96 Tahoe Won't Start

[NEW2MALIBU]

Sorry....First post is gonna be a mechanical question. My wife's 96 Tahoe. 175,000 miles. 5.7L Bought this used, Have already done some of the majors fixes: Lower Intake Manifold Gasket, SFI Spider, Fuel Pump and new Trans. Recent tune up: plugs, wires, cap, rotor, fuel filter.
My problem is: this morning my wife went to start the truck. It try's to start, but won't. Spins over good, then starts turning slow and jumping around like the timing chain has jumped a tooth, then repeats. It did this about 3 weeks ago for the first time, but eventually it started. This is the third time in 3 weeks, but the first time it will not start. The CEL is on, codes are PO420 and PO430. I know that is the cat codes but exhaust seems clear and no driveability issues when it is running.
Thanks in advance for the help.

 

[96ProCompTahoe]

pull the distributor cap back off and see if its corroded and arching.

bad design on the cap where it doesn't seal to the distributor. have to clean mine couple times a year, does the same thing you are describing but without the SES light

 

[NEW2MALIBU]

Right on. I will check it. CEL was on before this issue ever came up.
Thanks for the quick response. I will let you know how it turns out.

---------- Post added at 10:33 PM ---------- Previous post was at 09:54 PM ----------

96 Pro Comp. You are the man. Cleaned it up and it fired right off. I can't thank you enough.
Mitch

 

[SunlitComet]

Those codes reflect TWC Converter System Low Efficiency Banks 1 and 2. Your Post converter sensors are reporting that the emissions are to close to what is being seeing before entry into the converter. It could be a timing, ignition firing or you can be burning something other then fuel in there that is effecting them or they could be worn out. The no start might be the cap like procomp mentioned but if it still won't start look for code history or the possibility of obstruction in the exhuast some where. Seen anything odd around on the ground near your tailpipe lately? If you want specific diagnosis procedures for those codes answer back. Burning fluids, timing and misfire are some of the causes.

---------- Post added at 09:53 PM ---------- Previous post was at 09:52 PM ----------

[/COLOR]96 Pro Comp. You are the man. Cleaned it up and it fired right off. I can't thank you enough.
Mitch[/QUOTE]

Corious, did it wipe out your codes?

 

[96ProCompTahoe]

96 Pro Comp. You are the man. Cleaned it up and it fired right off. I can't thank you enough.
Mitch

your welcome glad to here it was a simple fix! and welcome to the forum!