V8 Flapper system - stopped starting!!
Discussion
To close off a potential swerve ball, how is the automatic gearbox disable switch wired in? Only permits starting in N or P, would usually be wired into the ignition circuit.
Edit: start inhibit switch is probably a better description
Edit again: this gives some clues http://www.vintagemodelairplane.com/pages/Download...
Edit again again: if it's wired in correctly then the starter motor shouldn't turn over. So if it's wired in correctly then it cannot be the cause of the fault.
Edit: start inhibit switch is probably a better description
Edit again: this gives some clues http://www.vintagemodelairplane.com/pages/Download...
Edit again again: if it's wired in correctly then the starter motor shouldn't turn over. So if it's wired in correctly then it cannot be the cause of the fault.
Edited by V8 Fettler on Monday 18th November 18:15
Edited by V8 Fettler on Monday 18th November 18:17
Edited by V8 Fettler on Monday 18th November 18:27
So - starting but cutting out after a second? Well I was going to suggest the FPR but you've checked the fuel pressure - 30psi is in the ballpark.
The next most likely culprits are the engine temp sensor which typically causes overfuelling - does the same thing happen if you floor it while starting? Is the exhaust sooty when it fires? Does the exhaust stink of fuel?
Otherwise it could be a loose connection causing no fuelling at all. The ECU needs a trigger from the coil - if that's loose/absent then it won't be pulsing the injectors. Sounds like the "rotate the throttle with ignition on" test makes them click so that part is OK.
Check all the wire ends - connections and if you have access to an oscilloscope check whether the injectors are being pulsed while cranking/running. Good luck.
The next most likely culprits are the engine temp sensor which typically causes overfuelling - does the same thing happen if you floor it while starting? Is the exhaust sooty when it fires? Does the exhaust stink of fuel?
Otherwise it could be a loose connection causing no fuelling at all. The ECU needs a trigger from the coil - if that's loose/absent then it won't be pulsing the injectors. Sounds like the "rotate the throttle with ignition on" test makes them click so that part is OK.
Check all the wire ends - connections and if you have access to an oscilloscope check whether the injectors are being pulsed while cranking/running. Good luck.
It...ahem...seems it isn't! Just tried and it will try to start in all gears!
Had a look underneath and can't see a switch or any wires in the area...wonder if the more modern BMW that the box is from had a sensor in the lever assembly or some other high tech way of inhibiting the starter?
Had a look underneath and can't see a switch or any wires in the area...wonder if the more modern BMW that the box is from had a sensor in the lever assembly or some other high tech way of inhibiting the starter?
Adam - It will run for about one second before dying...if you plant the throttle it will rev up quickly but still die after a second.
Don't think it's sooty although it does smell of fuel, but it did a bit anyway before this problem reared it's head. Drove ok 2 weeks ago but is now playing up the first time I tried to start it again.
Won't fire at all with trigger wire disconnected and continuity test seems ok, injectors aren't clicking when snapping the throttle on and voltage is more or less absent at the power resistor on the 8 wires coming from the injectors. No oscilloscope I'm afraid, have started unwrapping the loom looking for breaks in the wiring but can't see any connectors in the circuit, would be odd for all 8 to give up at once? Worried it may be an ECU fault although checking voltage from ECU pins was ok, as was circuit continuity test and power resistor test.
Yes is an auto, starter works fine, box is from 90's (I think) BMW, can't see an inhibitor switch on gearbox, wonder if it may be in lever mechanism or operates some other way in the original car, will start and try to run in any gear!
Don't think it's sooty although it does smell of fuel, but it did a bit anyway before this problem reared it's head. Drove ok 2 weeks ago but is now playing up the first time I tried to start it again.
Won't fire at all with trigger wire disconnected and continuity test seems ok, injectors aren't clicking when snapping the throttle on and voltage is more or less absent at the power resistor on the 8 wires coming from the injectors. No oscilloscope I'm afraid, have started unwrapping the loom looking for breaks in the wiring but can't see any connectors in the circuit, would be odd for all 8 to give up at once? Worried it may be an ECU fault although checking voltage from ECU pins was ok, as was circuit continuity test and power resistor test.
