x2 on checking the timing :-X22

Also, flooding could very well have caused it so I would look into that as well. That was a good suggestion.

Try to knock out all those tests today and give us the results. This one has got me thinking.

Ok I checked the timing again by taking out #1 plug and had someone bump the key till I found tdc compression. Checked the rotor, just barely off #1 terminal so I turned the dizzy a little to get it right on. Also the harmonic balancer is on 0°. I looked into the spark plug hole with a flashlight and I can see the top of the piston, right up to the hole.

I bought a new fuel pressure gauge yesterday, hooked it up and I'm getting 36 psi, then after a few minutes or so it went down to 30 psi. Does this sound acceptable?

Tanner

Bump.

Tanner

Me and my uncle checked the timing with a light while cranking with the spout out, it was off but turned the distributor a little bit and got it right on. What could cause a truck to not start when it has good fuel pressure, good spark, and correct timing? This isn't making sense to me...

Tanner

That's got me thinking it's something electrical..

I though fuel pressure should be closer to 50-60 psi on fuel injection for this model of pickup.

That's what its coming down to...unfortunately I am not good with anything electrical. Any clue what might be bad? I'm still thinking its ignition related because it won't run on starting fluid.

Tanner

I believe for an I6 the fuel pressure is in that range but the v8's are lower.

Tanner

Well, you better get good at it pretty quickly if you want to get your truck running.

The primary factor here is that you had to remove the distributor to do this job.

You say that you have good spark... okay, do you have good spark at the right time? I'm gonna say no, because otherwise you should at least be getting a sputter/attempt to start if you're using starter fluid. In this case, 1 of 3 primary problems are happening:

1) The timing is off and you aren't getting spark at the right time.
2) There's no fuel in the combustion chamber.
3) There's not enough air getting to the combustion chamber (even if this were the case, starting fluid is volatile enough that it should still fire).

If the mechanical timing is correctly aligned on the distributor, I suspect that you've got the spark plug wires hooked up wrong. Double check them.


https://cimg5.ibsrv.net/gimg/www.for...e8c181de43.gif

He said earlier in the thread that he's already confirmed the truck has correct timing. Worth checking the firing order again, though.

Thanks guys. The sticker under my hood says the firing order is 1-5-4-2-6-3-7-8. I'll double check everything again.

Tanner

Yes that is your right firing order, 1-5-4-2-6-3-7-8 for a 1990 5.0L.

Alright, checked the firing order again..its correct. I put in a new distributor and ICM as well, the cap that came with it has #1 marked so I know that's good. I don't like throwing parts at a vehicle but at this point I don't know what else to do.

It seems to turn over at normal speed so I don't think my timing chain jumped a tooth or something and lost compression.

Tanner

Out of curiosity, did you pull the #1 spark plug out? Was it wet? You said you checked the fuel rail but did you check to see if the injectors were opening and letting fuel into the cyl? I'm almost thinking you have a bad PCM.

A quick test to determine if the PCM is at fault, most likely, or the Fuel Pump Relay is stuck in the On position is to disconnect the PCM then cycle the key On. If the pump turns on then you have a bad relay. If the fuel pump does not turn on then you have a bad PCM. Hope it helps.

Thanks mike, I'll have to try that and see if my PCM is bad.

I just read a thread where a guy had a similar problem. He found out his coil was bad. I replaced my coil a few months ago with an MSD blaster, but I kept the original one. I'll swap it over and see what happens.

Tanner