wont start check no spark changed cap,rotor,coil,module,crank sensor still no spark,have power at coil before problem truck was running fine then spudded and died

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 test 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 other tests are passed. then perform a complete compression test and record the results. All cylinders should be over 120lbs in most cases and all be within 10% of each other.

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




78 Corvette Pace Car For Sale-18k mi orig-Florida

i am getting fuel,i am not getting spark i have power at the coil i check spark at the spark plug wire and coil nothing

How did you determine you have fuel?

Are the plugs fouling?

Have you tested compression?

Have you verified that the distributor is actually turning?




78 Corvette Pace Car For Sale-18k mi orig-Florida




(This post was edited by Hammer Time on Nov 8, 2009, 10:24 AM)

i check by thefuel rail for fuel have fuel no spark at plugsor wires

Are you ignoring the other things I asked?




78 Corvette Pace Car For Sale-18k mi orig-Florida

the dist is turning

the dist is turning,the plugs are good but wont start no spark pulled wire on plug no spark

Paul; HT's list is the correct way to determine the cause. Was this running fine before it sputtered and died? How did the distributor cap and rotor look? You did remember to reinstall the rotor, right? Firing order correct? Fuel pressure needs to be around 55psi for this Vortec to fire. We can't be of much help until we get the results of the tests that have been made. Any trouble codes stored?
Loren
SW Washington