Seems like the only time I've really had problems with my '97 B2500 V6 it's with the ignition.

I only use the van once every few weeks and usually it starts right up. A few weeks back i went to use it and the engine would crank and crank...but not start.

Here's what I've checked and changed:

-checked fuel pressure at fuel rail, it charges up instantly to about 45psi and will stay that way for at least an hour after you shut off the key.
-checked spark at distributor cap center terminal...no spark.
-checked voltage at coil with key in "on" position, 11V (my battery is down a bit from cranking)
-changed coil out with new coil...still no spark at distributor
-checked Crank Position Sensor and found one of it's wires had rubbed bare on fuel rail. No signs of arcing though. Taped up insulation and tried again...still no spark at distributor.
-changed Crank Position Sensor out with a used one I had (believed to be good)...still no spark at distributor
-changed out ECU unit with my spare ECU (believed to be good)...still no spark at distributor (put original ECU back in)

I'm stumped....any suggestions?

 

1. When checking the voltage at the coil, are you checking to ground or across both terminals?

2. Did you check for spark at the coil instead of the distributor in case the coil main wire is no good?

 

1) I checked each pin on the wire to the coil against ground. One had no voltage, the other had the 11v.

2) I thought about that and tried to check the resistance in the coil lead to see if the wire was OK, but I have no idea on what it should be. How would I check the spark right at the coil? I'd need to run that pin close to ground somehow...maybe with another wire wrapped around it?...or wouldn't that give me a zap?

 

borrow a known good ECU

 

Check across both coil leads, not to ground. Check with the key on engine off and while cranking to see what you get in each case.

To check for spark at the coil you can use any piece of wire. Strip one end and stick in in the high voltage output on the coil and put the other end near the block. Set it up so the wire ends stay in place by themselves. I do not recommend you holding the wire. Once the wire is in place have someone crank the engine while you look for spark.

 

Kind of sucks doing this stuff after work in the dark...

Connected a jumper cable to the top terminal of the coil, clamped the other end onto a piece of wooden doweling, held it near the block and cranked engine to check for spark...nothing.

Checking across coil leads, with key off 0V. With key in "ON" position 11.75V, while cranking 10.8V. (My battery is still down on charge a bit I guess.)

 

The volt reads are spot on, so you're looking at a bad crank sensor or it's wiring, or the ECM.

 

TSB 08-21-97

No Start - Engine Failed To Crank

See if there is a loose connection at the starter. The van may crank, but the power may not be strong.

 

Well...having already swapped out the CPS and ECM (mind you they were both used and I have no guarantee either was good) I'm suspecting wiring...which is like finding a needle in a haystack.

Guess I'll try a new CPS first to eliminate that.

 

go back and check out the coil ;-)

You should have a voltage at the distributor cap coming from the coil. which means that the connector on the 12V side is not making a proper connection thus not working.