I'm Stumped.....Any ideas?
Thread Starter
TECH Fanatic
Joined: Oct 2011
Posts: 1,425
Likes: 0
I'm Stumped.....Any ideas? Last week I made some brackets to re-locate my coils while I was swapping from the Vic Jr. Intake to a Pro Flo XT. I got a coil wire backwards and the car back fired when I tried to start it. It never was running yet.
The next time I tried to start it, the starter sounded like it was just spinning. The engine didn't SOUND like it was turning over. I replaced the starter thinking the starter was toast but the same thing happened. I had a friend come over to see what was going on. He said the motor was turning over from the starter but it sure didn't sound like it. So now I figured I popped the timing chain from the backfire and pull the engine and figure I will clean it up while its out. I don't know why I didn't do this first but when I pulled the valve covers and turned the engine over by hand, all the rockers, etc. was working like they are supposed to. WTF? Tomorrow I will be renting a puller to pull the balancer and will swap the timing chain anyways with my LS2 chain I have
So my question is: If the starter is turning the engine and the timing chain isn't broken, why is the engine just spinning and not "firing?" I also tried this with the plugs pulled and the injectors un hooked and it still did the same thing. My buddy thinks the timing chain might have slipped a tooth but I would have thought it would still try and "fire up" not just sound like the starter was spinning.
Sorry for the long post.
The car was running just fine prior to me swapping the intakes and relocating wires.
The next time I tried to start it, the starter sounded like it was just spinning. The engine didn't SOUND like it was turning over. I replaced the starter thinking the starter was toast but the same thing happened. I had a friend come over to see what was going on. He said the motor was turning over from the starter but it sure didn't sound like it. So now I figured I popped the timing chain from the backfire and pull the engine and figure I will clean it up while its out. I don't know why I didn't do this first but when I pulled the valve covers and turned the engine over by hand, all the rockers, etc. was working like they are supposed to. WTF? Tomorrow I will be renting a puller to pull the balancer and will swap the timing chain anyways with my LS2 chain I have
So my question is: If the starter is turning the engine and the timing chain isn't broken, why is the engine just spinning and not "firing?" I also tried this with the plugs pulled and the injectors un hooked and it still did the same thing. My buddy thinks the timing chain might have slipped a tooth but I would have thought it would still try and "fire up" not just sound like the starter was spinning.
Sorry for the long post.
The car was running just fine prior to me swapping the intakes and relocating wires.
I doubt you "jumped a tooth" I also doubt that a backfire hurt anything. I bet you somehow washed the cylinders and now is just spinning over without compression. Were the plugs wet when you pulled them? Do a compression check. Put a finger in a spark plug hole and crank it over, does it blow it out? I would do all these checks before I pull it out. Check the oil level, is it over filled?
Thread Starter
TECH Fanatic
Joined: Oct 2011
Posts: 1,425
Likes: 0
Thanks for the responses. I could have pinched the wire but it did this also before I changed starters so don't think it was that. My oil level was not over filled. Oil looked good when I drained it. I do have air blowing out each cylinder when I turn it over by hand. I will pull the timing chain cover tomorrow and if it isn't a broken timing chain, it is probably because I washed the cylinders from trying to find fix my fuel leak when changing the intake out.
I'll update this tomorrow and my buddy is going to come over and do a compression test for me.
I'll update this tomorrow and my buddy is going to come over and do a compression test for me.
What do you mean by a coil wire backwards? If your saying what I think check fuses and power and grounds on that circuit, if the pcm got back fed voltage you could have damaged it.did you test spark and injector pulse as well?
Trending Topics
TECH Fanatic
Joined: Jan 2012
Posts: 1,076
Likes: 0
have you checked to see if the coils are getting power? http://www.knology.net/~rv7rotary/Wi...S1%20coils.jpg
check the wiring color this is how they should be. I bet you have the coils mixed up. does it pop and back fire when you crank it over?
check the wiring color this is how they should be. I bet you have the coils mixed up. does it pop and back fire when you crank it over?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
+1
That's what I get when reading it too. I bet it has some blown fuses/fusible links.
TECH Fanatic
Joined: Jan 2012
Posts: 1,076
Likes: 0
The individual plugs that plug into the coil if they are flipped or out of order the firing order is wrong. He probably took them off when relocating the coils under the cowl. I made the same mistake.
Thread Starter
TECH Fanatic
Joined: Oct 2011
Posts: 1,425
Likes: 0
And the winner is........Lil john. Got the timing cover off and the chain was still there but it was definitely off one tooth. The back fire must have popped it. Checked compression in all cylinders after fixing. Good thing I still had my LS chain. We popped it in and have compression. Since I had it out. Going to clean up the engine a little and smooth my valve covers, etc.. Should have it in and running in a few weeks.
Thanks all.
Thanks all.