I just put in a Gm 847 cam 1.6 RR's new lifters and pushrods. When I went to start it up initailly, the car started right up but I had to give it gas to keep it on. Well, I boke in the cam for twenty minutes and shut it down. I went to try and start it back up and it took forever to get it going. I decided that the rocckers needed to be adjusted and I even pulled of the intake to do it. When I put it back together, it didint start at all! Its on a stock tune 97 f-body. I also deleted the a.i.r and egr sytems. What the hell is wrong with this thing. I have checked the spark, good fuel pressure( plugs are fouled. My oil even smells like gas. I checked every vacumm line as well. I really need some opinions guys. I am at my wits end with this thing. I also changed out my springs to K-800's. My car is also having trouble turning itself over. My battery is kept at full charge with a charger. It is also coughing at me through the intake.

 

Take out all the plugs and clean them. Sounds like that's the problem.

Rich

 

Thanks Bud, I will try that and get back to you. All my pugs are fuel soaked and I thought it would at least try to start.

 

By "pulled off the intake", do you mean you pulled the intake manifold off (not likely), or you pulled the air inlet ducting/MAF off (not sure why you would do either to adjust the rockers)? In any case, you forgot to hook some part of the ignition system, or one of the sensors back up. Do you have spark?

Moving to LT1/LT4 Engine Tech.......

 

I pulled of the intake manifold. I heard the car backfire twice so I checked for bent pushrods, they were all lok. I am going to change the plugs today and hope it starts. WOuld it be ok to drive it with the stock tune for like a week.

 

Running crappy
Had to hold the throttle to maintain running
Back firing
Crankcase dilution
You have spark cause you said you checked it. I assume you checked all 8.
Fuel pressure is good

If that's what I read from what you posted, then one thing fits all those symptoms to a "T".

At least 2 plug wires have been connected to the wrong plugs.

Second most likely cause, plug wires are not crossed but 2 or more are not firing. And either you didn't check all 8 or it's an intermittent spark problem.

First before you do anything else. Change your oil.

Next double and triple check the plug wire connections to the correct plug. If you need it, go to SHOE's website for the cylinder markings on the opti cap.
Passenger side top to bottom is 4,6,8,2 and driver side top to bottom is 5,3,7,1.

If they're correct, determine which if any are not firing. I have headers so figuring out which is misfiring is easy with an infared thermometer. In fact had one out yesterday. Showed right up on the thermometer as soon as I fired it up. Found that one of the plug wires was just touching a bracket and started "arcing" through the insulation. It wasn't even smashed against it or even pushed up to it. Just merely touching it. But the wires were old.

If your plugs are connected correctly and you did say you can't get it started. Connect a jumper battery and this time when you crank it, hold the throttle to the floor. This will cut back the fuel and allow a flooded engine to start easier.

Don't run it long if you can help it. You can find the cylinder that is not firing other ways. Like pulling injector clips off. Or the burning method, pull a plug wire and see which doesn't have any effect on the way the engine is running.

 

I don't think the 847 likes stock PCM tuning. You shouldn't have to break in a roller cam.... Some good info provided above though.

 

I think you guys are all overshooting the simplicity of this one. he swapped the cam out, now it barely runs, plugs are fouling out, and its backfiring through the intake........incorrect installation of either the cam itself (gear syncronization) or the opti is not aligned correctly. It farts through the intake and backfires because your cam/spark timing is off. For your sake I hope im wrong, but thats my guess. Good luck and keep us posted.

 

It was already mentioned that at least 2 of the plug wires are swapped. Which will create the exact same problem. Don't think you can get much simpler than that.

I had one wire that was arcing to a bracket (again as mentioned before) and ran crappy and backfired.

 

Well guys. Thanks for all the input. I have come to a conclusion on wat I think was and is wrong with my car. Initially, I the car started right up and would not stay on unless there was someone on the pedal. I did more research and relized I put the the rockers on way to tight. I readjusted them and went to try and start it with no luck. My first mistake was leaving the fouled plugs untouched.(<---- This I am assuming is what caused it not to start). When I went to change my spark plugs out, cylinder #4 would not thread in by hand so my friend thats helping me managed to put the plug in putting his own thread in the head! So basically, I have to tear this thing down again to fix yet another stupid little nuisance. Thanks for the help guys. I will bring this thread back up when the car is done and will probably post a video as well for all the contributing members.( If i figure out how to post one that is)

 

I finally started my car today. I am actaully pulled everything apart again just to find out the opti pin was not in its hole. I fixed that and it fired right up. SO everyone who said it was timing, you hit the nail on the head. Thanks Guys