Fuel pump failure??
Discussion
Hi Chaps
I'm after some more advice...
Had to bring the 98 Griff 500 home on back of a AAA truck again at the weekend!
I'm not sure what the issue is and would be grateful for any ideas/advice you knowledgeable types could offer.
I had noticed a small amount of hesitation/fluffyness at low rpm a couple of times the last time I drove the car (on Saturday), but put that down to the heavy 'start/stop' traffic I was in at the time. But on Sunday afternoon it started running quite rough, no backfiring, but would not accelerate, this got worse and after about 1/2 mile of stuttering it finally cut out and would not restart.
I do have a spark, so was wondering if it could be a fuel issue, pump failure?
Can anyone help with suggestions what I should try next to diagnose the issue?
As always TIA chaps
Cheers
Jon
I'm after some more advice...
Had to bring the 98 Griff 500 home on back of a AAA truck again at the weekend!
I'm not sure what the issue is and would be grateful for any ideas/advice you knowledgeable types could offer.
I had noticed a small amount of hesitation/fluffyness at low rpm a couple of times the last time I drove the car (on Saturday), but put that down to the heavy 'start/stop' traffic I was in at the time. But on Sunday afternoon it started running quite rough, no backfiring, but would not accelerate, this got worse and after about 1/2 mile of stuttering it finally cut out and would not restart.
I do have a spark, so was wondering if it could be a fuel issue, pump failure?
Can anyone help with suggestions what I should try next to diagnose the issue?
As always TIA chaps
Cheers
Jon
If you can hear the fuel pump, do you still have the plug extender? Mine were dead and the symptoms were like yours, once a bit hot, the car was hesitating a lot, power was missing until the engine died. And once cold again, it was able to restart but for a short period.
I've managed to go back home but with multiple stops (not sure I was able to do 1 mile without stalling).
I've managed to go back home but with multiple stops (not sure I was able to do 1 mile without stalling).
Thanks for the input chaps
I can hear the fuel pump prime when I try to start, does that rule out the 2 relays in the passenger footwell?
"do you still have the plug extender?" what is the plug extender? Symptoms seem same as zeb74 but worse, will not run at all now.
If I can hear the pump priming does that mean it's not the pump, or could it be the pump has failed but still making noise?
I can hear the fuel pump prime when I try to start, does that rule out the 2 relays in the passenger footwell?
"do you still have the plug extender?" what is the plug extender? Symptoms seem same as zeb74 but worse, will not run at all now.
If I can hear the pump priming does that mean it's not the pump, or could it be the pump has failed but still making noise?
If pump primes that normally suggests it and it’s corresponding relay are working.
Extenders are the metal end sections connected to your HT leads that directly fit over the plugs.
These can be problematic and cause poor or no spark but rarely all 8 will fail. Often they have been removed.
The symptoms for that would usually be a misfire but not normally enough to actually stop engine running.
You can check you have fuel pressure by putting a gauge on the valve which sits on the r/h side of fuel rail. Or you can be brave and using a big cloth rag simply depress the valve with screwdriver and fuel should come out under pressure. The valve itself is exactly the same type as fitted to your tyres and should have a dust cap fitted exactly as your tyres do.
Is there a strong smell of fuel in engine bay after attempting to start it? The engine might have flooded by now so its actually a good idea to remove all your plugs and clean or replace them. With plugs removed it’s now a good idea to turn engine over using a strong battery with fuel pump disconnected and throttle set to wide open. This will help rebuild some compression if the bores have been washed.
You can disconnect the pump by simply pulling a wire off it.
It’s also now a good time to check you have a spark at each plug which will help to confirm if any extenders or other ignition components are faulty. In fact do this part before worrying about fuel pressure.
Come back with the results.
Extenders are the metal end sections connected to your HT leads that directly fit over the plugs.
These can be problematic and cause poor or no spark but rarely all 8 will fail. Often they have been removed.
The symptoms for that would usually be a misfire but not normally enough to actually stop engine running.