Yes is an auto, starter works fine, box is from 90's (I think) BMW, can't see an inhibitor switch on gearbox, wonder if it may be in lever mechanism or operates some other way in the original car, will start and try to run in any gear!
Have you checked the voltage on the TPS centre pin? If the throttle tweak isn't clicking the injectors then the TPS is probably worn out. Then there probably isn't enough fuelling to keep the engine running.
Ignition on. Check that the TPS voltage varies smoothly from low to high as you rotate the throttle slowly. If there are sudden jumps or it cuts out you'll need a new TPS. Try it a few time too in case it's intermittent.
Ignition on. Check that the TPS voltage varies smoothly from low to high as you rotate the throttle slowly. If there are sudden jumps or it cuts out you'll need a new TPS. Try it a few time too in case it's intermittent.
Engine code is 25d*****c which I believe makes it a Range Rover lump.
Can't see an inertia switch, am I right in thinking this is normally in the AFM area of the loom?
Think this swerving, curving ball may turn out to be something out of the ordinary or down to extreme stupidity on my part! Have at least checked the earths and they are tight, will do continuity test when I've got the loom unwrapped.
Cheers!
Can't see an inertia switch, am I right in thinking this is normally in the AFM area of the loom?
Think this swerving, curving ball may turn out to be something out of the ordinary or down to extreme stupidity on my part! Have at least checked the earths and they are tight, will do continuity test when I've got the loom unwrapped.
Cheers!
Checking TPS voltage between centre (red) pin and ground gives a maximum of 3.77v and seems to increase smoothly when turned slowly as far as I can tell with a digital multimeter. Does the same when connected between red and green.
From what I've read the voltage between red and green should be around 0.325v with the throttle closed but am only reading 0.02v but then again my low quality meter seems to sit at 0.13v when not connected to anything so that's not really helping matters.
If I wasn't completely potless at the moment (pun intended) I'd try to get a replacement TPS on there to confirm or rule it out but not at all possible I'm afraid!
From what I've read the voltage between red and green should be around 0.325v with the throttle closed but am only reading 0.02v but then again my low quality meter seems to sit at 0.13v when not connected to anything so that's not really helping matters.
If I wasn't completely potless at the moment (pun intended) I'd try to get a replacement TPS on there to confirm or rule it out but not at all possible I'm afraid!
heavy squad said:
Engine code is 25d*****c which I believe makes it a Range Rover lump.
Can't see an inertia switch, am I right in thinking this is normally in the AFM area of the loom?
Think this swerving, curving ball may turn out to be something out of the ordinary or down to extreme stupidity on my part! Have at least checked the earths and they are tight, will do continuity test when I've got the loom unwrapped.
Cheers!
This http://www.rimmerbros.co.uk/content--name-Rover-V8... indicates that a 25D number is indeed RR 3.5 EFi onwards, so unlikely to have an inertia switch (but who knows what happened during the install into the Granada!)Can't see an inertia switch, am I right in thinking this is normally in the AFM area of the loom?
Think this swerving, curving ball may turn out to be something out of the ordinary or down to extreme stupidity on my part! Have at least checked the earths and they are tight, will do continuity test when I've got the loom unwrapped.
Cheers!
Do you have the 2 relays and steering module as per http://www.vintagemodelairplane.com/images/Tasters... ?
Edit: I have previously replaced the steering module (red "relay" as I recall) to clear fuel pump faults. Have you checked voltages in and out of the steering module (assuming you have one!)? Something like:
When cranking, 12v should appear at:
White/red trace at ignition switch
White red trace into steering module term 3
White green(?) trace out of steering module term 5
White green(?) trace into fuel pump relay (coil) term 85
Edited by V8 Fettler on Monday 18th November 21:38
Yep, they're up under the dash near the ECU.
Tried moving the TPS round both ways to see if that made a difference, but no. Very carefully took the lid off the ECU to check for any burnt component smell, but no. Solder on the outsides of the 2 boards looks nice and shiny.
