95 R Fuel System Issues

[StillIntense]

Need some advice here. Recently, I replaced the original fuel cell in my 95 R with a brand new one from Fuel Safe. Transferred over the fuel pump, fuel level sender, all lines and electrical connections without a problem. Put the new cell in the car. Now I have to crank the car for a good bit before it will start and once started, it runs rough and stumbles quite a bit until it warms up. Once warm, the car runs fine.
Of note, the fuel pump was in the old cell for about 3 weeks while it was out of the car, awaiting the new cell. Check the sock on the pump, no debris or anything else to clog it. No other changes whatsoever were made to the car except the fuel cell change.

Any advice/ideas about this issue? Is the pump now shot? What is the direct replacement part for this pump? It is the original fuel pump from the car, which has 20k miles and is tracked 4-5 times per year.
Mark:??:

 

[Robert M]

Need some advice here. Recently, I replaced the original fuel cell in my 95 R with a brand new one from Fuel Safe. Transferred over the fuel pump, fuel level sender, all lines and electrical connections without a problem. Put the new cell in the car. Now I have to crank the car for a good bit before it will start and once started, it runs rough and stumbles quite a bit until it warms up. Once warm, the car runs fine.
Of note, the fuel pump was in the old cell for about 3 weeks while it was out of the car, awaiting the new cell. Check the sock on the pump, no debris or anything else to clog it. No other changes whatsoever were made to the car except the fuel cell change.

Any advice/ideas about this issue? Is the pump now shot? What is the direct replacement part for this pump? It is the original fuel pump from the car, which has 20k miles and is tracked 4-5 times per year.
Mark:??:

I had my fuel pump in a sealed plastic bag for 3-4 months between the time I removed my cell for the bladder replacement and the re-install. I had no problems, the car starts and runs as it did before the "dreaded drip".

R

 

[StillIntense]

Hmmmm. I'm going to lower the tank tomorrow to see if perhaps the fuel intake line is loose where it connects to the top of top of the cell. Doubt it though, the clip went back on OK.

Any other ideas or even SWAGs Robert?

 

[svtguy]

You need to hook up a fuel pressure gauge to verify if it is a fuel stavation problem or not.


Paul.

 

[Robert M]

Hmmmm. I'm going to lower the tank tomorrow to see if perhaps the fuel intake line is loose where it connects to the top of top of the cell. Doubt it though, the clip went back on OK.

Any other ideas or even SWAGs Robert?

The "running poorly when cold vs. running fine when warmed up" has me confused. At first I was thinking the fuel feed was laying in a bad place on top of the tank and had become pinched or crimped as the tank was secured to the bottom of the car, but that should not be affected by warm vs. cold. If the fuel line were not properly installed, the high pressure fuel would be leaking and you would know it quickly.

R

 

[StillIntense]

Paul, the fuel pressure gauge will go on today for checks. Robert, after I see what happens with the fuel pressure gauge, I may lower the tank and see what is going on with the lines. I agree too, if the line were not properly installed, there should be pressurized fuel. Hopefully, I'll have an answer today. I'll let you know.

 

[StillIntense]

OK, installed the fuel pressure gauge and here's what happened:
Prior to turning the ignition on, pressure read zero. Turned ignition on; gauge began a VERY slow climb to about 4 PSIG, started car, stumbled and ran rough as before. Car would take fuel and rev OK. Gauge took about 1 to 1.5 minutes to climb to 37 PSIG. Revving the car a bit sped up the process. So, that explains why it runs better when warm: gives the pressure a chance to build. So, in my view, I'm left with one of two things:
1. Replace fuel filter due to clogging (perhaps new cell had something in it). But more likely:
2. Fuel pump was somewhat challenging to get all the way down into the cell when I put it in (as if the new cell was about 1/2" to shallow). Perhaps need to remove cell and reinstall pump.

Comments? Anyone know the fuel pump part number and fuel filter part number? Is it same as 95 Cobra?

Thanks! Mark

 

[svtguy]

OK, installed the fuel pressure gauge and here's what happened:
Prior to turning the ignition on, pressure read zero. Turned ignition on; gauge began a VERY slow climb to about 4 PSIG, started car, stumbled and ran rough as before. Car would take fuel and rev OK. Gauge took about 1 to 1.5 minutes to climb to 37 PSIG. Revving the car a bit sped up the process. So, that explains why it runs better when warm: gives the pressure a chance to build. So, in my view, I'm left with one of two things:
1. Replace fuel filter due to clogging (perhaps new cell had something in it). But more likely:
2. Fuel pump was somewhat challenging to get all the way down into the cell when I put it in (as if the new cell was about 1/2" to shallow). Perhaps need to remove cell and reinstall pump.

Comments? Anyone know the fuel pump part number and fuel filter part number? Is it same as 95 Cobra?

Thanks! Mark

#1 Yes

and

#2 Yes


Paul.

 

[StillIntense]

Thanks Paul, I was afraid that you were going to say that. Damn it, now I have to drop that cell again. I was smart enough (for once) to just walk away from it for today.
Do you know what part numbers these are? Same as standard 95 Cobra?

 

[Robert M]

Thanks Paul, I was afraid that you were going to say that. Damn it, now I have to drop that cell again. I was smart enough (for once) to just walk away from it for today.
Do you know what part numbers these are? Same as standard 95 Cobra?

Mine was the same fuel filter as the 95 Cobra. I believe it was a FG-800A Motorcraft.

Yes, dropping that cell is "Fun".

