It keeps getting better

[331strokerlx]

Thanks for all the replies when I have time tomorrow I will test the volts. Since the motor isn't stock if it is the fuel pump would I be better off getting a bigger fuel pump. I didnt know if the motor being a stroker motor and bigger injectors would burn up a stock fuel pump.

 

[1993SSP]

What size pump do you currently have?? Most modded engines with bigger injectors do require a larger than stock pump.

 

[331strokerlx]

As far as I know it is a stock pump and I am running 30# injectors

 

[ryan218]

fuel pump relay. its under the drive seats. 20 dollar part. pull yours out and smell it. if it smeels burned. replace it.

 

[1993SSP]

I am running 30lb injectors, I have a 190 fuel pump on my car. Is your car tuned?

 

[331strokerlx]

the car hasn't ben tuned yet.

What does the relay look like?

 

[Chuckman]

if its under the seat, its a green box looking thing, under the hood its a black box. about 1-1.5" square with 4 wires going to it.

 

[1993SSP]

Have you got that car fixed yet?! With all this info you have surely done some tech work and narrowed it down or fixed it by now

 

[331strokerlx]

If it stops raining here I will get to it. But with the car being on the street in the rain it's a little difficult to fix. Im hoping for tomorrow. It would also help if I had the funds to buy new parts.

Found out from my stepdad that he is getting a new car next month and he is giving me his car to drive so we can turn this car into a strip car. His car is a beater car but it will get me around town

 

[67coupe]

I had a similar problem twice, 6 months apart. Fuel pump would not prime. 1st time, 7:00 in the morning, took the 67 to work. Car started on first try when i got home. Just in case, i bought a new relay and kept it in the armrest.

6 months later, it happened again. Installed the new relay, still no prime/start. I was able to turn the pump on by using a paper clip to jump KAPWR (Wire 1, black/orange) and FPM (Wire 19, pink/black). Once home from work, I was ready to finally troubleshoot this problem. Everything worked fine, with both relays.

I'm very interested in what happens with your car as I still haven't solved mine. The problem hasn't repeated since April.

It appears my problem was not the pump, pump wiring, or inertia switch since the pump cut on with power to wire 19. That leaves the only possible cause as no 12V on VPWR or wire 22 not grounding out. I'm leaning toward the ECU ground (wire 22) since the engine ran fine after jumping the relay (VPWR provides 12V for the injectors and MAF). I have a Multimeter and wiring diagram in the car for next time...lol.

Didn't see it posted, but this diagram should help you out.

http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Hope your problem gets solved.

 

[331strokerlx]

Ok I looked under the hood for the relay since the car is a 91 and all i saw was a tangle mess of wires and nothing that looked like it had 4 wires going into it

I never noticed it but when I turn the key to start the car after the normal amount of time the fuel pump would have primed I hear a click from the back of the car. Does that mean that it is getting power and the pump is shot.

Also when I was under the hood I fould by the firewal on the drivers side there is a big tube that says vac that isn't hooked up. What does that go to and is it a problem if it isn't hooked up.

I will post pics in a few hours when I get home. Thanks

 

[331strokerlx]

So I did some more looking around and under my intake pipe I found a box that is connected to the shock tower that has 4 wires going into it, is that the relay

 

[1993SSP]

Yes, that's most likely it. Sorry I didnt suggest it earlier but you may want to look into buying a repair manual if you're gonna mess with these cars, comes in very handy.

 

[331strokerlx]

I unscrewed it from the shock tower and is it supposed to pull apart. It looks like it is clipped together but I can't seem to unclip it.

I have the haynes repair manual but the diagrams are like chinese to me

 

[1993SSP]

they can be a little stubborn, I think you have to squeeze the plug for it to come apart best I remember

 

[331strokerlx]

Ok got the relay out and it looked fine and didn't smell burned up. So is it looking like the fuel pump now.

What size fuel pump should I get. I am going to 50 resto tomorrow?

 

[5.0Droptop]

get a 255lph pump.

 

[331strokerlx]

Is there a big difference between the 190 and 255. Does having a bigger fuel pump kill the gas mileage?

 

[5.0Droptop]

yes there is a difference. No the bigger pump will not change mpg at all. It just flows more fuel. Any unused fuel is bypassed directly to the tank.

 

[331strokerlx]

tomorrow I will go up to 50 resto and get the 255lph. It seems like a good deal it is only 119 dollars. Will I have to adjust the fuel pressure regulator after the pump is in?