Jobs for tomorrow night are to get the rest of the loom unwrapped and look for breaks, check voltage at injectors, check continuity between ECU and injectors, between injectors and power resistor, between TPS and ECU, check earths, check anything else I can find that is taped up in the loom, test injectors, test temperature sender.
The lack of voltage at the power resistor and lack of injector click must be a clue although the fact that it doesn't fire at all with the power resistor unplugged means the injectors must be doing something though?
At least there will be the reward of the V8 growl at the end of all this!
Quote: "The Diagnostic Challenge Continues"!!!!
Tried moving the TPS round both ways to see if that made a difference, but no. Very carefully took the lid off the ECU to check for any burnt component smell, but no. Solder on the outsides of the 2 boards looks nice and shiny.
Jobs for tomorrow night are to get the rest of the loom unwrapped and look for breaks, check voltage at injectors, check continuity between ECU and injectors, between injectors and power resistor, between TPS and ECU, check earths, check anything else I can find that is taped up in the loom, test injectors, test temperature sender.
The lack of voltage at the power resistor and lack of injector click must be a clue although the fact that it doesn't fire at all with the power resistor unplugged means the injectors must be doing something though?
At least there will be the reward of the V8 growl at the end of all this!
Quote: "The Diagnostic Challenge Continues"!!!!
I checked voltages at all the pins with the ignition on when the problem first started but that was before I found out that the pump isn't energised until the engine is cranked. Don't have a second pair of hands to help out probably until the weekend. Pump runs ok when AFM flap is opened so I think this means the steering module is ok?
Have the fuel pump relay high current terminals bridged so the pump comes on with the ignition so in theory it should run ok given no other faults?
Have the fuel pump relay high current terminals bridged so the pump comes on with the ignition so in theory it should run ok given no other faults?
Looking at the wiring diagram, that must be terminals 30/51 and 87, but that doesn't prove that the steering module is OK. You could remove the steering module and the pump would still run due to bridging links.
The bridging links have proved that the fuel pump works, you've measured the pressure in the fuel rail, that seems OK at 30psi. I suggest that you remove the bridging links and refit the fuel pump relay, then measure the voltages to the steering module and fuel pump relay when cranking (see above).
From the wiring diagram, the main relay appears to be involved in controlling the injectors. With ignition switched on, there should be 12v at white terminal 4 into the steering module, 12v at white terminal 1 out of the steering module, 12v at white terminal 85 into the main relay. It would be easier if these relays had transparent covers or telltales!
Scatter gun = change steering module, but that's £30 or more
The bridging links have proved that the fuel pump works, you've measured the pressure in the fuel rail, that seems OK at 30psi. I suggest that you remove the bridging links and refit the fuel pump relay, then measure the voltages to the steering module and fuel pump relay when cranking (see above).
From the wiring diagram, the main relay appears to be involved in controlling the injectors. With ignition switched on, there should be 12v at white terminal 4 into the steering module, 12v at white terminal 1 out of the steering module, 12v at white terminal 85 into the main relay. It would be easier if these relays had transparent covers or telltales!
Scatter gun = change steering module, but that's £30 or more
Scatter Gun haha!!
Yes terminals 30/51 & 87 are bridged. Tomorrow will try removing the bridge wire but I think it still does the cutting out after one second thing from when I tried it on saturday. Had just left it bridged as a belt and braces measure.
Seems to makes sense that with it bridged the engine should run given no other faults, unless power is being cut to terminal 30/51 once the engine fires/starter is disengaged? Which would maybe explain the symptoms and point to... dodgy ignition feed or steering module? Should be able to rig the multimeter up in the passenger footwell tomorrow and watch it when trying to start the engine without needing a second pair of hands.
Think that makes sense but then it has been quite a challenging few days so maybe not?
Nice one anyway V8 Fettler!
Yes terminals 30/51 & 87 are bridged. Tomorrow will try removing the bridge wire but I think it still does the cutting out after one second thing from when I tried it on saturday. Had just left it bridged as a belt and braces measure.
