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Discussion Starter · #1 ·
Ok, I am back at it already. After driving my 1973 Volvo 164 with a Delphi fuel pump three pumps, I now have to switch out fuel pumps again. It has very poor acceleration and it always does "great" whenever I switch fuel pumps, but after a few short drives, the same sluggish behavior reappears. I know it is the fuel because when it gets sluggish, I have to throttle the gas to make it go better, and it usually results in backfire through the tailpipe. I now have a remanufactured Bosch fuel pump that is OEM. I will try to switch out pumps tomorrow. Can anyone offer any other ideas? Is anyone interested in a excellent condition white with original light blue interior Volvo? I think I am at my wits end on this.
 

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What does your fuel pressure test out at when you have sluggish behaviour? If it remains at 28 - 30 psi, then the problem is not with the pump and the fuel supply system up to the injectors. If the pressure is dropping below 28 psi, then maybe you still have a contamination issue which is plugging up the supply lines, clogging your pumps or damaging your pumps.
 

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Discussion Starter · #4 · (Edited)
What does your fuel pressure test out at when you have sluggish behaviour? If it remains at 28 - 30 psi, then the problem is not with the pump and the fuel supply system up to the injectors. If the pressure is dropping below 28 psi, then maybe you still have a contamination issue which is plugging up the supply lines, clogging your pumps or damaging your pumps.
The pressure remains a constant 32PSI no matter what.

The problem is the fuel pump seems to suffer a premature death. One hypothesis is the fuel pumps, Airtex and Delphi are junk. Another hypothesis is the fuel pump is getting too much juice. Does anyone know what the current reading should be to the fuel pump for a 1973 164?
 

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Discussion Starter · #5 ·
And, have you fully checked the ignition, timing, points, etc, and valve clearances?
I switched to the 123Ignition electronic ignition a couple of months ago. Even with the new ignition system, the car runs like it always has. The timing is correct, however, I have not checked the clearances.
 

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It's a 12 volt dc pump in a 12 volt dc car correct?
So how would it get "too much juice" ?
If it was getting too much voltage you'd be talking about exploding batterys too.

Is the fuel filter getting plugged ? The tank is venting ok?

Is your new ignition wired right? Had a VW that ran great until I turned the headlights on. Turned out a "mechanic" rigged the wiring to bypass a relay.
 

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Discussion Starter · #7 ·
It's a 12 volt dc pump in a 12 volt dc car correct?
So how would it get "too much juice" ?
If it was getting too much voltage you'd be talking about exploding batterys too.

Is the fuel filter getting plugged ? The tank is venting ok?

Is your new ignition wired right? Had a VW that ran great until I turned the headlights on. Turned out a "mechanic" rigged the wiring to bypass a relay.
12v car with a 12v pump. I just wondered if the ECU might be sending erroneous inpuits that might result in too much current sent.

The wiring on the new ignition looks correct. The fuel pump death spiral predated the new ignition.

Ok, how do you know if the tank is venting properly? Thanks.

Steve
 

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Discussion Starter · #8 ·
It's a 12 volt dc pump in a 12 volt dc car correct?
So how would it get "too much juice" ?
If it was getting too much voltage you'd be talking about exploding batterys too.

Is the fuel filter getting plugged ? The tank is venting ok?

Is your new ignition wired right? Had a VW that ran great until I turned the headlights on. Turned out a "mechanic" rigged the wiring to bypass a relay.

Just so you know, I plan to install an OEM remanufactured Bosch pump as a replacement for my failing Delphi pump. I wanted to see if there were any other possibilities other than these Delphi and Airtex pumps were just junk. Also, my dash brake light and parkinbg light are both on and I cannot get them to turn off. At one time, I could be simply playing with the parking brake handle. No more. I researched some old Swedespeed posts and there is some discussion that these lights are on because of either a faulty voltage regulator and/or alternator. Excuse my ignorance, my mechanical experience only goes so far, but could a faulty voltage regulator and/or alternator be causing power issues with the fuel pump? Maybe sending spikes which shorten the lifespan?
 