You can check you have fuel pressure by putting a gauge on the valve which sits on the r/h side of fuel rail. Or you can be brave and using a big cloth rag simply depress the valve with screwdriver and fuel should come out under pressure. The valve itself is exactly the same type as fitted to your tyres and should have a dust cap fitted exactly as your tyres do.
Is there a strong smell of fuel in engine bay after attempting to start it? The engine might have flooded by now so its actually a good idea to remove all your plugs and clean or replace them. With plugs removed it’s now a good idea to turn engine over using a strong battery with fuel pump disconnected and throttle set to wide open. This will help rebuild some compression if the bores have been washed.
You can disconnect the pump by simply pulling a wire off it.
It’s also now a good time to check you have a spark at each plug which will help to confirm if any extenders or other ignition components are faulty. In fact do this part before worrying about fuel pressure.
Come back with the results.
Edited by Classic Chim on Wednesday 2nd August 07:26
The extenders fit on the plugs to help take the leads away from the heat, they are a common failure point.
Most remove them and fit the leads direct to plugs but this brings its own problems as the leads are closer to the manifolds.
It does sound more like an ignition problem though so id maybe try removing the extenders first for test purposes if your car has them.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Most remove them and fit the leads direct to plugs but this brings its own problems as the leads are closer to the manifolds.
It does sound more like an ignition problem though so id maybe try removing the extenders first for test purposes if your car has them.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
My Griff developed a misfire last year and it was one of the plug extenders, a later replacement (shiny), the original genuine BERU ones seem to last a lot longer. 
This didn't cause to stall however, it would run on 7, but was pushing unburnt fuel into the exhaust. 
In my case, it was easy to diagnose with a multimeter as it had gone open circuit. But if you have one breaking down with higher voltages when hot, this may not show itself. I removed them from cylinders 1 and 2 (leads not so close to the manifolds at the front of the engine), used one on no 6 (the knackered one), leaving me with a spare.
This didn't cause to stall however, it would run on 7, but was pushing unburnt fuel into the exhaust. In my case, it was easy to diagnose with a multimeter as it had gone open circuit. But if you have one breaking down with higher voltages when hot, this may not show itself. I removed them from cylinders 1 and 2 (leads not so close to the manifolds at the front of the engine), used one on no 6 (the knackered one), leaving me with a spare.
First thing I ditched when I bought my Chimaera was the plug extensions. Horrible things. I fitted socks over the HT leads to insulate against the manifold heat. No problems here.
I agree with the others though, more likely ignition than pump especially if you can hear it prime.
How old is your coil and dizzy cap/rotor arm? Always worth replacing cap and arm as a tiny invisible crack will cause arcing and no spark.
I agree with the others though, more likely ignition than pump especially if you can hear it prime.
How old is your coil and dizzy cap/rotor arm? Always worth replacing cap and arm as a tiny invisible crack will cause arcing and no spark.
I do have the plug extenders still fitted, and they are pretty horrible, going to replace them.
Having said that, I checked for spark again and I am definitely getting a spark. Plugs were a bit 'sooty' but I suppose that would not be surprising given the issues I'm getting.
With regard to the fuel pressure, can I use a tire pressure gauge on the little valve on the fuel rail, or would that be a bad idea? Also, what sort of pressure rage should I be getting with a functioning fuel pump?
Having said that, I checked for spark again and I am definitely getting a spark. Plugs were a bit 'sooty' but I suppose that would not be surprising given the issues I'm getting.
With regard to the fuel pressure, can I use a tire pressure gauge on the little valve on the fuel rail, or would that be a bad idea? Also, what sort of pressure rage should I be getting with a functioning fuel pump?
I would only use a gauge suitable for fluids.
Test procedure here.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Test procedure here.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
If its the same as a Chim it will be this one from memory, only difference being the terminals.
Bosch pumps are readily available too at roughly £90.
https://www.ebay.co.uk/itm/224855610019?mkcid=16&a...
Just make sure your filter isn't blocked and fuel hoses are in good condition as they can collapse internally.
