Van won't start, I need help figuring out why... here are the clues:

Wayne W. wrote in alt.autos.gm

A little more information would help. What year is it? Is it fuel injected, or does it have a carburater? What size engine is it? Does the engine turn over at all? If it does, does it turn over slowly or at the normal speed? And what do you mean by the plugs getting fouled? Are the wet with gasoline? Or are they covered in oil? The more we know, the better able we can help you.

If the engine does not turn over, then it is probably seized. If it does turn over, then you probably are not getting spark. Which could be caused by any number of things, depending upon how old the truck is.

The battery draining will happen when you keep cranking the engine, or if the engine is seized.

Thanks Dick,

Is that enough info?

Oops, forgot the last question about how it turns over... It turns over fast to start with, but rapidly turns slow as the battery drains. (brand new battery)

Sounds like timing. Did this happen after you replaced everything or before?

Before and after. I have been told it could be one or more of the following things on another NG:

1. Pitted contacts on Fuel-control/ECU/Ignitor relays.
2. Cold-start injector staying on when it should not.
3. Water Temperature sensor out-of-calibration. (Usually caused by corrosion on the connector.)
4. Bad Mass-airflow sensor. (Backfires commonly take these out.)
5. Fuel-pressure regulator set too high.
6. Bad oxygen sensor (not usually relevant during start-cranking).
7. Bad ECU (fuel-injection-computer)
8. And a whole raft of other niggly-little-bump-in-the-night things that are nightmarishly difficult to find.
9. If you have HEI ignition, replace the ignition module in the distributor.

Sounds liek it's randomly firing, then - basically either a shot sensor somewhere or something in the timing gear.

Q: if you try to start it, does it every so often almost start?

Turns over - check. Plugs fire - check. Fuel is working - check. That leaves timing as an obvious culprit. The MAF if it has one is also likely shot due to age and these problems being hard on it.

I am also suspecting the MAF. I will check that out this morning.

Thanks for the feedback.

Wayne

From what I've read I gather you've checked and you have spark and fuel have you checked compression? Like mentioned your timing chain could have jumped.

Even if a sensor is faulty typically it will go in to limp mode and still run.

Wayne W. wrote in alt.autos.gm

You're welcome. It does seem to have helped, by the number of replies you have received.

If by scorched, you mean that they turn white? If so, then you are not getting fuel. Could be fuel filter or fuel pump, or related wiring. Does the fuel pump turn on when you first turn on the key? Another thing it could be is the timing is off, with the engine at top dead center, according to the timing marks, does the rotor point at the spark plug wire for number 1 cylinder? If it points directly away from from the number one spot, then crank the engine one revolution and check again. If it does not point at #1 when at TDC then your timing chain has probably jumped a tooth. There are many things that could be wrong here, most of them easy to fix. As we make suggestions, check them out, and let us know what you find.

I think I tracked the problem down, but am not saying yet, as I don't want to jinx it.

Wayne