20 psi Fuel pressure

Tweeternpi · Mar 19, 2006

Ok, I have been trying to get my XJ to run right. I check the fuel pressure today and all I got was 20 psi. That was with the Vac line or off did not matter. Also as soon as I turned it off the pressure would drop to Zero. Now in the passed month or so I have replaced the pump, filter and Regulator. But with it droping at turn off and only getting to 20 psi. I am thinking something is going on with the pump. I did not replace the hose in the tank that goes from the pump to the tube for the feed line. Could this be bad and leaking back into the tank?

I am going to look at it tomorrow. Anyother info would be great.

Thanks.

corbinafly · Mar 19, 2006

I would think that if you're only getting 20 psi while the motor is running and it makes no difference if the vacuum to the regulator is on or off then it would be the regulator. Did you accidentally damage the o-rings while installing the new regulator?

Kyung

JerryV · Mar 19, 2006

Tweeternpi said:
I did not replace the hose in the tank that goes from the pump to the tube for the feed line. Could this be bad and leaking back into the tank?

Thanks.

Does it spit and sputter when you try to pick up speed to fast or step on it?

I had the same problem and I changed the hose and it fixed the problem. The hose on mine was really obvious that it was leaking by, it had large cracks.

HTH, Jerry

langer1 · Mar 19, 2006

Tweeternpi said:
Ok, I have been trying to get my XJ to run right. I check the fuel pressure today and all I got was 20 psi. That was with the Vac line or off did not matter. Also as soon as I turned it off the pressure would drop to Zero. Now in the passed month or so I have replaced the pump, filter and Regulator. But with it droping at turn off and only getting to 20 psi. I am thinking something is going on with the pump. I did not replace the hose in the tank that goes from the pump to the tube for the feed line. Could this be bad and leaking back into the tank?

I am going to look at it tomorrow. Anyother info would be great.

Thanks.

What engine? and year

Tweeternpi · Mar 19, 2006

Sorry it is a 92 4.0L Auto.

And yes When I try to step on it or give it any kind of gas it spits and sputters. That is the same problem I have. I am going to go outside after I eat to pull the pump again.

XJING · Mar 19, 2006

I did this and it worked for me. I was havign the same problems. (This BMW Check Valve keeps the pressure up to stock specs) You can insert a bmw inline check valve just after fuel line exits the tank as a cheap fix. Here is some old info I got from this forum yrs ago and I don't recall the author.

“The BMW fuel check valve part number 16 14 9 068 988 fits between the filter and the fuel rail since its connections match this section of fuel hose. I installed one a couple days ago and it works fine. The unit comes with about a foot of 8mmx13mm fuel line, hose clamps, insulation and plastic nut covers for $3-5. It is necessary to make room for the valve, but that is not hard. Call a BMW dealer and order one, or it may be in stock.”

langer1 · Mar 19, 2006

Tweeternpi said:
Sorry it is a 92 4.0L Auto.

And yes When I try to step on it or give it any kind of gas it spits and sputters. That is the same problem I have. I am going to go outside after I eat to pull the pump again.

Check the little hose in the tank and make sure you have the correct pump.
You should have 31# and 47# with the vac line off. You may also want to check your ballast resistor.

corbinafly · Mar 19, 2006

langer1 said:
Check the little hose in the tank and make sure you have the correct pump.
You should have 31# and 47# with the vac line off. You may also want to check your ballast resistor.

I don't think there is a ballast resistor on OBDI vehicles.

Kyung

langer1 · Mar 19, 2006

corbinafly said:
I don't think there is a ballast resistor on OBDI vehicles.

Kyung

Should be the wiring diagrams show one.

Tweeternpi · Mar 19, 2006

Well it was that little hose in the tank. It was bad. Replaced it and now it runs great. Thanks for all the help.

Tweeternpi

corbinafly · Mar 19, 2006

langer1 said:
Should be the wiring diagrams show one.

I don't have one on my 95. No mention of one in my FSM either. I think they're for renix only.

Kyung

corbinafly · Mar 19, 2006

Tweeternpi said:
Well it was that little hose in the tank. It was bad. Replaced it and now it runs great. Thanks for all the help.

Tweeternpi

Glad you found the problem.

Kyung

langer1 · Mar 20, 2006

corbinafly said:
I don't have one on my 95. No mention of one in my FSM either. I think they're for renix only.

Kyung

Here's a 93

corbinafly · Mar 20, 2006

langer1 said:
Here's a 93

Interesting. Is that from a factory FSM?

Kyung

langer1 · Mar 20, 2006

Sure is.

corbinafly · Mar 20, 2006

langer1 said:
Sure is.

Thanks. Good to know and something else to try to remember.
I wonder what year they stopped using them.
:dunno:
Kyung

20 psi Fuel pressure

Tweeternpi

NAXJA Forum User

corbinafly

"Mmmm. More please."

JerryV

NAXJA Forum User

langer1

NAXJA Forum User

Tweeternpi

NAXJA Forum User

XJING

NAXJA Forum User

langer1

NAXJA Forum User

corbinafly

"Mmmm. More please."

langer1

NAXJA Forum User

Tweeternpi

NAXJA Forum User

corbinafly

"Mmmm. More please."

corbinafly

"Mmmm. More please."

langer1

NAXJA Forum User

corbinafly

"Mmmm. More please."

langer1

NAXJA Forum User

corbinafly

"Mmmm. More please."

Similar threads