Well, I just replaced my 305 TBI with a 350 TPI and I finally got it to fire, well to my suprise I have 20 psi MAX. how could this be? I have replaced the fuel pump(walbro intank), fuel filter, some of the fuel lines, injectors (SVO 24#), and added a Holley AFPR. I have the regulator bottomed and thats not helping at all. Please start giving me ideas on why I am only getting 20 psi? thanks

Jim

 

The first thing that pops to mind is the fuel filters are directional. Second is could you have a fuel line crossed somewhere. One thing you could do is put the old filter in if you still have it to see if the new filter is clogged.

 

the old filter is for a TBI setup so it's a low pressure filter. I got a new high pressure one for the TPI so they aren't interchangable. I'll recheck the fuel lines but I'm pretty sure they're right. thanks.

 

My car is an 88 camaro and the fuel filter is a cheap fram. It had arrows on the side for the flow direction. Did you put a tpi fuel pump in?

 

CG,

What happens to the fuel pressure if you briefly pinch the fuel return line from the regulator? If you close the line and the fuel pressure increases, the regulator is bypassing at 20 PSI (NFG). If the pressure remains the same, your problem is ahead of the regulator or you have severe leaks in some injectors.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Did you adjust the AFPR right? Just a thought.

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1990 Pontiac Formula 350
Rebuilt 355
COMPCAMS 212/212 .440/.440 cam
Flowmasters 80 series.

 

You can't adjust an afpr wrong, pulling the screw completely out will just yield stock pressure. Collapsed/clogged fuel line?

 

If Vaders check proves true (ie no change in pressure). It's going to be a PITA, but seriously consider checking the rubber line between the pump and hardline in the tank. From day one I had low fuel pressure (about 44PSI max) due to a leak. It lasted two years before blowing out totally.

 

alright I'll give all the ideas a try today and post the results. thanks again.

 

Well I just pinched the line and the pressure jumped to 60 psi!! So I guess that means it's the AFPR. any ideas? could I have installed it wrong or could it just be bad? Anyway I guess I'm going to rip it out again and try to figure out what I did wrong. thanks again guys.

Jim

Update:

Alright, I pulled the AFPR and the vacum side of the diaphram (sp?) was torn again . This is the second one I have torn. why is this happening? I tore the stock one and now the Holley. I'm sending it back to summit, but I don't want this to happen again. The stock one was barely hanging on by a thread. What's going on?

[This message has been edited by camaroguy99 (edited August 10, 2001).]

 

ttt