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The pressure remains a constant 32PSI no matter what.

The problem is the fuel pump seems to suffer a premature death. One hypothesis is the fuel pumps, Airtex and Delphi are junk. Another hypothesis is the fuel pump is getting too much juice. Does anyone know what the current reading should be to the fuel pump for a 1973 164?
32 psi is a bit high for the Djet; but, not a disaster. Early Djet ran at 28 psi and later ones (don't know the transition year) ran at 30 psi.

When the pumps fail, does the motor fail (completely stops running) or is the pump unable to provide the required pressure? If its because the pump is unable to provide the required pressure and you are confident that the fuel filter and lines are not blocked, then the pump mechanicals may be suffering from high wear rates. The pump could be sucking up garbage from the tank if the suction filter in the tank is broken or if that filter is clogged, the pump could be cavitating causing damage to the pump. When you do your fuel pump replacement, make sure that you are getting good fuel flow on the fuel pump inlet line. Fuel pumps don't like having to 'suck' to get their fuel.
 

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12v car with a 12v pump. I just wondered if the ECU might be sending erroneous inpuits that might result in too much current sent.

Steve
The ECU just controls the fuel pump relay. It is an on / off signal. If you are not burning out light bulbs and other stuff, you are not damaging the fuel pump.
 

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Also, my dash brake light and parkinbg light are both on and I cannot get them to turn off. At one time, I could be simply playing with the parking brake handle. No more. I researched some old Swedespeed posts and there is some discussion that these lights are on because of either a faulty voltage regulator and/or alternator. Excuse my ignorance, my mechanical experience only goes so far, but could a faulty voltage regulator and/or alternator be causing power issues with the fuel pump? Maybe sending spikes which shorten the lifespan?
Two places to look.

There is a switch on the parking brake handle that closes when the parking brake is applied causing the light to come on. The switch is adjustable and may have come out of adjustment and is staying closed even when the brake is released. The switch may be broken and is always staying closed. The wire to the switch may be shorting on the body some place causing the light to stay on.

There is also a brake system failure switch on the hydraulic brake system distribution block. If one of your brake circuits fails, this switch is activated causing the light to come on (I think you would have noticed that). Sometimes this switch just fails closed causing the light to come on. Get the manual and find the location of the switch to check it out.

Based upon your discription, I put money on the parking brake switch.
 

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Easiest way to make sure the tank is venting is take off the fuel cap when it starts running bad. If that clears it up that's the problem. Sometimes a clue is a sucking sound when you pull the cap.

I've seen it a couple of times were the tank vent that's supposed to go to the charcoal dohinky got hooked straight to a vacuum hose.

I don't know if that's going on here but it's real easy to check.
 

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Easiest way to make sure the tank is venting is take off the fuel cap when it starts running bad. If that clears it up that's the problem. Sometimes a clue is a sucking sound when you pull the cap.

I've seen it a couple of times were the tank vent that's supposed to go to the charcoal dohinky got hooked straight to a vacuum hose.

I don't know if that's going on here but it's real easy to check.
Good point. Somewhere along the way the 140 / 160 switched from the simple activated carbon canister to one which appears to have a control valve on it. I don't know the specifics; but, if the canister and valve arrangement is plugged that could cause fuel starvation problems.

As you point, easy to check out. If he wants to do a drive around test with the gas cap on, it would be easy to pull the tubes off the charcoal canister which should vent the tank to atmosphere if the vent line from the tank to the engine compartment is not plugged. There should also be a surge canister in the trunk which he could pull the vent line from; but, that requires removing trunk panels to get access.
 

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Discussion Starter · #14 · (Edited)
32 psi is a bit high for the Djet; but, not a disaster. Early Djet ran at 28 psi and later ones (don't know the transition year) ran at 30 psi - THE numbers I saw showed Volvo had upped the PSI from 28 to 31.2, so I moved it a wee bit higher since it ran better at 32.

