1988 chevy stepvan 5.7L tbi

[brutis]

auto zone sells a fuel pressure tester have to ask for it , comes with a adaptor that you install in line after filter

[hotrodpc]

Are you sure you are getting a good spray out of the injector(s) at the TBI? Maybe just a clogged or gummed up injector from sitting. How did it run before it was parked? Or is this the reason it was parked? 4 gallons a minute seems like very good volume, so you'd THINK the pressure would be good. But, volume is NOT pressure, and you will need the 9-13lbs of pressure just to get the injector to open. I'd be leaning toward the fuel problem or as leo suggested vacuum. EGR also a great suggestion but sounds like you have that handled and its OK. I think you are on the right track though. Stick with working on the fuel system.

[hotrodpc]

BTW, Brutis mentioned AZone SELLS a fuel pressure tester. Many times, you can leave a deposit for the cost of the tool and they will loan it to you, that way you don't have to shell out the bucks for an expensive tool to use maybe once or twice. Also, its a cheapie, but Harbor Freight sells one too. Probably worth what you're gonna pay for it, but if you don't use it often, it may serve its purpose well for the lower price.

[Crmzendrgone]

HF really sales a fuel tester? Is that for GM or is it generic?

[jbarker]

My 94 K2500 350 had similar behaviour. Lots of other probs but one was the EGR - not the valve itself but the ports in the intake manifold were plugged solid. Had to bang it out. Other threads on this forum show the same prob with similar engine & age.
You might want to take a look.

[Crmzendrgone]

A guy that worked for GM I knew said "to check if the ports on the EGR are clogged/plugged push on the diaphram in the valve and if the idle changes and it will be noticable then the ports are clear." That is what I have been told.

[hotrodpc]

Originally Posted by Crmzendrgone

A guy that worked for GM I knew said "to check if the ports on the EGR are clogged/plugged push on the diaphram in the valve and if the idle changes and it will be noticable then the ports are clear." That is what I have been told.

I know exactly what you are reffering to Cz, but maybe a better expanation would be, reach under or behind the top top of the EGR and push the diaphram up or in to raise the pintel. If its up already, then your diaphram/pintle is bad and it needs replaced, or many times, taking it off a good cleaning and lube will fix it too, provided there is no holes in the diaphram. What is meant my noticeable idle change is, when you do push the diaphram up, IF working properly, you are going to create a major vacuum leak and you will certainly hear the hear engine stumble and run extremely rough and maybe even shut off its so rough. This is why when an EGR does fail in most cases, the vehicle idles terrible or does not idle at all. If your EGR is vacuum and not electric, you can also disconnect the vac line and hook up a hand Vac pump, and you should also get the very rough idle until you release the vacuum.

[gmctrucks]

Try some Seafoam by sucking some of it down the vacuum booster line maybe it will clean up the intake/injectors I have added some down the vacuum booster till it shuts down then I let it sit 30 minutes before starting up.

YouTube - Seafoaming The guy didn't let it sit for a while that's why it didn't smoke that much atthe beginning.

[Crmzendrgone]

Originally Posted by gmctrucks

Try some Seafoam by sucking some of it down the vacuum booster line maybe it will clean up the intake/injectors I have added some down the vacuum booster till it shuts down then I let it sit 30 minutes before starting up.

YouTube - Seafoaming The guy didn't let it sit for a while that's why it didn't smoke that much atthe beginning.

I like the idea of seafoam and all but I am confused how pouring it into the brake booster line will clean the injectors on a TBI. I also don't think pouring a 1/3 of it into the tank will clean the injectors well enough. I think the only way to do that is to use a machine or someway have the injectors pull the seafoam directly. I know shops have machines that act as the fuel tank and you cycle the cleaner what ever it is through that way. Just my thoughts

[Crmzendrgone]

Originally Posted by hotrodpc

I know exactly what you are reffering to Cz, but maybe a better expanation would be, reach under or behind the top top of the EGR and push the diaphram up or in to raise the pintel. If its up already, then your diaphram/pintle is bad and it needs replaced, or many times, taking it off a good cleaning and lube will fix it too, provided there is no holes in the diaphram. What is meant my noticeable idle change is, when you do push the diaphram up, IF working properly, you are going to create a major vacuum leak and you will certainly hear the hear engine stumble and run extremely rough and maybe even shut off its so rough. This is why when an EGR does fail in most cases, the vehicle idles terrible or does not idle at all. If your EGR is vacuum and not electric, you can also disconnect the vac line and hook up a hand Vac pump, and you should also get the very rough idle until you release the vacuum.

Thanks for clearing that up for me, I have a bad habbit of not being clear in my descriptions.