Thanks for the input. I have definitely been searching the forums. I did replace my fuel pump (not oem, had already been replaced) with a new one at the advice of a mechanic. Everyone seems to say that it doesnt seem to be my injector assembly beacause my fuel pressure holds really well when i turn the key off and leave it for a couple minutes. However after replacing my pump im still getting the same slightly off fuel pressure readings as before replacing it. I get 60-62psi koeo and it cranks and starts up well. Then drops to around 55 psi idling. The concerning thing is that the prssure doesnt change at all when i snap the throttle. I checked my stftrm readings and they seemed to rule out a vacuum leak. The mechanic ive been talking to who is pretty familiar with these engines tells me the pressure should be jumping up to 62 psi when i snap the throttle but i havent been seeing that at all. Im so confused and dont reallt know where to go from here. Can anyone give me some input oj what to check next?
Its not this because i can always hear my fuel pump priming
Yeah I used to carry a five pound hammer to bang on the tank. Now Iāve been told you can ruin a pump by testing it dry. I have also had a bad connection at the pump. Cost me $100 to have the guy clean up the connection. Another issue is that there may be a fuel pressure shut off switch at the oil sensor. I think it is supposed to shut the fuel off on som gms if pressure is lost. There has been some difference of opinion though on how it is supposed to work. Also they say to change the pigtail and relay when changing pumps.
Hmmm. No spark though? Crank sensor? Oh heck, just replace everything.
Interesting ive never heard of the fuel shut off switch ill look into that. My connections look totally fine but ill replace the pigtail and connector anyways. At this point im just wondering why my fuel pressure isnt responding to me hitting the throttle. Theres clearly something wrong there. And i dont want to replace anything else unless i have a really good lead. I have limited funds. The reason i care so much about this van is because i live in it.
Not to lead you in the wrong direction. I think not all models had the fuel pump shut off on the oil pressure sensor. A schematic would show it or even a picture of the connector. Just something that came up in the past. The fuel pressure regulator though would produce the regulated fuel pressure regardless of throttle, unless it was producing too little pressure. The regulator canāt produce more than the pump can provide. I too wonder about it not popping off with the starter fluid. That would mean a spark issue but not hard to at least test for spark.
Thank you. Yeah it was strange that it had a hard time starting with the starting fluid last time i was broken down. The funny thing is since the last time i got towed ive had absolutely no issues getting it to start every time. So i havent even been able to reproduce the crank no start condition. Its just so intermittent.
Hi Iām back 
. I changed my fuel pump and the van seemed to be running pretty well for about a week now (although I have to prime the fuel pump once before starting it or it starts rough, fuel pressure reading looks fine). However it just did the crank no start thing again today. The only way I got it to start after trying lots of things (unplugging MAF, clearing codes etc) was to stand on the back bumper and just start bouncing it super hard for a minute. Then it sputtered to life and drove fine all the way home. Anyone have any ideas?? Iām at my wits end
lol ā¦ very original thinking there, but just curious, what caused you to try that method? Symptoms seem consistent with problem remaining in fuel pump or fuel pump electrical connection. Since the pump is new, probably the latter. Re-check all the electrical connections to the fuel pump . May need to ask a helper to wiggle the connections while you crank the engine to narrow down where the problem is. Depending on how thatās done, could be a safety concern if car starts unexpectedly with helper tweaking the connections, so be proactive in favor of safety.
Haha the reason I tried it was because the past few times Iāve gotten my van towed it immediately started working afterwards. I wondered if all the jostling was somehow fixing the issue temporarily. Not only did bouncing my van seem to fix the issue this time, itās now starting even stronger than before. Also I just replayed my fuel pump electrical connections (spliced in a new 4 pin connecter) when I replaced the pump. I think my next move is gonna be to look at my fuel filter again even though I changed it recently (before I changed the pump) because I got the best fuel pressure reading Iāve seen so far right after changing the filter. Maybe there was more crap in my gas tank thatās getting lodged in the new filter too. But it really didnāt look bad in there when I was poking around while changing my fuel pump. I was also thinking of looking into the rollover switch although this seems unlikely because I can hear the fuel pump priming when the crank no start issue occurs.
you can check out this video I came across and see if yours is doing the same. it might be the VATS system causing the problem.
I am just not sure if your year has one. it might have started in late 97 or 98 for your vehicle.
