96 Tahoe help!!!

[Bigsand1985]

Hello everyone, this is my first post!

I have a Chevy Tahoe 1996 vortec 5.7 high miles! I have replaced the fuel pump, fuel filter, Maf sensor, air filter(k&n), spark plugs and wires, cam shaft position sensor, rotor and cap, spider assembly. All within a few days. I just finished with the spider assembly and now it runs like crap. Misfires like hell, random misfire code shown with a blinking CEL. I have read a lot of other pages and hope someone can help me. I've dropped a significant amount of money already and hope I don't have to spend much more. Help!!!

[jamesslcx]

Bigsand1985, how many miles is high miles? At what temp does it misfire? Have you figured out anything yet?

[Bigsand1985]

Originally Posted by jamesslcx

Bigsand1985, how many miles is high miles? At what temp does it misfire? Have you figured out anything yet?

Not sure if it's a misfire or not. Got it running, coil was bad. Still feels like it sputters. Happens at all temps and mostly at low speeds. Misfires at times when I let off the gas.

[FishFind]

check for play in your distributor, Wiggle it left to right. should move less then 1/8 inch.

Mine had the same issue and it ended up being the gears on the bottom of the distributor have worn and when I put the new cap on it was not lining up at the correct time.

If yo do have play you can test if it is the gears by taking the screws that hold the distributor off and twisting the whole distributor cap clockwise while running.

[Bigsand1985]

Originally Posted by Bigsand1985

Not sure if it's a misfire or not. Got it running, coil was bad. Still feels like it sputters. Happens at all temps and mostly at low speeds. Misfires at times when I let off the gas.

I mend backfires at times when I let Off the gas. And it's a 96 with 238,000 miles. Thanks.

[Bigsand1985]

Ok I'll check it. I just had the truck in the shop and the cap was replaced. I'll let you know what I find. Thanks!

[jamesslcx]

Bigsand1985 have you checked for vacuum leaks? Checked compression?

[joemffields]

you should also have test for exhaust gases leaking into the radiator

[Bigsand1985]

Good compression, vacuum system is good. Both were recently tested. I have not had the chance to test the gears on the dis. I can however move it either direction about an eight of an inch. Should it move at all of should it be completely stationary. Thanks guys for the help, as soon as I can get in there and test the gears I will let you know.

[FishFind]

so you have 1/4 inch play. that is close to say. You can leave the screws out of the cap and twist the cap and wires a little counter clock wise. If you had missfire at idle then you should be able to tell if this is your problem by doing that. If it is your problem you will the engine smooth out when it is lined up correct.

[Bigsand1985]

Okay, ill take the screws off tomorrow and let you know what i find. Thanks for the descriptive fix!!!

[j cAT]

Originally Posted by Bigsand1985

Okay, ill take the screws off tomorrow and let you know what i find. Thanks for the descriptive fix!!!

you changed alot of ignition parts. so this was miss firing which is why you dii replace all this stuff????

you say the ignition coil was bad. if so the ICM can be damaged very easy especially if original.

Ignition Control Module ...................

[777stickman]

Originally Posted by Bigsand1985

Good compression, vacuum system is good. Both were recently tested. I have not had the chance to test the gears on the dis. I can however move it either direction about an eight of an inch. Should it move at all of should it be completely stationary. Thanks guys for the help, as soon as I can get in there and test the gears I will let you know.

Service manual says no rotational play allowed when turning the rotor by hand.

[Bigsand1985]

The ICM is good, replaced, almost brand new. Coil seems to be fine, now I think the alternator is going out, making a wining noise. Check engine light came back on, solid, not flashing. I'm going to advance today to get the codes read. Will post again soon, thanks!

[j cAT]

Originally Posted by Bigsand1985

The ICM is good, replaced, almost brand new. Coil seems to be fine, now I think the alternator is going out, making a wining noise. Check engine light came back on, solid, not flashing. I'm going to advance today to get the codes read. Will post again soon, thanks!

most auto zone's can test the ICM. they have a wells tester.

remove alternator belt check bearings. check voltage out should be a solid 14volt at normal operating temp. higher at cold start.

noise can be the power steering pump. if so replace this fluid.