90 K5 TBI starting troubles NEED HELP

[A1990RustBucket]

I've looked everywhere to a solution for this and have not even found someone with the same issue. I was using my K5 to pull logs the other day and when done, parked it in the backyard. Went out to move it about an hour later and has hard starting. It will crank over, fire a few times and die. I can keep it running by toying with the throttle but that's it. BUT... it will run on it's own once in gear, it just idles really low. Stumped most of the local mechanics.

 

[bigS10blazer]

fuel pump pressure ?

 

[A1990RustBucket]

Not sure. i dont have a way of measuring right now unfortunately... I'll try to finda gauge tomorow. It is a brand new fuel pump, but I know that isn't the only thing that can't go wrong.

 

[wheels87k5]

TPS come loose? or move out of position? Read somewhere on here where that was an issue. But I can't find it.

 

[A1990RustBucket]

Nope. All sensors and vacuum lines are ok. Now it idles high before stalling out.

 

[4X4HIGH]

Nope. All sensors and vacuum lines are ok. Now it idles high before stalling out.

You have a vacuum leak somewhere and lots of people have found the TBI base gasket to be the issue. Start with some carb cleaner and start spraying anywhere there is a vacuum source and you'll quickly find the problem.

 

[British Slave]

After checking vacuum leaks, check the EGR valve.

 

[A1990RustBucket]

Alright. I'll start on that tomorow. Fuel pressure was at 10PSI. but if i replace the gasket, what would be the best spacer to put in while I have it off?

 

[4X4HIGH]

Alright. I'll start on that tomorow. Fuel pressure was at 10PSI. but if i replace the gasket, what would be the best spacer to put in while I have it off?

Fuel pressure is a little low, GM says between 9-13 but all that i've checked were right a hair more than 12psi

 

[A1990RustBucket]

Would that little bit cause the issue? I had planned on upping the pressure eventually with some new injectors.

 

[454Sub]

Injectors wont raise the pressure, you either have to modify the factory regulator, which is easy, or buy an aftermarket one, a quick google search will give you a pretty good how to on modifying the factory one.

 

[A1990RustBucket]

Yea, i was going to modify the one on there with the kit from RVMorsem=Machine. i Might do the whole kit eventually.

 

[Kstanbach]

I've looked everywhere to a solution for this and have not even found someone with the same issue. I was using my K5 to pull logs the other day and when done, parked it in the backyard. Went out to move it about an hour later and has hard starting. It will crank over, fire a few times and die. I can keep it running by toying with the throttle but that's it. BUT... it will run on it's own once in gear, it just idles really low. Stumped most of the local mechanics.

Clean out the IAC if it has one; it's been a while since I've worked on a TBI.