Thanks for the input! Itās funny Iāve actually watched that video before. I tried the key trick once and it actually worked but it hasnāt ever worked since then. So very confusing. I also have no idea what anti theft system is supposed to be in my van that information seems to be impossible to find. I believe it is supposed to be passlock. Anyways I still havenāt totally ruled out antitheft system issues. The other thing is my van turns over without a key just by twisting the lip of my ignition cylinder (I bought it like this) so it seems like that should not be happening if there was an antitheft system active. Iām very tempted to just replace the ignition cylinder since itās clearly wonky but Iām scared of waking up an antitheft system gremlin since that stuff needs to be reprogrammed when you replace it.
Well fuel pump again. Ive had them go two blocks from the shop. Walked across the street to call a tow, and car started again. Thee in a row
Bad out of the box
GM has had ignition switch problems for over a decade. there is a recall starting in 1997 to 2014. I would start with getting the switch replaced under the recall to see if this is the reason causing your problem. your switch is bad because youāre not supposed to be able to turn the switch without the key. so why not take that out of the equation.
Plugged fuel filter possible, but symptom for that is usually car runs ok until above a certain speed, then it bogs down. So fuel filter problem doubtful. Ignition switch problems seems more likely. Ask shop to check for proper input volts to ignition system and fuel pump when cranking. If thatās ok, ask them to check for visible spark at spark plugs during cranking. After that, check for proper pulsing of injectors during cranking. Still a cranks ok but wonāt catch and run? Fuel pressure check.
Iāve experienced a weird cranks ok but wonāt start problem before, caused by the cylinders flooded w/gas. But that was the result of prior fuel system testing. If you think that might be the problem, and the spark plug tips look wet, coated with fuel, remove all the plugs and let the fuel evaporate from the cylinders maybe.
OP notes above: " I have to prime the fuel pump once before starting it or it starts rough"
Something amiss. Could be related to cranks but wonāt start. Fuel from fuel rail could be leaking back into tank (faulty fuel pump check valve) or from fuel rail into cylinder(s) due to faulty injector(s). Fuel pressure hold test is how to check.
Thank you! Yeah Iām finally taking it to a shop on Monday so Iāll ask them to look at some of that. Iām a little nervous and hoping Iāll be taken seriously and that theyāll listen to how much Iāve learned about it already but Iāll just have to see how it goes. I checked my fuel filter again today (changed it recently too) and it seemed totally fine. I did suspect that too because Iāve stalled out about 3 times when taking my foot off the gas. Not sure at this point if thatās even related to the intermittent crank no start. I think looking at the ignition switch is definitely a good idea.
Thanks for letting me know about the ignition switch problems I hadnāt hear of that. Iāve been wanting to just go for it and change our my ignition switch and lock cylinder but Iāve been hesitant because I donāt want to wake up a passlock gremlin. I guess at this point it seems worth it though.
When the engine wonāt start, open the throttle and see if the engine starts.
That hasnāt worked for me past unfortunately I have tried it several times
Just an update on my van I took it to a mechanic and he checked it out for about an hour and a half. He ended up not charging me because he couldnāt recreate the crank no start (which I kind of expected since it often happens only one every 4 days or so) and he couldnāt find anything wrong with it. He did point out that the clamps around the tube that comes out of my air intake downstream of the MAF and throttle body were way too loose and he tightened those. I noticed that my van idles a lot quieter after that. But I doubt that could have been the problem since during the crank no start issues it would start with starter fluid which seems to indicate a fuel delivery issue, right? Iām bummed he didnāt find anything but he was super nice and I hope that tightening those clamps helped. Iām just gonna keep driving it as much as possible for the next week and only stopping in safe places and see if I can get it to happen again.
So Iām still experiencing the issue. It now manifests approximately every 4 days or so and I first noticed that it starts rough (cranking for longer than usual maybe a little sputtering) but will then run fine. But then the next time I go to start it it will crank and start for 1 second then die immediately. And after that it will just crank and crank. Iāll then go and jump up and down on my bumper a bunch and it will usually start. Iāve also tried removing my fuel pump relay and putting it back in to sort of start the priming process over (btw I always prime my fuel pump koeo a couple times before cranking) and this has worked once as well. Iām so baffled by this. Iām wondering if it could be the purge valve/ solenoid because this issue first manifested as hard starting after I filled up with gas. Iām going to try to check out my purge valve and solenoid today. However itās really hard to confirm these things when the issue is not present. My van is currently starting fine since the last incident of no start occured 2 nights ago and I couldnāt check it out then because just needed to move my van quickly. Does anyone have input on the purge valve/ solenoid lead? Or other ideas?