Trouble With The Griff
Discussion
It's not going very well.
I had a new Meta alarm and immobiliser fitted and it all works perfectly.
However,
1.The fuel pump carries on running when the ignition is on, and appears not to come up to pressure. I suspect the regulator is to blame, so I will replace it tomorrow.
2.Initially there was a lack of sparks, but Johno came to the rescue with a new ignition amp module.
3.most worryingly number one and two injectors are firing constantly when the ignition is on, even though the engine isn't running! Why?
I could do with an ECU wiring diagram, as the bible is a little sparse on these details. Would any one have something to help?
Also, with no run sensor on the crank, what is the ECU taking as a reference for injector logic?
Mr Disappointed
I had a new Meta alarm and immobiliser fitted and it all works perfectly.
However,
1.The fuel pump carries on running when the ignition is on, and appears not to come up to pressure. I suspect the regulator is to blame, so I will replace it tomorrow.
2.Initially there was a lack of sparks, but Johno came to the rescue with a new ignition amp module.
3.most worryingly number one and two injectors are firing constantly when the ignition is on, even though the engine isn't running! Why?
I could do with an ECU wiring diagram, as the bible is a little sparse on these details. Would any one have something to help?
Also, with no run sensor on the crank, what is the ECU taking as a reference for injector logic?
Mr Disappointed
The fact that you have a fuel pump running when it shouldn't, injectors open when they shouldn't, make me suspect that the ECU is hosed or at least seriously unhappy. The ECU controlls both of these functions, and I can't think of any failure mode where it would make sense for the ECU to deliberately do both these things.
The fuel pump is controlled entirely by the ECU. The fuel pressure regulator has nothing to do with controlling the pump i is just a variable restrictor, don't bother replacing that it is a waste of time. The fuel pump is powered via the fuel pump relay (one of two metal-cased Bosch relays on flying leads close to the ECU). The relay coil is fed on one side by the switched ignition circuit, and earthed on teh other via the ECU when the ECU wants the pump to run. The normal behaviour is that the ECU switches the pump on when you switch the ignition on, and then switches it off again if it doesn't receive an engine running signal. It starts the pump again if it gets the engine running signal (when you crank the engine over, for example). The engine running signal is taken from the low tension ignition circuit, on mine (V8S) this comes from the ignition amplifier but on others it seems to come from the coil; in principle it could come from anywhere in the low tension circuit. The signal is normally carried by a single wire that runs along the near side rocker cover and into the passenger footwell. There should be a diode in series with the wire on the engine side of the bulkhead. There are various faults that could prevent the ECU from running the pump when it should, but other than a stuck relay or a hosed ECU I can't think of any fault that would make it run continuously.
The injector problem is another funny. The injectors are bank fired, meaning that all four injectors on one side of the engine fire together, then the other four fire. For one (or more) injector to stay open without all of that bank staying open suggests it is probably a mechanical fault in the injectors. Have they been allowed to dry out and/or got damp and corroded?
Either you've got a whole lot of unrelated problems, or something serious amiss with the ECU. If this problem started immediately after work on the immobliser, I wonder if either the immobiliser is wired up wrong, or the ECU has been spiked when they reconnected the battery.
The fuel pump is controlled entirely by the ECU. The fuel pressure regulator has nothing to do with controlling the pump i is just a variable restrictor, don't bother replacing that it is a waste of time. The fuel pump is powered via the fuel pump relay (one of two metal-cased Bosch relays on flying leads close to the ECU). The relay coil is fed on one side by the switched ignition circuit, and earthed on teh other via the ECU when the ECU wants the pump to run. The normal behaviour is that the ECU switches the pump on when you switch the ignition on, and then switches it off again if it doesn't receive an engine running signal. It starts the pump again if it gets the engine running signal (when you crank the engine over, for example). The engine running signal is taken from the low tension ignition circuit, on mine (V8S) this comes from the ignition amplifier but on others it seems to come from the coil; in principle it could come from anywhere in the low tension circuit. The signal is normally carried by a single wire that runs along the near side rocker cover and into the passenger footwell. There should be a diode in series with the wire on the engine side of the bulkhead. There are various faults that could prevent the ECU from running the pump when it should, but other than a stuck relay or a hosed ECU I can't think of any fault that would make it run continuously.
