JoeBobJr

I have an 85 Silverado that came stock with a carburetor. The guy before me pulled the carbbed engine out and installed a TBI 305 with 700R4 into the truck. I guess to save time he installed an inline pump which never seemed to do very well with the truck. It always seemed a little sluggish as if it wasn't getting enough fuel. I know the pump installed autozone claims it's for TBI engines but it rates from 7-12 psi. That's just fine if it held 12psi at WOT but of course it's not ever going to do so. I wanted to install a high grade higher psi inline pump and I did put one out of an 89 Ford pickup. They said it put out 70 psi+ which seemed to be too much but I ordered one anyways. I installed it and now the truck floods out like crazy. I've asked a few people online and they claim the TBI has a regulator that will get the fuel pressure down to whatever is needed that it's no harm to have way more psi then what is needed.

I first thought it was just a bad regulator on the TBI or something so I replaced the TBI about four times with different ones thinking I kept getting bad ones. Nothing I have tried has fixed it which brings me back to think it has to be the fuel pump. It seems to me that the fuel pressure it just too extreme for a TBI and it's pushing past the regulator which is causing the flooding. It sprays so much fuel it won't even idle. When it does it idles so bad it's horrible. Smoking like crazy also.

What do you guys think? I thought I might consider getting rid of the inline pump altogether and getting a sending unit from an 87 and putting a pump in the tank. I know I can install an 94 Corvette pump in the tank and it will give me way more then enough psi for the TBI to get all the fuel it needs even at WOT. I just don't know if my tank will hold a sending unit from an 87 or if I have to change out the tank also.

I did install a cheapo $20 fuel pressure regulator on the truck I got from ebay a few days ago. It said it could be adjusted from 20-140psi and I think they are full of **** or I got a bad one. No matter how I try to fine tune it, it either stays around 10psi or it goes wide open to 70 psi. I can't adjust it any where between. I'm just tired of spending money on trying to fix something and nothing seems to be working. Everything points to the pump but I hate to replace a brand new pump if someone believes it's something else causing the issues.

loosebearing

Factory fuel regulators can not be adjusted. Can get a kit so you can regulate.
But the fuel pump you have should work if return line is big enough.

OLD WRENCH

You need to get back to a pump designed for a TBI application. I THINK you can install a TBI pump in your tank and get rid of all this crap you put on that dont work.

JoeBobJr

I actually did a lot of research online to find a pump that would work with TBI that was inline. There were quite a few people who did conversations and used that exact pump for the installation. That's the reason I used it.

It turns out that my fuel return line was clogged completely at the 90 on top of the fuel element in the tank. I pulled all lines loose and blew air to find it clogged up in that spot. The extra fuel wasn't able to push back to the tank which in turn made it run extremely rich to the point it wouldn't run at all really.

I have fixed it and it runs at the moment. I have other issues not pertaining to fuel that I have to work out now. Thanks for your answers.

loosebearing

yep.....