Bosch pumps are readily available too at roughly £90.
https://www.ebay.co.uk/itm/224855610019?mkcid=16&a...
Just make sure your filter isn't blocked and fuel hoses are in good condition as they can collapse internally.
Sounds like a silly question but have you checked fuel pump wiring is good and did you hear pump prime before checking fuel rail pressure?
For your info…. Voltage drop from a poor contact in the wiring ( usually ) around door pillar where there is a connector point has often been the reason for poor pump performance.
Fuel pumps are possibly the single most reliable part on these cars and rarely fail so just be sure everything else is good before buying a new one.
Conversely the fuel filter must be one of the hardest parts to replace on these cars and why they are often overlooked. If you are buying a new pump so draining the system down it’s the right time to change rubber hoses and filter at the back of the car. If you live in hot climbs this and replacement of the front rubber fuel lines especially becomes an item to be checked regularly.
If the car has been fitted with the correct R9 lines they may last longer but still check them regularly.
For your info…. Voltage drop from a poor contact in the wiring ( usually ) around door pillar where there is a connector point has often been the reason for poor pump performance.
Fuel pumps are possibly the single most reliable part on these cars and rarely fail so just be sure everything else is good before buying a new one.
Conversely the fuel filter must be one of the hardest parts to replace on these cars and why they are often overlooked. If you are buying a new pump so draining the system down it’s the right time to change rubber hoses and filter at the back of the car. If you live in hot climbs this and replacement of the front rubber fuel lines especially becomes an item to be checked regularly.
If the car has been fitted with the correct R9 lines they may last longer but still check them regularly.
Thanks for the input, where is the fuel filter located?
I haven't been under the car for a while I have never looked at the fuel lines, do they run mainly exposed?
Are the very difficult to replace?
I would assume if you were going to replace part of the fuel line you would just replace the whole complete run right?
I haven't been under the car for a while I have never looked at the fuel lines, do they run mainly exposed?
Are the very difficult to replace?
I would assume if you were going to replace part of the fuel line you would just replace the whole complete run right?
Thanks Bud. O/P the chap above knows all about the fuelling system 
You will need a ramp or axle stands to inspect properly.
Fuel pump is bolted to l/h bottom chassis rail right at the back of the car and directly connected to tank via a short fuel line. You will notice the wiring to it.
Follow rubber fuel hose from pump and you will see a canister type filter bolted via a small bracket to the chassis sort of up and inside Diff carrier area.
In essence it’s quite simple to remove that bracket and release the filter but access is very restricted and I’d always advise using penetrating oil a few days before attempting to undo that bolt.
Unless you are proficient at such mechanical work my advice is use a good mechanic who’s used to older or bespoke vehicles who has a ramp as access to both the metal sections of fuel line and rubberised hose is ideally from below and require both arms to go up and around gearbox to gain access to the retaining clips for front sections of rubber hose to be removed.
As the fuel system is constantly cycling fuel at pressure you also have the same deal with replacing the return lines back to tank on the r/h lower chassis rail.
A good Tvr man can do this job in a few hours given a fair dose of luck but it’s a ball ache to be honest so can take many hours to do properly.
Usually the metal sections of pipe fair well and not often badly corroded but will require close inspection.
Anyway I’d concentrate on one thing at a time and actually answering some of our questions might get you closer to your fuel issue problems!
Can you just confirm you have a full battery and when you turn ignition on and before you crank engine you can hear a whirring noice for usually 2-3 seconds then stop. That noise should be coming from the rear l/h side of the car and is the fuel pump priming the system upto pressure.
If it does prime then stop, check fuel rail pressure at this point. If you have already done this in that order I apologise.
If you can’t hear the pump prime you firstly need to check it’s getting electricity.
It could just be a loose wire at the pump.
You will need a ramp or axle stands to inspect properly.
Fuel pump is bolted to l/h bottom chassis rail right at the back of the car and directly connected to tank via a short fuel line. You will notice the wiring to it.
