Intermittent crank no start?

I can pull out my bulb and replace it so does that mean I have composite?

This is awesome thank you! I will get to work with these tomorrow.

Hi Joe!

It's been a while; I hope it's still okay to reply to this thread. I've been driving my van since I last talked to you. It was running just fine until about a week ago. I've now been having the intermittent stalling and crank no start episodes again. My van is actually stuck in a grocery store parking lot right now because it just wouldn't start again after I went grocery shopping today. What I noticed today is that although my fuel pump relay is working (I can see if closing when I pop the little cover off and I hear it click, even tried multiple relays) my fuel pump is currently not getting power. I can't hear the fuel pump running when I turn my ignition to the on position, and I normally do head it prime. I replaced my fuel pump recently, so I don't think it's the fuel pump/sending unit itself. I'm guessing there must be an issue elsewhere in the circuit. I don't see any other fuses or relays that should be involved besides the fuel solenoid fuse which looks good. Do you have any ideas of things I can try to get the fuel pump running? I saw a video on YouTube (I'll link it) where a mechanic was talking about how the fuse boxes on similar years of Chevy express vans have been known to go bad and cause low fuel pressure/crank no start issues so I'm wondering if this could be the case and how I would rest for that if so. Thank you for any advice! Here is the video: https://youtu.be/8Tr5Rk2Q1xg
Ella

Hi Joe!

Thanks for getting back to me, sorry it took me a while to respond. I found a pin for the fuel pump relay that has power at all times, but I was a little less than 12 V. 11.7 or something like that. However, my battery was not fully charged at the time because it keeps draining due to a short, so I need to redo that test with a healthy battery. I was wondering what was draining my battery all the time and I remembered that a couple weeks ago someone told me that my horn randomly went off for about 30 minutes while I was gone. My horn itself seems to be damaged now because it only sounds like half its former self. Sure enough, when I went to try and start my van today, I reconnected that battery (I've been leaving it disconnected to try and prevent a strain on it from the short) and I heard a weird gurgling noise coming from near my fuse box. I noticed that my horn relay was hot, so I pulled it out right away and the noise stopped. Whenever I put the relay back in the noise comes back. I don't really know exactly where it's coming from, and it just sounds like a strange gurgling. I also wanted to say that the actual holder of my fuel pump relay has experienced a lot of corrosion in the past and although I've tried to clean it up, I think it has pitting from the corrosion. I'm wondering if this is resulting in a bad connection with the fuel pump relay even though the relay itself is closing. I was wondering if you might be able to send me a wiring diagram that has my horn circuit on it? I was going to try and track down that short. Even though I don't think it's related to my no start issues it's definitely not helping.

Hello,

I just wanted to add that I charged my battery up more (although it was still at 12.4 ish when I checked unfortunately) and I checked that pin on the fuel pump relay holder again and this time it read around 12.37. However, my fuel pump is still not running. I can hear it trying to very weakly for a second, but it doesn't build up enough fuel pressure to start the engine and it is way quieter and weaker than usual. I did get the van to start yesterday but I'm not sure what it was that got it to work. I traced all the fuel pump wiring by hand and wiggled it around and also applied Dialectric grease to the relay. I can't seem to recreate that today.

Hi Joe,

That makes sense I will get a new horn relay asap and try it out. I haven't tested the voltage at the fuel pump yet, I can do that today or tomorrow. I know there are 4 wires coming from my fuel pump but I'm not exactly sure which one should have power at all times. Do you mind helping me out with that? Thank you and I really appreciate all your help.

Thank you so much for the wiring diagrams that's very helpful. I see the grey wire coming from my fuel pump connector. So that grey wire should have around battery voltage with my key in the on position, right?

Thank you. Then I will try to test for power at that grey wire while someone turn on the ignition. I think I can disconnect the fuel pump clip and put my multimeter leads directly on the ground and power pins. I'm a little stuck and wondering where to go from here now. I know my fuel pump doesn't seem to be getting power although my relay is working and my PCM is giving the signal. I just don't really know where to go from here. The issue could be within the fuse box itself, a grounding issue, or anywhere along the wiring going to the fuel pump. I want to recheck all my grounds soon because I have had other strange electrical symptoms like intermittent dash lights in the past and I wonder if there could be a bad ground somewhere. Any input on other tests I should try or stuff to check would be appreciated. Thank you as always and have a great evening!

Thank you, that's a very helpful response. I will let you know when I get the results of checking the power at the fuel pump. It's been raining a lot so hopefully I get a chance soon!
Best,
Ella