R

 

[StillIntense]

Got it, thanks.
The more that I think about it, I'll bet that somehow the pickup on the bottom of the pump is blocked. I had to turn the pump in the cell around a bit to find a spot where it would go all the way down and seat on the top of the cell. I'll replace the filter first though and see if that fixes things. Should get to it later this week or next weekend.
Thanks for the advice all!

 

[93SVTCobra]

What happens if you cycle the key a few times? Does the pressure build?

Once the car is running and you do a simulated 1/4 mile run does the pressure start to drop towards the top end? That would tell me there is a restriction in the system.

I'd definitely replace the fuel filter if it hasn't been replaced recently. It's cheap and easy to do.

Lastly I'd check to make sure you aren't pinching the fuel line that runs from the fuel pump to the fuel filter.

 

[StillIntense]

Thanks Mark. When cycling ignition to "On", 4-5 times, only get about 5 PSIG. Can then start the car, after which pressure builds slowly (about 1 minute) to 37 PSIG. According to my records, that's within the limits.
I don't believe that the line is pinched, I can see most of it and was careful when putting the cell back up. Also bought a new filter today and will try that first to see if it fixes the problem. If not, down comes the cell and out comes the pump for a check.

Mark, per our prior agreement, you should have received something in the mail from me late last week. Did you?
Mark

 

[ac427cobra]

Thanks Mark. When cycling ignition to "On", 4-5 times, only get about 5 PSIG. Can then start the car, after which pressure builds slowly (about 1 minute) to 37 PSIG. According to my records, that's within the limits.
I don't believe that the line is pinched, I can see most of it and was careful when putting the cell back up. Also bought a new filter today and will try that first to see if it fixes the problem. If not, down comes the cell and out comes the pump for a check.

Mark, per our prior agreement, you should have received something in the mail from me late last week. Did you?
Mark

I have seen where the screened inlet to the pump, which is inside the sock, was clogged with debris.

FWIW

:thumbsup::coolman::beer:

 

[93SVTCobra]

Yes I did. I sent you a PM a few days ago about it.

It definitely sounds like you have a restriction as my car (and pretty much every other one I have seen) goes to around 35-40 PSI after 1-2 cycles of the key and/or immediately after you start it.

 

[StillIntense]

Never received a PM. Last one that I have from you is dated 7/23. Really looking forward it!

Thanks for the advice on the fuel pressure issue. I'm putting on a new filter tonight. If that doesn't fix things then I'll just drop the cell a few inches to check on the lines. If nothing is crimped, then the thing will to all the way to the floor....

 

[ac427cobra]

Never received a PM. Last one that I have from you is dated 7/23. Really looking forward it!

Thanks for the advice on the fuel pressure issue. I'm putting on a new filter tonight. If that doesn't fix things then I'll just drop the cell a few inches to check on the lines. If nothing is crimped, then the thing will to all the way to the floor....

When you take your filter off, see if you can blow through it. If not, that could be your problem! :shrug:

 

[Cobra R Man]

Yes I did. I sent you a PM a few days ago about it.

It definitely sounds like you have a restriction as my car (and pretty much every other one I have seen) goes to around 35-40 PSI after 1-2 cycles of the key and/or immediately after you start it.

Mark,

I had a low press. issue with my '93 Lightning. It only happened with one pump. When I was cranking it over, the press. gauge bounced up-down until it started. The next day, I had the other pump on, and when I turned the key on the press went to 37#, and started up without spinning over. Also, when driving, if I was using the (weak) pump, if I wanted to pass someone(imagine that), half way through, the truck would fall on it's face. That didn't happen when using the other pump. I changed the pump and solved problem. After I replaced the pump, when I turned the key on, the gauge would jump to 37psi. The truck was about 8yrs. old, and 60K miles at the time. Now it has 101K and still has the original pump in the other tank. Woops, shouldn't have said that. I'll probably be replacing it soon, now that it's been mentioned.

All my EFI vehicles press. jumps to 35-37psi when the key is first turned on without starting, or without cycling. Is this normal?

 

[Slow95Cobra]

Mark,

I had a low press. issue with my '93 Lightning. It only happened with one pump. When I was cranking it over, the press. gauge bounced up-down until it started. The next day, I had the other pump on, and when I turned the key on the press went to 37#, and started up without spinning over. Also, when driving, if I was using the (weak) pump, if I wanted to pass someone(imagine that), half way through, the truck would fall on it's face. That didn't happen when using the other pump. I changed the pump and solved problem. After I replaced the pump, when I turned the key on, the gauge would jump to 37psi. The truck was about 8yrs. old, and 60K miles at the time. Now it has 101K and still has the original pump in the other tank. Woops, shouldn't have said that. I'll probably be replacing it soon, now that it's been mentioned.

All my EFI vehicles press. jumps to 35-37psi when the key is first turned on without starting, or without cycling. Is this normal?

yes

 

[StillIntense]

Thanks again all, for the advice and experience.
Changed the filter today (cheap fix at 21 bucks). Replaced in 10 minutes, but no change in situation with fuel pressure. (After starting it runs up to 37-38 psig in about 45 seconds). Checked pressure regulator vacuum; all normal there.
Lowered the cell a few inches without disconnecting anything: no fuel lines crimped/crushed or bent. Of note, my Haynes manual states to check for fuel pump operation by listening at filler neck with cap off; at low pressure (when pump should have been running) couldn't hear a darn thing.
Buying a new pump tomorrow; if I'm taking the old one out to inspect it, then I'm going to replace it. I'll try and get the new one in tomorrow night.
Gene, your comments particularly helpful, thanks. Mark