by "Jake - Has Bad Luck So You Don't Have To" (murdersofa)
Published 04/25/2017 at 11:46
by "Jake - Has Bad Luck So You Don't Have To" (murdersofa)
Published 04/25/2017 at 11:46
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STARS: 0
My sister’s truck, a ‘99 Silverado 4.3 V6 is having occasional non-start issues. I’ve never gotten it to happen to me but it’ll crank but not fire, then a few minutes later my dad will come out and try and it’ll be just fine. No codes or anything that I can pull. The ignition relay felt a bit warm so I swapped it with the starter relay (both are identical Hella relays) so now if it doesn’t start but also doesn’t crank I know it’s that relay, but my other thoughts are something wrong with the signal to the coil pack (conveniently mounted on the back of the engine where I can’t get it) or the weird spider fuel injection monstrosity (also where I can’t get to it easily). Anyone here have this issue before or have familiarity with these engines enough to knowif it’s something easy/common?
"gmctavish needs more space" (gmctavish)
04/25/2017 at 11:50, STARS: 0
The spider injector is known to be a problem, but if that relay is bad, I’d change it out before digging into the injector assembly, or trying to get at the coil.
"Smallbear wants a modern Syclone, local Maple Leafs spammer" (smallbear94)
04/25/2017 at 11:52, STARS: 0
The 4.3 still had the spider injection in ‘99? Seriously?
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 11:54, STARS: 1
Yeah, I’ll know for sure if it’s the relay if the car fails to start again depending on if it cranks or not.
"Textured Soy Protein" (texturedsoyprotein)
04/25/2017 at 11:55, STARS: 0
I had long crank issues with my car when its high pressure fuel pump was going out. This is a common failure point on direct injected BMWs like mine. Replaced the pump and no more problems. Totally different setup from this truck of course but maybe it’s a fuel issue?
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 11:56, STARS: 3
“Hey TBI is lame let’s do something worse” -GM, probably
"ITA97, now with more Jag @ opposite-lock.com" (ita97)
04/25/2017 at 11:56, STARS: 1
The 5.7 did too.
"crowmolly" (crowmolly)
04/25/2017 at 11:57, STARS: 1
Check the fuel pressure regulator.
Edit: Just so you don’t think I’m throwing darts, I had the same issue with a 2000 silvy.
"Die-Trying" (die-trying)
04/25/2017 at 11:58, STARS: 4
could be the fuel pump check valve. it might not have fuel pressure when you go to crank on it, but after the key has been cycled a few times you then have enough pressure for it to start and run just fine........
"Smallbear wants a modern Syclone, local Maple Leafs spammer" (smallbear94)
04/25/2017 at 11:58, STARS: 0
Is there any way to retrofit something else? If it turns out to be the problem I’d try that before I’d put in a new spider setup
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 12:00, STARS: 1
2001+ intake manifold has MPFI but the electrical nightmare of getting it to work is not worth it.
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 12:00, STARS: 0
That was my initial thought but she’s claimed to try several times a few minutes apart and it still wouldn’t start.
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 12:01, STARS: 0
My first thought was fuel but the symptoms don’t quite line up. Fuel pump was done fairly recently, too.
"traitor joe" (traitorjoe)
04/25/2017 at 12:02, STARS: 1
I had this issue with a 4.3 TBI. Eventually, it would just crank without starting at all. Turned out to be part of the distributor - there is a magnetic stator that has to spin at a certain RPM before the ECM will give fuel and spark. The stator had gotten so rusty it would no longer send a proper signal, so the ECM thought the engine wasn’t turning and wouldn’t allow it to start. The fault was easily seen by disassembling the distributor. Without seeing this, I would have concluded that the ignition control module was faulty instead - which is most likely your problem. If you have access to it, try a complete new distributor assembly to narrow down the problem.
"Die-Trying" (die-trying)
04/25/2017 at 12:12, STARS: 0
right, and after about a minute the pressure has had enough time to bleed back off.
there should be a spot to check the fuel pressure under the hood. its been a while since i looked at one of those. but hook up a gauge, and see what the pressure reads. then see what it builds to with one cycle of the key to start it, and see if it bleeds off.... i cant remember exactly what those need to run, but it should be in the area of 30 psi(if i recall(you should look up the exact number))...... when you cycle the key a few times fairly quick, it should build to about there, and start without issue.......
some scan tools show fuel pressure too.....
its also getting to the ripe age where electric parts start to go, like the pickup in the distributor........
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 12:13, STARS: 0
Alright. Did it smell like gas when you were starting it? Seems like that would be a good indicator of fuel but no spark but, as I’ve never witnessed it not starting I have no idea.
"traitor joe" (traitorjoe)
04/25/2017 at 12:16, STARS: 0
After a quick google search, I believe your model has a separate “camshaft position sensor” in the distributor with an external ICM. From my experience one of these is almost certainly the problem.
"Dave the car guy , still here" (a3dave)
04/25/2017 at 12:21, STARS: 1
It was junk. GM had a kit in bulletins for fixing those spider injected ones for years. GM has now discontinued the CPI poppet type injector parts for GM dealers. There is a kit to retrofit to the poppet system to MFI type injection. The poppet tubes on the conversion have electric injectors installed inline on the spider. The first kits years ago were just by Delco , but now Delphi, Airtex/Wells and Standard Motor Products now all make a kit. It get rid of the poppet issues and improves drivability and fuel mileage gets better on most swapped vehicles.
"Dave the car guy , still here" (a3dave)
04/25/2017 at 12:24, STARS: 1
If he does need the spider setup he needs to switch from the poppet kit to MFI conversion I just mentioned in another reply. Its the way to go on fixing those.
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 12:26, STARS: 1
Yeah I’m thinking it’s the dizzy pickup or the coil. It isn’t consistent enough to be a fuel pressure issue (especially considering the less-than-3-year-old fuel pump)
"deekster_caddy" (deekster_caddy)
04/25/2017 at 12:27, STARS: 0
I don’t think a ‘99 still uses a distributor? It does have an ICM though and those do go bad when hot.
"Danger" (dangerray)
04/25/2017 at 12:28, STARS: 0
My best friend’s 4.3 did this more and more often until we started poking around and realized it would start after smacking the fuel pump with a hammer. Fuel pump was bad, and expensive back then. Once the new pump was in, it stopped happening. Next time it won’t start, smack the fuel pump and see if it goes.
"deekster_caddy" (deekster_caddy)
04/25/2017 at 12:29, STARS: 2
Any chance the security light is flashing? Are you or he using the OE key or a remade key? If it has VATS the ignition key has a resistance to it that can be measured by the security portion of the ECM - if no match, no start. I think it disables the fuel pump or ignition but may still crank. Make sure the key is clean and dry and make a note of which key is in use when it won’t start.
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 12:33, STARS: 0
Oooh, that would explain why it starts for my dad every time and only some times for my sister. I’ll mention that.
"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
04/25/2017 at 12:35, STARS: 0
Pump is less than three years old on this :/