Seems to makes sense that with it bridged the engine should run given no other faults, unless power is being cut to terminal 30/51 once the engine fires/starter is disengaged? Which would maybe explain the symptoms and point to... dodgy ignition feed or steering module? Should be able to rig the multimeter up in the passenger footwell tomorrow and watch it when trying to start the engine without needing a second pair of hands.
Think that makes sense but then it has been quite a challenging few days so maybe not?
Nice one anyway V8 Fettler!
TPS measurements sound promising/good. Yes the closed position voltage is too low but it will run anyway with part throttle - that is just for setting up idle.
So if the injectors aren't clicking I would suspect the drive out of the ECU - unusual for both banks to fail at once so maybe the ECU central chip is duff - I have hear of this before on here.
I think your next step may be to borrow/beg an ECU for a quick substitution check if all the wiring checks out OK. When doing these checks test each cable from the sender end right back to the ECU multiplug.
So if the injectors aren't clicking I would suspect the drive out of the ECU - unusual for both banks to fail at once so maybe the ECU central chip is duff - I have hear of this before on here.
I think your next step may be to borrow/beg an ECU for a quick substitution check if all the wiring checks out OK. When doing these checks test each cable from the sender end right back to the ECU multiplug.
See what you mean V8 Fettler about the main relay being involved in the injector firing by joining into the power resistor wiring...main relay definitely coming on with the ignition but what I don't know is if it's going off again once the engine fires...which again would explain the symptoms. I see this wire goes back to the switch in the AFM that operates the fuel pump maybe there is a fault there that allows it to run just on ignition but breaks down once it's firing?
Or maybe as Adam says the ECU is just knackered!! Glad you think the TPS sounds non-fatal...will test injector system wires individually tomorrow.
Been racking my brains but can't think of anyone I know who'd have an ECU...bit ashamed of myself for not knowing enough people with V8's!
Or maybe as Adam says the ECU is just knackered!! Glad you think the TPS sounds non-fatal...will test injector system wires individually tomorrow.
Been racking my brains but can't think of anyone I know who'd have an ECU...bit ashamed of myself for not knowing enough people with V8's!
Ignore the throttle pot, the EFI only needs it for acceleration enrichment.
Going back to the resistor module, last I heard there was 12V going in on the brown/oranges but nothing coming out on any of the other wires.
Until you resolve this you'll get nowhere. Either there isn't, or there is and somehow you're not measuring it correctly.
You can check at any of the injector connectors: with ignition on, one wire should have about 12V and the other will probably have a few millivolts, measured from a good earth point.
The issue with disconnecting the injector plugs is that the spring fingers inside are very easily bent so that although you may measure what you expect to see, when you reconnnect it the fingers fail to make contact with the terminals in the injector so it won't fire. Not an issue here but it's as well to avoid un-necessarily pulling the plugs off more than you have to.
Squad, your profile doesn't say where you are, maybe there's someone local on the forum who could assist...?
ETA, wild stab in the dark but you haven't inadvertently swapped the injection Main relay for one of the others on the board have you? I seem to recall someone on here did that once and it resulted in the car not starting as it's a different type of relay although the terminals are arranged the same...
Going back to the resistor module, last I heard there was 12V going in on the brown/oranges but nothing coming out on any of the other wires.
Until you resolve this you'll get nowhere. Either there isn't, or there is and somehow you're not measuring it correctly.
You can check at any of the injector connectors: with ignition on, one wire should have about 12V and the other will probably have a few millivolts, measured from a good earth point.
The issue with disconnecting the injector plugs is that the spring fingers inside are very easily bent so that although you may measure what you expect to see, when you reconnnect it the fingers fail to make contact with the terminals in the injector so it won't fire. Not an issue here but it's as well to avoid un-necessarily pulling the plugs off more than you have to.
Squad, your profile doesn't say where you are, maybe there's someone local on the forum who could assist...?
ETA, wild stab in the dark but you haven't inadvertently swapped the injection Main relay for one of the others on the board have you? I seem to recall someone on here did that once and it resulted in the car not starting as it's a different type of relay although the terminals are arranged the same...
Edited by Wedg1e on Monday 18th November 23:35
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