can a vacum line cause a fuel pressure drop from 76 lbs to 7 lbs on a 89 ford f150 laraint 4x4 ,302 fuel injected with dual tank

Asked by Aug 29, 2016 at 06:51 PM about the 1989 Ford F-150 XLT Standard Cab SB

Question type: Maintenance & Repair

bypassed my fuel line. My line starts from my tank to the the fuel pump on the
rail. Still wont run. Replaced all new parts except fuel line.

1 Answer

88,975

No, the only vacuum line even closely related to the fuel system is the one on the fuel pressure regulator, and if it was bad or missing it would cause the fuel pressure to top out as high as the fuel pump could go. Now if the fuel pressure regulator stuck in full bypass it could cause a large pressure drop but you could recover that pressure by pinching off the return fuel line. Your right in that grey area of fuel pumps, does yours have lift pumps in the tanks and 1 large pressure pump in the frame rail, or high pressure pumps in the fuel tanks? Cause 7 lbs of fuel pressure sounds like lift pump pressure, not main pump pressure.

Your Answer

Add photo

Related Questions

  • I have a 89 ford f150 xlt lareint 4x4 with dual tanks and im having fuel problems. 3 answers

    I replaced my rear fuel tank with the pump and then also the the pump on the rail and then my fuel filter and fuel regulator. I also had my fuel relay switch replaced and did a voltage test. My truc...

    1989 Ford F-150 XL Extended Cab SB

    -

    Maintenance & Repair

  • Putting a fuel injection motor into a carburetored frame. (300 six Carbed, 302 Fuel injected) 4 answers

    Alright boys and girls. I got a question. I recently bought a 86 Ford F150 w/ 300 6 cylinder. It has a lowend knock and I wanna pull the motor. Now. I got a 88 Ford F150 with a fuel injected 302. I ...

    1986 Ford F-150 XLT Standard Cab 4WD LB

    -

    Maintenance & Repair

  • 89 f150 5.0 fuel problems 6 answers

    I bought a 89 f150 cheap from a dealership had no problems for 6 months, then all of the sudden it broke down on the highway I was pushing the gas and it was slowing down when I pressed it. I've re...

    1989 Ford F-150 XLT Extended Cab LB

    -

    Maintenance & Repair

  • 1989 F150 fuel problem 1 answer

    I replaced the clutch and slave cylinder by sliding back trans, ran great for 2 days. Started running warm and sluggish. Had it scanned came up as short in ground wire to fuel pump. Fixed only short i...

    1989 Ford F-150

    -

    Maintenance & Repair

  • dual fuel tanks 1 answer

    F150 , Ford , Pick-up - eliminate the dual tank switch (302 CID, 8 Cyl, 1986)

    1986 Ford F-150

    -

    Car Customization

Search Ford F-150 Questions

Ford F-150 Experts

#1 OJ
OJ
Reputation 7,220
#2 dandyoun
dandyoun
Reputation 4,260
#3 tennisshoes
tennisshoes
Reputation 2,590
View All

Related Models For Sale

Used GMC Sierra 1500
876 Great Deals out of 64,410 listings starting at $1,500
Used Ford Mustang
320 Great Deals out of 45,523 listings starting at $2,000
Used Ford F-250
487 listings starting at $3,975
Used Ford Ranger
176 Great Deals out of 6,201 listings starting at $1,300

Used Cars For Sale

2017 Ford F-150 For Sale
3 Great Deals out of 116,980 listings starting at $18,299
2016 Ford F-150 For Sale
155 Great Deals out of 29,154 listings starting at $17,877
2015 Ford F-150 For Sale
193 Great Deals out of 7,230 listings starting at $11,600
2014 Ford F-150 For Sale
441 Great Deals out of 12,254 listings starting at $9,995