BCdawg57

Well i finnaly got my lt1 to fire up for the first time. I had to start it a few times and give it some gas and eventually i got it to idle at what sounded like normal (hard to tell cause its still open headers). I did notice some smoke coming from the passenger side, it smelled like something was burning. I shut it off, looked around and didnt see anything, and i still am not sure what it was.

Fast forward to today. I try to start it, and after like 5 seconds of turning over i get a fire or 2, and if i give it gas to keep it alive i get the most horrendous backfire out of the intake ive ever heard, sounds like a gun going off repeatedly. Then it dies as soon as i let off the gas.

I did notice that my fuel rail is leaking an extremley small ammount of gas, i had a little puddle on my intake by my injectors. And my O2 wire is currently laying on my exhaust pipe on the pass side, but i have it wraped in heat resistant wrap. Source of the smoking maybe? My heater box is about 1/8th of an inch away from a header primary so that could also be the smoking. I havent looked closley at it yet so i dont know if it has burned.

Right now i am unable to scan for codes becaue i dont have a scanner, and my ses light doesnt work with the new computer. I did do the opti test though and i get a good 2-3 volt ac current on the white wire.

What could be causing my problems? It's strange because it ran fine yesterday, and now...nothing but backfires.

mrmint69

Sounds like you burnt something important. Maybe a plug wire or sensor wire. If you had grease or something on the exhaust from working on it it will smell for a while.

BCdawg57

I checked all the plug wires and they are all ok. I will crawl under there and check my o2 tomorrow. Could a fried o2 wire cause what im describing?

96' Formula WS6

are you positive the orings around the injectors were in straight when you put it back on. This would cause a big vacuum leak and possible small fuel leak. It would make for a very hard start with a vacuum leak like that.

BCdawg57

No, im not sure, but i will look it over. It is leaking out of the part where the front cross tube goes into the passenger side fuel rail. The thing is it ran fine yesterday and i havenet touched anything and now it doesnt run more than a fire or 2.

BCdawg57

Also, when i took the valve cover off to examine the rockers and springs, i could wiggle more than one rocker arm, it seemed to have way more play in it that i think it should. I adjusted the valve lash properly when i assembled the engine. Do you think the poly locks could have backed off a little and started causing my problem.

BCdawg57

Found the problem, exhaust rocker on cyl #1 came off the pushrod. simply put it back on and now starts right up.

klrz28

loose grounds will make slow to start