99 350 no start

[rlb]

Posting this for my Uncle...

He has a '99 suburban with 350. Its the "spider" fuel injection. 300,000 miles.

Was running okay. Now cranks but no start. Turns over, sounds normal, won't fire at all.

Fuel Pressure good, 60 psi when cranking
Good spark on one plug

Compressions 1, 3, 5, 7, are 100, 160, 175, 85 psi
Compressions 2, 4, 6, 8 165, 185, 120, 175

Popped and spit when sprayed with starting fluid. Obviously has one bad cylinder, but should run. Next steps? He is thinking the ECM is bad or distributor timing jumped.

 

[Will L.]

That's quite a spread in pressures there. I don't know about distributor timing jumping- I would look at timing chain having jumped. Any codes on?

I would be careful throwing any $ into a repair as opposed to a rebuild.

 

[rlb]

No codes. My guess is timing chain as well...

 

[THEFERMANATOR]

Put a new cap and rotor on it 1st before you do anything else. The vortec caps with there corrected firing order fail pretty often, and cause all kinds of misfires when they do.

 

[Will L.]

Put a new cap and rotor on it 1st before you do anything else. The vortec caps with there corrected firing order fail pretty often, and cause all kinds of misfires when they do.

When they do that, don't they usually get the p301-p308?

Good idea, can't go wrong with low cost items like that.

 

[THEFERMANATOR]

When they do that, don't they usually get the p301-p308?

Good idea, can't go wrong with low cost items like that.

Nope, when the cap goes it will normally just shut off. Or if it does start it will pop and buck, and backfire shutting itself off. I fought one for 2 days before I tried a cap, it fired right up.