When the pumps fail, does the motor fail (completely stops running) or is the pump unable to provide the required pressure? - NO. Interestingly, the engine runs fine at idle when in park when the fuel pump acts up, until it is complete failure then engine will not start. As far as I have noticed, the fuel pressure remains constant throughout. I can go star the car now without issues, until I try to drive it and it will need me to throttle the gas pedal to move. As soon as I replace the fuel pump, the car runs surprisingly well and almost like new. It quickly starts to have less performance the more I drive until I get poor performance and have difficulty getting the car to make it back to my driveway. I will be brave and try it again and then when I drive it t the car backfires through the tailpipe which has always been the telltale sign that it is the fuel pump. I have gone through 5-6 fuel pumps since May, I know the routine. I replace the fuel pump and the car runs great and I feel confident it is cured, then after a few short drives, the car starts to drive less well. It seems to be a pattern which is why I think maybe it is an electrical issue. It cou8ld be just the really sorry fuel pumps by Airtex and Delphi. Also, my Nissan 280Z fuel pump gave out quickly, too.

If its because the pump is unable to provide the required pressure and you are confident that the fuel filter and lines are not blocked - REST assured the fuel lines are free and clear. I just went through removed all of the rust from the fuel tank, fuel lines, both rubber and the fuel rail, along with replacing 6 injectors, fuel relay switch, 3 fuel fuses, verified the TPS works and is in the correct position.

The pump could be sucking up garbage from the tank if the suction filter in the tank is broken or if that filter is clogged, the pump could be cavitating causing damage to the pump - FUELl tank is extra free and clear. NO rust.

When you do your fuel pump replacement, make sure that you are getting good fuel flow on the fuel pump inlet line. Fuel pumps don't like having to 'suck' to get their fuel. - WILLl do.

See my response above. Thanks.
 

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Discussion Starter · #16 · (Edited)
Good point. Somewhere along the way the 140 / 160 switched from the simple activated carbon canister to one which appears to have a control valve on it. I don't know the specifics; but, if the canister and valve arrangement is plugged that could cause fuel starvation problems.

As you point, easy to check out. If he wants to do a drive around test with the gas cap on, it would be easy to pull the tubes off the charcoal canister which should vent the tank to atmosphere if the vent line from the tank to the engine compartment is not plugged. There should also be a surge canister in the trunk which he could pull the vent line from; but, that requires removing trunk panels to get access.
Ok, I just went outside and adjusted the PSI down a bit and checked the fittings to the charcoal dohicky. There might have a been a blockage in one of the hoses to the charcoal dohicky. Otherwise, everything checks clear. The PSI remained constant when revved. The throttle response is a wee bit better, but the fuel pump is getting close to finish. I guess I am down to the aftermarket fuel pumps sucking since everything else seems to be ok.
 

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Discussion Starter · #17 ·
Two places to look.

There is a switch on the parking brake handle that closes when the parking brake is applied causing the light to come on. The switch is adjustable and may have come out of adjustment and is staying closed even when the brake is released. The switch may be broken and is always staying closed. The wire to the switch may be shorting on the body some place causing the light to stay on.

There is also a brake system failure switch on the hydraulic brake system distribution block. If one of your brake circuits fails, this switch is activated causing the light to come on (I think you would have noticed that). Sometimes this switch just fails closed causing the light to come on. Get the manual and find the location of the switch to check it out.

Based upon your discription, I put money on the parking brake switch.
I will take a look at this tomorrow. Thanks.

Steve
 

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Bobbyz makes an excellent point, I encountered the same. when I got my 1800e there was a cut steel line underneath the car open to the air. thinking that was not good I capped it and immediately ran into the same fuel starvation issues. car would run for a few minutes then stall. The fuel pump could be heard straining hard to get fuel. then after much research discovered that was the vent line to the non existent charcoal canister. when I removed the cap it ran fine.

This is one possibility for your problem, a better test would be to remove the vent line in the trunk as suggested, to eliminate the possibility that the line is plugged somewhere between the trunk and the charcoal canister.
 
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