stumble on acceleration

[PirateVR6]

my uncle has/had a 1992 chevy astro w a 4.3L V6 TBI gas. it started overheating while he was coming home from Arkensas to Texas. he said

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[EricTheCarGuy]

If you don’t have any check engine lights I might be looking at the fuel pressure. First I would check the running pressure to make sure it was in spec but then I would check the fuel pressure regulator by removing the vacuum line while the fuel pressure gauge was still hooked up and the engine running, you should see the fuel pressure rise when you do this if you don’t then you have a faulty fuel pressure regulator.

Aside from that you might also want to check the timing to make sure that’s correct. I don’t know if it effects those years but on some GM models you need to set the timing via scan tool but I think yours is old enough where that’s not an issue.

Good luck and keep us posted.

[dreamer2355]

+1 on Eric’s post.

You can rent fuel pressure test guages from most autoparts stores if you do not have one.

[mossyoak83]

I have a ’99 s10 4.3 v6 tbi and for almost a year my s10 at random moments would stumble around, sometimes i could catch it while i wasnt moving, have to pedal to the floor and it felt like it was running at like 2,500-3,000rpm (my model doesn’t have a tach but i know what it sounds like when it wouldn’t act up). It would also do this on the road and would lose lots of power. I had my idiot light come on several times but that was only because it was missing which was from this whole ordeal. Anyways one night i parked on a slight angle to drop my gf off at her house and when i went out to start it…… nothing, I found out my fuel pump was not working (while it would run it would make a very loud zzzzzzz noise, much louder than my buddy’s s10). Checked the relays hoping i didn’t have to buy a $270 after market fuel pump or pay the $430 for an ac delco one. I ended up getting one from my buddy’s s10 he wrecked for $35 so i was happy, I stuck it in and It has since to act up (which has been about 14 months and almost 20,000mi) and is much quieter. I never diagnosed it previously because I didn’t want to have to put money into the truck , and it still ran and moved, just not like a healthy engine would.

I would recommend you checking fuel pressure. My story may or may not help but I just figured I would share my personal expierence with the same type motor and somewhat same symptoms. Good luck with your van.

[PirateVR6]

finally got some time to play with the van, turns out it has some bad piston rings. idk if it’s worth fixing to be honest.

[EricTheCarGuy]

If that’s the case and you do decide to fix it I would recommend a replacement engine, I’ve found that to be much less expensive and a lot less trouble than trying to rebuild one. Good luck and keep us posted.

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