Engine wont start

[jcfreeman0]

I've got a 4.8l engine in my project truck. I just finished wiring it back up Friday and it fired right up. I started it for about 30 seconds maybe 4 times on Saturday. It now will not start. It will crank and every now and then a partial fire but will not run. I added some new fuel to my fuel cell because what was in there was kind of old (last sept). This has been a cab off build and i just put the cab on the other day. Its got me confused because it was running and now will not. Its show fuel pressure on the gauge (around 60) and i can hear the external pump working.

Last year i but a cam, headers, ls1 intake manifold, blackbear tune, exhaust, slp valve springs etc and had it running. Then tore it apart and now trying to get it back together. Please help if you have any ideas / suggestions!

[flattopwill]

Running open headers?

Check the plugs. I had a similar problem where the truck was running very rich and we ran it a few times trying to diagnose the problem meanwhile the plugs got fouled bad. When we finally figured out what the problem was it wouldnt start cause the plugs were so bad. May not be the problem but its somewhere to start.

[jcfreeman0]

I pulled a plug this morning and noticed its a little bit wet and has some black crud build up on it. I'm gonna pull all the plugs and clean them off this evening. Hopefully this helps!

Also i noticed the MAP sensor was broke yesterday. I had another one laying around and put it in but it still wouldnt fire.

[Venom]

i was gonna say plugs. also is ur intake from ur throttle body to ur air filter hooked up? ive seem people try do a swap or work on their vehicle and they want to see if it runs and dont put the intake tube on and it wont because its not on. its gotta read the MAF.

[jcfreeman0]

i was gonna say plugs. also is ur intake from ur throttle body to ur air filter hooked up? ive seem people try do a swap or work on their vehicle and they want to see if it runs and dont put the intake tube on and it wont because its not on. its gotta read the MAF.

Yeah its on.

I pulled all the plugs out tonight and cleaned them up a little bit and put them all back in and it "almost" starts. It fires about every other try but wont actually start. I ordered some new NGK's today (wont be in until tomorrow) so hopefully the new plugs will solve my problem.

[jcfreeman0]

SHES ALIVE!!! I put the new NGK's in and it started up on the first fire! Thanks for all the help guys!!!

[flattopwill]

Hell yeah. Called it.

[jcfreeman0]

Hell yeah. Called it.

haha yep sure did. Thanks man!

[truckinL33]

This is great success! Love seening things work out that fast! Good job guys!

[Clyde65]

I had that issue too, you might want to see what messed up the orig injectors, I found rust in the fuel rail, switched that and injectors and all is well on mine too. Congrats, it feels good when you find the problem.