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1999 Chevrolet Tahoe Repair Question


Topics covered: Distributor, Spark, Compression.
Mileage: 110,050 miles.

Asked on March 12, 2012

1999 chevy tahoe 5.7 v8,will turn over but will not start, replaced crank sencer,distributor cap,distributor rotor, ingnition moduler, ignition coil pack,spark plug,wires are good,relay swiches strater&fuel, and replaced the fuel pump, still the samething

Will not start.
Avatar Asked by bigglou

Answer

Replied on March 12, 2012

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.

Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.

2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.

3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.

Tiny Answered by Wrenchtech (expert)
14,713 answers provided
Replied on March 12, 2012

cam sensor /hall effect/ pickup coil in distributor. have to remove and disassemble.

Tiny Answered by fixitmr
24 questions asked
Replied on March 13, 2012

I wouldn't mess with anything in the distributor at this point until you get some idea what function is preventing it from starting. If you move that distributor you will need a professional scan tool to get it set right again

Tiny Answered by Wrenchtech (expert)
14,713 answers provided

Replied on March 13, 2012

Basic diagnosing, late model vehicles give you the luxury of trouble codes. 98 and up C/Ks (Silverado,Tahoe,suburban) had a theft deterrent system that can cause this problem. Get trouble codes, or even better get a dealer to diagnose it for you. Beats guessing at parts. That way wastes time and money and worse yet you could CAUSE more problems than what you started with which again will cost more money and time for a PRO to diagnose.

Tiny Answered by tech911
0 questions asked