ETRBUJ1984

Just wondering if the 85 fuel pump swap is a good upgrade for the 84? And which brands to stick with, something like the Delco or holley? My fuel pumps not bad just wanted some input and thoughts on the subject.

84wannabezo6

I put one in mine the old pump would barely make 11 lbs pressure

Cruisinfanatic

You don't have to spend extra on a fancy name brand pump. It's just a pump. Any auto parts store has them

Frizlefrak

And it won't give any advantage whatsoever over a correctly working stock 84 pump. What it will do is provide higher flow should you decide to mod the engine and dial up fuel pressure to accomodate the mods. On a stock engine, either pump is fine.

I used a Carter 85 pump in my old 84. $65 at Pep Girls and made in USA. Worked just fine.

84wannabezo6

I think the spec for 84 says 9-13 psi I didn't test on a dyno but my car now runs @ 13 psi and it runs a lot better

Frizlefrak

It says that, but they won't run correctly without at least 12 psi. Getting fuel pressure correct is critical.

ETRBUJ1984

Whats the best way to check my fuel pressure myself?

Frizlefrak

Testing on an 84 is a PITA....so do this, and then it will be easy.

Buy a 0-15 psi vacuum / fuel pressue gauge. Remove your crossover tube. Take it to a hose and tubing shop and have them sweat in a fitting, and the corresponding fitting on your guage. Reattach and test. From then on, you can test easily just like the tpi guys.

Best mod I ever did on my old 84.

Tom400CFI

That works. And makes future checks easy. Here is a different, simple way to check. I used to simply "T" into the rubber hose between the frame rail and the engine. Loosen the hose clamp on the engine side, pull the hose off, install a "T" fitting and a short piece of hose on each of the two remaining barbs. Plug one hose back onto the hard line going to the injectors, and the other to your gauge. Run the car, watch the gauge. Easy. Cheap.



This is 100% correct.

FASTAZU

like ported intake.

j3studio

Clever!

ETRBUJ1984

After I can check my fuel pressure, if it's off how can I dial it in and get it back into the 13 psi range? Also does the front and rear have different pressure?

Tom400CFI

Remove the FPR, grind the weld blob off it, and turn the screw COUNTER clock-wise, to increase spring tension and fuel pressure.

Rear TB has the FPR and adjusts the pressure for both TB's.

corvettenorway

i run ported intake . 16 rr . carter pump .14 psi . 50 mm tb . ignition timing 10 .+++++++ !!!!!!! runs great !!!!! lots of fun !!!

Frizlefrak

Yes. They are two different sized injectors, and are not interchangeable. Because they are plumbed in series (not parallel), pressure falls off somewhat after the first injector. The rear one is larger to compensate for this. Hence, two different part numbers.