THE RACE SHOP

Hello, Ok here is what I got. I have a 5.3 with cnc 5.3 heads, cam (can get specs if needed) Carb intake, e85 carb and msd 6010. The problem im having is it appears to only be running on 4 cylinders. If I let car run cylinders 1,3,2,6 header tube is cold. Also car is very lazy and if you try to put on 2 step it will backfire out carb. Now things I have checked/replaced. I no it is not the carb as I have put on another car and also tried 2 different carbs on it. I have tried a new 6010, new coils, new crank sensor, new plugs,new wires. All clinders have 160 psi of compression. I have backed rocker arms off because I thought maybe pushrods were holding vlaves open and no change. Tried my own timing curve 32 deg straight across and msd pills. I really dont know what else to check. If you have any ideas it would be greatly appricated.

Thanks
Matt

Pop N Wood

iTrader: (1)

Are you getting spark in the cold cylinders?

THE RACE SHOP

Yes it has spark If you take plug wire off and put a plug in wire and ground plug. but when you pull the plug out it is wet as if it is not firing.

Plumbers56

Shot in the dark here, possible bad cam sensor? since they are very temperamental. Throwing your timing out of wack.

Blue Knight

iTrader: (4)

Are the installed plugs clean? Fouled?

Pop N Wood

iTrader: (1)

What voltage are you getting to the box? Also on the power wire to the coil pack?

Any chance your harness got screwed up throwing off the timing order?

THE RACE SHOP

I was told that the cam sensor was only used for startup? But I may be wrong


I have put to Brand new set of plugs in it.


Msd had 12 volts. I took ground and 12 volt wire and ran them straight to battery to bypass and switch 12 volt and bad ground.


I am now going to put motor at top dead center and marking balancer and making a pointer to verify timing in laptop is actual timing in engine.


Thanks for the responses any other information will be greatly appreciated


Thanks
Matt

Pop N Wood

iTrader: (1)

That's correct. You can unplug it and have a 50-50 chance of it starting correctly.

6.0 1955

iTrader: (20)

Any resolution to your issues? Currently having the same ptoblem on a carbd 5.3 with msd box. Thanks

ridnhood

Another shot in the dark, I remember when I had the ls2in last year the cam sensor is in the front. I just picked up a newer 5.3 w sensor in front. Had to switch two wires going to cam sensor don't remember why or what colors. If sensor is in the back, no worries. May be worth checking.

stevecritt

iTrader: (3)

I know this sounds like the most obvious, But is there any way you have the msd coil wire backwards? lol just asking bc when i quickly installed mine i did them backwards.