a timing problem. Did he get the timing gear a tooth off or is it an adjustable gear with the timing advanced/retarded? Definitely check the cam sensor.
You said that he had some head work. Was that done prior to this? If it was done while still running the stock cam that may be what wiped the lobes. I think that was what got mine. I had head work done where the guy was just going to clean up the head surface and he ended up taking enough off that I had too much preload. I didn't check when I put it back together and got about 8,000 miles (actually much less but I refused to admit that it was the problem) before the lobes wiped. The thing idled rough but ran fine. I thought it was just the cam but it was the preload. When I put this 206 in it I checked the lifter preload and ended up having to put a lot shorter pushrod in it. Idles smooth now. Point is, be safe, check preload anyway.
Sounds like the valves are hanging open. Is the cam a roller or flat tappet? If roller and roller lifters the pushrods may be a touch too long and when the lifters pump up it will hang the valves open some making it run crappy. Just one valve doing this will make it run very noticably poor at idle and will die when you put it in gear. Double check the cam sensor first since it's easier and quicker to check, then check the valve train which is what it sounds like to me.
grocerygetter said:
problem solved...timing problem. fixed now and idles great. thanks for the help guys!
Goopd to hear.
Was the camshaft, ignition, cam sensor/injection timing?