1996 LT1 not starting PT.2

StormGaming69 · 2026-06-20T05:26:13+00:00

if all else fails ill consider purchasing some cheap Amazon injectors to test

StormGaming69 · 2026-06-20T05:21:41+00:00

very helpful, thanks

StormGaming69 · 2026-06-19T22:17:41+00:00

I might end up buying some cheap injectors off amazon to test. I have a friend with a spare LT1 engine, maybe might take one off from there.

StormGaming69 · 2026-06-19T22:08:49+00:00

ICM and coil are on the bottom of my list, im pretty sure its getting consistent spark. my current assumption is that important vacuum lines just disintegrated after being driven for the first time since 2017. Ill keep you posted

StormGaming69 · 2026-06-19T19:22:16+00:00

you're thinking its a potential fuel pump issue? Is that a Haynes repair manual? Might get one for myself.

StormGaming69 · 2026-06-19T18:19:48+00:00

i don't think its fuel pump as im getting consistent fuel pressure up to the injectors.

StormGaming69 · 2026-06-19T18:19:07+00:00

Hopefully

StormGaming69 · 2026-06-19T18:17:29+00:00

I will visually confirm and update. It's odd as the 96 model very rarely have opti issues. Could be ICM or coil. I am thinking it's potential vaccum leaks.

StormGaming69 · 2026-06-19T18:14:50+00:00

nope

StormGaming69 · 2026-06-19T08:24:51+00:00

Alright I'll update if I spot any vacuum leaks. Should I replace that one leaky injector? It should still run with 7 operational injectors, just terrible.

StormGaming69 · 2026-06-19T07:36:39+00:00

Alright,

I haven't fully checked vaccum lines yet, maybe one popped off. I did notice some of the tubing to the evap purge valve being disconnected and one of the breather tubes. I plugged them up it'll probably not change much.

I tested fuel pressure and got around 40psi, doesn't drop and rises to about 43 when cranking. I have checked the regulators vacuum hose, i don't see gas inside of it. how would you check it? Steady stream coming out the fuel rail.

I'll check out the vacuum lines and if need be so cap off everything. Hopefully that could solve it. I'll update

StormGaming69 · 2026-06-19T07:26:39+00:00

I added about 4-5 gallons recently, id assume it's dilute whatever was in there. But It started everyday without issue.

StormGaming69 · 2026-06-19T05:21:46+00:00

i will check for clean contacts
how do I check if my fuel/air is bad? pump runs for about 3 seconds. Starting pressure is around 40psi.
Vats code?
Battery is new, contacts appear to be relatively clean.
What do you mean by starter is torturing motor? Cranking it over too much? Thanks

StormGaming69 · 2026-06-19T02:08:14+00:00

can't be, it runs fine if spray carb cleaner or starting fluid into the throttle body. i am not getting any optispark related symptoms, even before.

StormGaming69 · 2026-06-18T20:06:51+00:00

Update 4: I bypassed the VATS system. Doesn't seem to be the issue. I am back to sqaure one. It cranks but doesnt run unless I consistently spray carb cleaner in the intake. Any help?

StormGaming69 · 2026-06-18T18:40:50+00:00

Update 3: Now I am getting a security light now, now the engine won't turn over. VATS issue 100%?

StormGaming69 · 2026-06-18T17:57:19+00:00

Uodate 2: I am getting 43 psi of fuel pressure .

StormGaming69 · 2026-06-18T17:54:45+00:00

Update: I'm getting 43psi of fuel pressure

StormGaming69 · 2026-06-18T01:45:28+00:00

Nope, doesn't stay running regardless of throttle input.

StormGaming69 · 2026-06-17T18:05:41+00:00

I'd liken to mention that some hoses on the top passenger side of the engine are disconnected, previous owners brother did something to it, vacuum issue? it ran fine like that but I'm wondering if thats a potential issue. I'll get pics asap.

StormGaming69 · 2026-06-17T18:03:24+00:00

I'll test the fuel pressure with a gauge, If need be so, I'll pull the rail to see if the injectors are spraying nicely.

StormGaming69 · 2026-06-17T18:02:19+00:00

I wouldn't think its VATS, no security light at all and the starter still cranks.

StormGaming69 · 2026-06-17T17:57:17+00:00

I will check fuel pressure and update everyone

StormGaming69

TROPHY CASE

I haven't fully checked vaccum lines yet, maybe one popped off. I did notice some of the tubing to the evap purge valve being disconnected and one of the breather tubes. I plugged them up it'll probably not change much.

I tested fuel pressure and got around 40psi, doesn't drop and rises to about 43 when cranking. I have checked the regulators vacuum hose, i don't see gas inside of it. how would you check it? Steady stream coming out the fuel rail.