Coolhndluke

I have 90 gmc sierra k1500 5.7.
Recently replaced fuel pump, fuel filter, distributor and cap, coolant sensor, plugs and wires Got it al in time. Started it and drove around doing errands then it backfired, sputtered an died. Tried to restart it and sounded
like it wants to start but won't. Tried adejusting the time to start but just wont start. Back track alittle.
The reason why I replaced all those parts I mentioned before because they all either failed or part of a tune up. Failed as the fuel pump went out The distributor cap was bad so replaced the whole distributor oh and the electronic spark control too. Could the timing chain or belt be the issue? The truck is 30 years old and i only had to replace the tranny, starter, alternator and the radiator in this truck. 337,172 miles on it. I think her age is catching up with her so to speak.lol.

oilcanhenry

Can you find someone with an OBD I scan tool? If you decide to change the timing chain, get a Cloyes. The stock Chevy chain is a good chain but everything wears out at 32 years.

Coolhndluke

I have a scantool but its not showing any codes.

oilcanhenry

Are you sure you installed the distributor correctly? Are you using an OBD II scan tool, or OBD I?

Coolhndluke

So the timing chain had alot of slack in it. Replaced it and installed it according to the manual. I made a tdc whistle so I know when it's at tdc. Adjusted the distributor so as to point to the number one cylinder. Put cap on .installed plugs. Checked and rechecked to make sure they are in the correct order. Go to start it . No start. It sounds like it wants to start it never does. When I press on the gas a little air or something comes out they tbI. Fuel possibly. retard the time.no change.advance time no change. I did a compression check but not to sure on how to interpret them. The internet was unclear also.iwill post the results if somebody can explain it to me please

Coolhndluke

If you insert a screwdriver into the hole where the distributor goes and turn the slotted head. besides having to align it with the distributor does it matter how many times it's been turned

hanky

That slotted piece is to the oil pump which the dist drives.

oilcanhenry

It all comes down to ignition or fuel, barring issues like piston or valve issues, so either your timing is off or you are not getting fuel. Please do post your compression test values.

BTW, did you only do dry values, or did you add oil values as well?

Coolhndluke

I did both.

oilcanhenry

Looks really good except cylinder #8 but with over 300000 miles, that's to be expected as normal even if it's over the 15% difference line between cylinders. #8 looks close at 130 PSI dry, however, but 110 PSI is too low.

They make additives that MIGHT help, if you have carboned up piston rings, in case that's an issue. But It's hit or miss with those cleaners. Sometimes they work well, sometimes they don't. Carbon is very hard, so some have you pour down the cylinder and let it soak in, before you run it. If I did that, I'd change the motor oil not long after to get all the sludge and carbon out of the engine.Even ACDelco sells a top end cleaner.