Follow rubber fuel hose from pump and you will see a canister type filter bolted via a small bracket to the chassis sort of up and inside Diff carrier area.
In essence it’s quite simple to remove that bracket and release the filter but access is very restricted and I’d always advise using penetrating oil a few days before attempting to undo that bolt.
Unless you are proficient at such mechanical work my advice is use a good mechanic who’s used to older or bespoke vehicles who has a ramp as access to both the metal sections of fuel line and rubberised hose is ideally from below and require both arms to go up and around gearbox to gain access to the retaining clips for front sections of rubber hose to be removed.
As the fuel system is constantly cycling fuel at pressure you also have the same deal with replacing the return lines back to tank on the r/h lower chassis rail.
A good Tvr man can do this job in a few hours given a fair dose of luck but it’s a ball ache to be honest so can take many hours to do properly.
Usually the metal sections of pipe fair well and not often badly corroded but will require close inspection.
Anyway I’d concentrate on one thing at a time and actually answering some of our questions might get you closer to your fuel issue problems!
Can you just confirm you have a full battery and when you turn ignition on and before you crank engine you can hear a whirring noice for usually 2-3 seconds then stop. That noise should be coming from the rear l/h side of the car and is the fuel pump priming the system upto pressure.
If it does prime then stop, check fuel rail pressure at this point. If you have already done this in that order I apologise.
If you can’t hear the pump prime you firstly need to check it’s getting electricity.
It could just be a loose wire at the pump.
Edited by Classic Chim on Monday 7th August 07:55
Edited by Classic Chim on Monday 7th August 07:56
Thanks for the reply CC, much appreciated!
I did mention I could here the pump prime when Belle427 and Zeb74 asked about it. I can hear the pump prime for about 3 secs as you describe. I do hear a similar buzzing type noise coming from the right side of the engine bay (throttle body/air intake side) when the ignition is turned off, slightly shorter duration (about 1 or 2 secs), not sure what that's all about. The battery is fully charged and strong.
Your description and guidance is perfect, exactly what I needed.
I have sprayed the pump and around the filter with lots of WD 40, I'll leave that to soak for a while, I'm not sure how I'm going to proceed from there yet. I'm thinking I might see if I can replace the pump and filter, then get it running so I can get it to someone with a ramp and much better mechanical experience/skills than mine to replace the rubber fuel flow and return lines.
If I get into trouble before then, which is quite likely! I'll put it on a trailer and get it to someone who can fix it...
I did mention I could here the pump prime when Belle427 and Zeb74 asked about it. I can hear the pump prime for about 3 secs as you describe. I do hear a similar buzzing type noise coming from the right side of the engine bay (throttle body/air intake side) when the ignition is turned off, slightly shorter duration (about 1 or 2 secs), not sure what that's all about. The battery is fully charged and strong.
Your description and guidance is perfect, exactly what I needed.
I have sprayed the pump and around the filter with lots of WD 40, I'll leave that to soak for a while, I'm not sure how I'm going to proceed from there yet. I'm thinking I might see if I can replace the pump and filter, then get it running so I can get it to someone with a ramp and much better mechanical experience/skills than mine to replace the rubber fuel flow and return lines.
If I get into trouble before then, which is quite likely! I'll put it on a trailer and get it to someone who can fix it...
JonTribe said:
Thanks for the reply CC, much appreciated!
I did mention I could here the pump prime when Belle427 and Zeb74 asked about it. I can hear the pump prime for about 3 secs as you describe. I do hear a similar buzzing type noise coming from the right side of the engine bay (throttle body/air intake side) when the ignition is turned off, slightly shorter duration (about 1 or 2 secs), not sure what that's all about..
That noise on ignition off is the stepper motor driving back to its datum position, completely normal. I did mention I could here the pump prime when Belle427 and Zeb74 asked about it. I can hear the pump prime for about 3 secs as you describe. I do hear a similar buzzing type noise coming from the right side of the engine bay (throttle body/air intake side) when the ignition is turned off, slightly shorter duration (about 1 or 2 secs), not sure what that's all about..
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