CrossFire TBI problem
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
CrossFire TBI problem
We've owned our 82 since 87, second owner, 52,000 miles, and trouble free until recently. Started running rough and ended up having it towed home. Symptoms were similar to others I've read about a failing fuel pump so ordered a stainless steel OEM from RockAuto (http://www.rockauto.com/catalog/more...nid=301&jpid=0). Original was a rusted mess and assumed the new one would solve my problem. New pump installed, barely runs, only the passenger side injector primes and shoots fuel. Put a pressure gauge on with new pump and indicates zero pressure while running. Checked for stored codes--none! Called RockAuto, ordered a second pump, installed, and no change! Any ideas?
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
Brand new fuel filter; borrowed a fuel pressure gauge testing unit from Autozone and placed the gauge via a T fitting where the fuel filter goes.
I asked myself the same question; obviously getting some pressure but not enough to register?
Plan on trying a different gauge from another Autozone.
Maybe a poor ground and pump isn't getting 12 volts?
Instructor
Joined: Jun 2015
Posts: 221
Likes: 13
From: Central Virginia
If you hear your pump singing along happily then I would suspect a flu blockage between the fuel pump and the fuel filter. Could it be probable that your pump is not correctly wired?
You can also remove the fuel pump and verify 12 VDC at the furl pump.
I believe that the reason why your driver's side TBI is not getting fuel is like you said. Low fuel pressure.
You can also remove the fuel pump and verify 12 VDC at the furl pump.
I believe that the reason why your driver's side TBI is not getting fuel is like you said. Low fuel pressure.
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
If you hear your pump singing along happily then I would suspect a flu blockage between the fuel pump and the fuel filter. Could it be probable that your pump is not correctly wired?
You can also remove the fuel pump and verify 12 VDC at the furl pump.
I believe that the reason why your driver's side TBI is not getting fuel is like you said. Low fuel pressure.
You can also remove the fuel pump and verify 12 VDC at the furl pump.
I believe that the reason why your driver's side TBI is not getting fuel is like you said. Low fuel pressure.
Both 3 amp fuses are good for the injectors.
I've got an ohmmeter but not sure how to check for 12 VDC.
Safety Car
Joined: Oct 2008
Posts: 4,022
Likes: 30
From: Los Angeles CA
wild guess , rebuild your TB's
driver's tb get's fuel first not second, fuel return line attached to the pass tb
you should get a 85-87 pump, woefully inadequate is the stock pump
how was the sock? if it disintegrate in your gas tank and you ran it without the filter to check pressure, you just shot all they debris into the nozzles
you changed your filter?
driver's tb get's fuel first not second, fuel return line attached to the pass tb
you should get a 85-87 pump, woefully inadequate is the stock pump
how was the sock? if it disintegrate in your gas tank and you ran it without the filter to check pressure, you just shot all they debris into the nozzles
you changed your filter?
Last edited by slickfx3; Jan 20, 2016 at 06:15 PM.
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
wild guess , rebuild your TB's
driver's tb get's fuel first not second, fuel return line attached to the pass tb
you should get a 85-87 pump, woefully inadequate is the stock pump
how was the sock? if it disintegrate in your gas tank and you ran it without the filter to check pressure, you just shot all they debris into the nozzles
you changed your filter?
driver's tb get's fuel first not second, fuel return line attached to the pass tb
you should get a 85-87 pump, woefully inadequate is the stock pump
how was the sock? if it disintegrate in your gas tank and you ran it without the filter to check pressure, you just shot all they debris into the nozzles
you changed your filter?
Safety Car
Joined: Oct 2008
Posts: 4,022
Likes: 30
From: Los Angeles CA
New filter and sock on original factory pump was intact; never ran it without a filter other than to check the pressure and the problem was apparent prior to that. Disagree about the 85-87 pump; original factory was good enough to get 30 plus years and that's good enough for me. And I can barely hear the pump cycle on when ignition is turned on and soon thereafter ceases.
however.
you have a new 82 pump which max out at
Last edited by slickfx3; Jan 20, 2016 at 07:24 PM.
