I took a look at a friends 90 Vette and Im stumped....

the car cranks but wont fire. it worked fine and then he washed it, and now all it does is crank.

I check the pass key, ignition (volts to coil but nothing to plugs).

Im looking for a little advice before i start spending this guys money.

Thanks
Tom

 

Ttt.....

 

Hmmm
Worked fine before wash, Check under dist. cap make sure it is dry mine did that at the carwash one fine day.
Steve

 

Did he wash the engine bay?

Check under the distributor cap for water. Even if he didn't spray any water near it, water can condense there from other places.

Check for spark at whatever plug wire is easiest to reach.

Do you get any codes?

Rotation, compression, spark, fuel, and air are what you need to start.

So it seems like you have rotation.
I do not think compression got below 90 PSI between starting it and washing it and now.

Check spark!
Check fuel pressure. Does the FP run for about a second when the key is switched from off to run? (not start!)
You should be able to get a squirt of fuel at the shreder valve on the rail even if you don't have a FP gague. If it squirts, then move on to the next test for now.

Is there anything blocking the intake? Remove the filter for testing only and don't run the car without it for more than a quick test.

Is the throttle position sensor working? Have you tried starting at no throttle, 1/2 throttle and WOT?

Is there any way that water could have gotten into the fuel? Drain a bit out at the filter and in a clear container the water will seperate to the bottom.

Post back what you find.

A can of eletrical contact cleaner is cheap. Disco every connector you find and squirt it well with the contact cleaner. Allow them to air dry then reconnect.

 

If he sprayed the engine bay, check for the EST wire or the battery wire on the Distributor and make sure they weren't knocked loose.

 

The two wires are red and brown fwiw.

 

as this is the first place I would look for such a problem. You probably have either an ignition or fuel delivery problem. The ignition is the easiest to check......so do this first.