The injector problem is another funny. The injectors are bank fired, meaning that all four injectors on one side of the engine fire together, then the other four fire. For one (or more) injector to stay open without all of that bank staying open suggests it is probably a mechanical fault in the injectors. Have they been allowed to dry out and/or got damp and corroded?
Either you've got a whole lot of unrelated problems, or something serious amiss with the ECU. If this problem started immediately after work on the immobliser, I wonder if either the immobiliser is wired up wrong, or the ECU has been spiked when they reconnected the battery.
mickypee said:
1.The fuel pump carries on running when the ignition is on, and appears not to come up to pressure. I suspect the regulator is to blame, so I will replace it tomorrow.
It seems the fuel pump has been wired directly to the ignition then, with the ECU control removed. The initial pump prime on turning the key is timed by the ECU and not done to run the fuel rail up to pressure (AFAIK fuel pressure is not monitored).
mickypee said:
2.Initially there was a lack of sparks, but Johno came to the rescue with a new ignition amp module.
If this somehow got fried maybe the ECU did too. Any welding been done?
mickypee said:
3.most worryingly number one and two injectors are firing constantly when the ignition is on, even though the engine isn't running! Why?
Alternative to my theory re (1) this almost suggests the ECU thinks it is receiving a constant 'engine running' signal. Very odd given that it should be a pulsed signal, and even odder if only two injectors are firing. Can't explain - unless the injectors are not actually opening/closing but are in fact stuck open all the time?
mickypee said:
Mr Disappointed
If this lot occured after the alarm was installed I think you need to get the car back pronto.
Thank you for all the replys to my posting.
I don't think I was specific enough in some of the details. Take 2!!
Firstly, let me explain. The car has been built from the ground up with no detail left unturned. The engine has been rebuilt and as such, hasn't run yet. The car is now virually finished and just the last few details are being completed. It is together enough for the engine to run, today even more so as now the dash, cd player, etc are all in and wired up. Almost all the electrics work, only a headlight and a couple of duff conections still to sort.
I tried to run the engine even before the new alarm was fitted and still had no joy.
The engine turns over fine, and I now have sparks at the plugs after a new ignition module was fitted. It appears that the main relay works, but the second fuel pump relay doesn't. This I think is a faulty component as if you swap the two relays around, it still doesn't work. Two new ones coming tomorrow. In the mean time I have manually closed the fuel pump relay to try and make the engine run. It was then I noticed that the pump continued to run, I expected it to come up to pressure and then slow or stop. It didn't! Hence suspecting the pressure regulator.
So although I have ignition and fuel, I can't explain the injectors firing as they are. If you turn on the ignition and de-immobilse the circuits, but don't turn the engine over injectors 1 & 3 possibly 5 are heard clicking. This has puzzled me as I assumed that a pulse from the coil would be needed to make this happen. I'm sure it is something really simply, but alas I can't find a solution to the problem. Everything else seems in order, and now it's mostly complete suprisingly few other gremlins. It's to be expected I suppose if the car has been taken apart to the extent it has. Any help or suggestions most welcomed.
I don't think I was specific enough in some of the details. Take 2!!
Firstly, let me explain. The car has been built from the ground up with no detail left unturned. The engine has been rebuilt and as such, hasn't run yet. The car is now virually finished and just the last few details are being completed. It is together enough for the engine to run, today even more so as now the dash, cd player, etc are all in and wired up. Almost all the electrics work, only a headlight and a couple of duff conections still to sort.
I tried to run the engine even before the new alarm was fitted and still had no joy.
The engine turns over fine, and I now have sparks at the plugs after a new ignition module was fitted. It appears that the main relay works, but the second fuel pump relay doesn't. This I think is a faulty component as if you swap the two relays around, it still doesn't work. Two new ones coming tomorrow. In the mean time I have manually closed the fuel pump relay to try and make the engine run. It was then I noticed that the pump continued to run, I expected it to come up to pressure and then slow or stop. It didn't! Hence suspecting the pressure regulator.
