Bad fuel pump?

[JJT211]

So I bought a 90 TT that was having probs. The car is very hard to start and running like crap. It will barely stay running.

I connected fuel pressure tester before and after fuel filter and I'm only getting 10 psi.

I resistance checked the fuel pump and it's fluctuating from 2 to 100 ohms.

I know it sounds obvious it's the fuel pump but the fact that it's technically still pumping (I mean it's getting some pressure) could it be the fuel pressure regulator or dampner?

[amc49]

On most EFI systems the pump is usually the problem. At 10 psi the regulator isn't even doing anything, they don't LOWER psi per se, they LIMIT it. At 10 it is simply waiting for the number to come up to begin to limit it. Dampers rarely cause trouble too. It's almost always the pump and if the original then you are not wasting money at all even if it turns out to be other.

If they run ethanol in your local fuel look hard at that too, it reinforces what I just posted by like 5X. The ethanol eats the pumps in various ways.

If you have phase separated fuel in tank from sitting you are only making things worse.

[JJT211]

Cool thx for the quick reply.

I bypassed the PRVR (I'll prob just leave it bypassed), and the Fuel Pump Comp. Still not getting anything higher than 20psi. That's gotta be it. I'll report back

[itsa300zx]

If you are measuring at the fuel filter, the dampener and regulator has nothing to do with the low pressure, as they are down stream; unless you have a major leak in the injectors. Have a look at the fuel pump controller too, check that you have 12volt to the pump and not lower.