1998 K1500 GMC 4.3L won't start after changing intake manifold gas

[Ike42]

I replaced my intake manifold gasket on my 1998 GMC truck K1500, 4.3L Vortec, 188,000 miles. After I got it all back together it will not start at all. It cranks well but fires only a little, like maybe on on cylinder. There is spark at each spark plug and the distributor timing is correct. I verified that the spider is connected to the proper cylinders in the intake. I do not smell any fuel at the exhaust.

 

It WILL run a few seconds on starting fluid.

 

The truck started and ran fine before I did this work on it.

 

The battery was disconnected for a couple days.

 

I don't have a fuel pressure gauge or a noid light yet, so I have not checked those.

 

Does any one have any ideas for common things that I may have done to cause this?

 

Thanks

 

 

[Jsdirt]

Go over everything and make sure you didn't miss a connector or vacuum line - very easy to do, as there's a billion of them all over these engines.

 

If it seems to start for a second and then die, with the "security" light flashing, check for a blown fuse in the under-hood fuse block.

[Ike42]

JS,

I looked it over again and I don't see any connectors that were left off. No security light flashing, engine won't start at all now.

 

I got a loaner noid light and checked that each circuit is making the light flash. They are all working.

 

Then I got a fuel pressure tester. It reads 59- 60 PSI Key on, engine off. It loses about 5 psi in 5 minutes after turning off the key,

 

I have pulled the upper intake off again and am thinking of trying to clean the poppet valves portion pf the injectors.

 

The MFI conversion sounds good but can't afford it right now.

[Minnesotawinter]

Hello Ike42, what was your resolution to the non-start issue? I'm currently in the same place you were at, and am perplexed on how to get my vehicle started again.

 

Thanks for any insight.

[Minnesotawinter]

Okay, a follow-up to what I did to get my 4.3L Vortec running again:

 

I removed the fuel injector spider and searched on how to clean it. The majority of the forums stated to not bother and to upgrade from the Central Sequential Fuel Injection (CSFI) to Multi-Port Fuel Injection (MPFI) system.

 

So I order a new MPFI spider from RockAuto for just under $180, installed it, and the engine started up on the first turn of the key. The local parts store wanted $316 for their version of the same part, by the way.

 

Several days later I have to admit that I never realized how hesitant the engine was when I hit the gas. This new fuel injection system was well worth the money, the engine is very responsive and there is not a hint of hesitation when I stomp on the gas.

[Duelin]

Okay, a follow-up to what I did to get my 4.3L Vortec running again:

 

I removed the fuel injector spider and searched on how to clean it. The majority of the forums stated to not bother and to upgrade from the Central Sequential Fuel Injection (CSFI) to Multi-Port Fuel Injection (MPFI) system.

 

So I order a new MPFI spider from RockAuto for just under $180, installed it, and the engine started up on the first turn of the key. The local parts store wanted $316 for their version of the same part, by the way.

 

Several days later I have to admit that I never realized how hesitant the engine was when I hit the gas. This new fuel injection system was well worth the money, the engine is very responsive and there is not a hint of hesitation when I stomp on the gas.

 

 

Thanks for the follow up . Glad that took care of it.