BigDave

Hey guys Im new here, so hello. I just finished replacing the fuel pump in my 1994 sport. Now I'm having trouble getting it to start. I can hear the pump coming on intermittenly, probably four out of five times that I turn the ignition to the on position it will engage but there are times when it wont. Any suggestions?

okcjeeper

Moved this post here so you will get more responses and input.

My only thing would be are you getting fuel pressure at the fuel rail? Also have you check the sending unit/plug with a voltmeter?

Oh and welcome to the site.

BigDave

Thanks.

From just turning the ignition to "on" I dont get a pressure reading, and cant get it to start in order to take one from Idle.

Do I need to pull the pump back out to test the voltage?

BigDave

Checked the relay, it's good. Filter is new. My Ignition system is new.

Before swapping pumps my fuel pressure was sitting at 15 PSI and I was pumping way lower than a pint every thirty seconds. It would idle smoothly after about five minutes of starting and dying with a big spike in RPMs. All indicative of a bad pump.

Since putting in the new unit, the engine turns over but doesn't fire. Im getting fuel out the schrader valve in the ON position. My pump comes on for a couple of on/off cycles than wont come on again until I try to start it.

I took the new pump out and stuck it a bucket of gas, hooked it up direct to power, and its pumping. Any help or Ideas?

BuckB91XJ

Sounds like you got the same screw job I got when I replaced my fuel pump. It was bad right out of the box.
Here is a really inexpensive way I figured out to verify a good FP.
Take just the pump itself without any of the mounting bracketry. Acquire yourself a small container to put about a pint of fuel in. Make yourself a set of electrical leads about a foot long that you can hook to your fuel pump and then briefly touch to your battery terminals. + to + and - to - is very important here. Trust me when I say this as it is the voice of experience. Once you hook up that positive lead and then just briefly touch the negative lead, with the inlet of your FP submerged in the container of fuel, gas will SHOOT and I mean shoot out the outlet of the FP, clear across your garage. If this does not happen just like I stated, the FP is bad....Take it back and get another or your money back.
The first FP I had, I tried this test and the FP made all kinds of noise like it was turning on but, no fuel was sucking or blowing. BAD Fuel Pump. The description above is what my second new fuel pump did when I tested it.

Metmknice

^^ He already said he stuck it in an some fuel and tried it.

vistacruiser

I'm no electrical guru but I have replaced probably 6 ,of these kinds of pumps in the last 10 yrs on different vehicles. Every one ran on the bench off of a battery ..... earlier this year my roomate, who is very hard headed and a know it all EE, put a non working pump back in after I had diag'ed it bad. He was indignant with me cuz it ran on the bench .... I just shook my head and thought ... let him learn the hard way. Of course he had to take it back out and re install a new one ... a big pain.

COSXJFAN

It may pump fuel at no load, but needs to generate enough pressure to flow through the system. Pumping in a bucket of fuel is in no way a viable test. It has to pump through the system...and be able to produce enough pressure to spray through the injectors. My guess is that it is a faulty pump OOTB. Take it back and get a good replacement. IMHO, you should buy the best FP you can, this IS one part that can leave you in the middle of BFE, wondering WTF you're gonna do!! Ask me how I know this. HTH!!

BigDave

I found out what went wrong thanks to buck, haha. The posts on the new pump were unlabeled so I hooked it up exactly the way the original was wired. When I took it off the harness and did the test it made noise but no gas. I thot **** it and switched the positive and neg wires and hey presto I had gas. It was a risk but it paid off. I just got in from my test drive and it's running like a dream. Thanks guys, for your input.

KPCork

this IS one part that can leave you in the middle of BFE

I have been to this place in Egypt. It is not a pleasant place to be without a fuel pump.

COSXJFAN

On the top of Tin Cup Pass wondering WTF am I gonna do???? No fun!!