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Safety Car
Joined: Oct 2008
Posts: 4,022
Likes: 30
From: Los Angeles CA
i think you have located your problem, no fuel in the pass tb, that is where i would start looking...i think those tb have little screens in them, never had mine apart...
Last edited by slickfx3; Jan 20, 2016 at 07:25 PM.
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
Worried about the possible problems 30-40 psi might pose in a system designed for 15 psi!
Safety Car
Joined: Oct 2008
Posts: 4,022
Likes: 30
From: Los Angeles CA
if your afpr is set at 40 yes, but if it's stock it prolly set at 13.
the stock pump was know to put out a few lbs too low when new and as they aged it went down from there and idle and wot suffer, it ran lean up there, didn't give the already compromised crossfire it full potential, and we all know crossfires need help
but your issue sounds like a malfunction you can actually see, pull that TB
Last edited by slickfx3; Jan 20, 2016 at 10:21 PM.
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
Bought my own fuel pressure gauge last night so going to recheck this new second pump.
Still not getting pressure, either the line is blocked, an electrical problem, or two bad "new" pumps which I find difficult to believe!
And thanks for your continued assistance!
Melting Slicks
Joined: Mar 2006
Posts: 2,248
Likes: 67
From: Warrington PA
Finalist 2020 C4 of the Year - Unmodified
Check your lines for being blocked.....when you disconnect the fuel filter, the gas should be running freely from that line, when you switch the key on and the pump gets activated. Of course if you have a good flow there, then you may have blockage from that point up to the TB's. It's possible some dirt or particles made it past the filter and is lodged in that line preventing the TB's from getting the proper flow.
The pump will only be heard for 2 seconds after the key is turned on.
You can also check your fuel pump relay in the battery, ECM area. It might be possible that can be defective.
The pump will only be heard for 2 seconds after the key is turned on.
You can also check your fuel pump relay in the battery, ECM area. It might be possible that can be defective.
Safety Car
Joined: Oct 2008
Posts: 4,022
Likes: 30
From: Los Angeles CA
There is no fuel in the drivers TB and no pressure either in the supply fuel line prior.
Bought my own fuel pressure gauge last night so going to recheck this new second pump.
Still not getting pressure, either the line is blocked, an electrical problem, or two bad "new" pumps which I find difficult to believe!
And thanks for your continued assistance!
Bought my own fuel pressure gauge last night so going to recheck this new second pump.
Still not getting pressure, either the line is blocked, an electrical problem, or two bad "new" pumps which I find difficult to believe!
And thanks for your continued assistance!
you can separate the blockage either to the engine or to the gas tank
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
I think I've found at least part of my problem; only 8 VDC at the 3 pin connector that plugs into the fuel pump. And yes the battery is fully charged. Not electrical smart so any help in tracking this down is appreciated!
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
Checked fuel pressure at the pump outlet: 20 psi.
Blew the line out both directions and pressure at filter location via T fitting: 14 psi.
6 psi drop between pump and filter?
Thinking the problem is at the TB like many have suggested!
Blew the line out both directions and pressure at filter location via T fitting: 14 psi.
6 psi drop between pump and filter?
Thinking the problem is at the TB like many have suggested!
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
wild guess , rebuild your TB's
driver's tb get's fuel first not second, fuel return line attached to the pass tb
you should get a 85-87 pump, woefully inadequate is the stock pump
how was the sock? if it disintegrate in your gas tank and you ran it without the filter to check pressure, you just shot all they debris into the nozzles
you changed your filter?
driver's tb get's fuel first not second, fuel return line attached to the pass tb
you should get a 85-87 pump, woefully inadequate is the stock pump
how was the sock? if it disintegrate in your gas tank and you ran it without the filter to check pressure, you just shot all they debris into the nozzles
you changed your filter?
The pass TB gets fuel first, fuel return line attached to the driver's TB.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
I would be more concerned IF you were getting the fuel pump to turn back on when you crank the engine AFTER the initial TWO SECOND PRIME that occurs when you turn the key on. AND YES....making sure that you have 12 volts going to the pump is VERY IMPORTANT...obviously.
DUB
Thread Starter
Intermediate
Joined: Jan 2007
Posts: 47
Likes: 0
From: Birmingham AL