So although I have ignition and fuel, I can't explain the injectors firing as they are. If you turn on the ignition and de-immobilse the circuits, but don't turn the engine over injectors 1 & 3 possibly 5 are heard clicking. This has puzzled me as I assumed that a pulse from the coil would be needed to make this happen. I'm sure it is something really simply, but alas I can't find a solution to the problem. Everything else seems in order, and now it's mostly complete suprisingly few other gremlins. It's to be expected I suppose if the car has been taken apart to the extent it has. Any help or suggestions most welcomed.
That's rather alarming (no pun intended), if the engine has been rebuilt with a new cam the last thing you want is to spend ages cranking it over, the first few minutes of a cam's life are critical and it needs to be held at moderate revs for 10-15 minutes to give the cam a chance to run in.
On to the symptoms. Injectors opening when the engine is stationary seems very strange. Do you have any evidence that they are triggering other than the noise? You could confirm that the noise you hear comes from the injectors by disconnecting them. You could confirm which injectors are triggering by connecting a NOID diagnostic light (or perhaps just an analogue volt meter) in place of the injector. The injectors shouldn't fire unless the ECU gets an engine running signal from the ignition, and all four injectors on one side of the engine are wired together (a single wire in to the ECU) so this is doubly strange, and hopefully you are mistaken about what the injectors are doing.
On to the symptoms. Injectors opening when the engine is stationary seems very strange. Do you have any evidence that they are triggering other than the noise? You could confirm that the noise you hear comes from the injectors by disconnecting them. You could confirm which injectors are triggering by connecting a NOID diagnostic light (or perhaps just an analogue volt meter) in place of the injector. The injectors shouldn't fire unless the ECU gets an engine running signal from the ignition, and all four injectors on one side of the engine are wired together (a single wire in to the ECU) so this is doubly strange, and hopefully you are mistaken about what the injectors are doing.
Mmmm, The plot thickens! Have just plugged in the two new fuel control relays, and nothing. I am starting to suspect that the ECU is to blame. I have checked every thing else, and I can find nothing wrong.
Would any one have a spare ECU for a 95 500 they could lend or sell to me? I is strange as I drove the car into the workshop, and all was well. The ECU has lived in the warm ever since, and now it would seem to be at fault.
Any ideas gratefully received.
Would any one have a spare ECU for a 95 500 they could lend or sell to me? I is strange as I drove the car into the workshop, and all was well. The ECU has lived in the warm ever since, and now it would seem to be at fault.
Any ideas gratefully received.
Well after changing the ECU(thanks Dave) and messing with the ignition timing, it rummbled into life for the first time in two years. And what a lovely noise it makes too.
Remarkably there are no leaks or drips from anywhere. The only fault seems to be the temp gauge which shows cold. Fans cut in and out so I expect it's the sender. Oil pressure is a healthy 45 at idle up to 60ish at higher rpm. Cam and followers are quiet, so all in all I'm very pleased.
Just finishing the interior bits, man who fitted the carpets forgot about the seat belts, so having to modify that area. Done one side, passenger side to finish.
Centre console is back in along with a Leven gear lever surround. Have to say what a class act they have done there. Really makes the inside look finished. This is complemented with the indicator stalks, handbrake etc. It looks a picture now that the dash and heater panel are back in all finished in walnut. (London Carridge Co)
Just the suspension bushes and geometry and it's something like nearly ready.
Thanks for all the advice with the engine problem.
Mr Happy
Remarkably there are no leaks or drips from anywhere. The only fault seems to be the temp gauge which shows cold. Fans cut in and out so I expect it's the sender. Oil pressure is a healthy 45 at idle up to 60ish at higher rpm. Cam and followers are quiet, so all in all I'm very pleased.
Just finishing the interior bits, man who fitted the carpets forgot about the seat belts, so having to modify that area. Done one side, passenger side to finish.
Centre console is back in along with a Leven gear lever surround. Have to say what a class act they have done there. Really makes the inside look finished. This is complemented with the indicator stalks, handbrake etc. It looks a picture now that the dash and heater panel are back in all finished in walnut. (London Carridge Co)
Just the suspension bushes and geometry and it's something like nearly ready.
Thanks for all the advice with the engine problem.
Mr Happy
I cant stop driving it now, trouble is its 2500 rpm for me. Had planned a quick, slow blast "sur le continent". Given the forcast,not. It will be six months at my average mileage before i can give it some welly.Thinking about putting it on blocks and leave it running.
>> Edited by david beer on Wednesday 27th July 21:45
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