Back Tracking.....
Discussion
Thing is once you've managed to start it (after a long time) it is pretty much impossible to restart when warm which is why I was gonna switch to checking expected voltages/resistences to ECU.
OK, so I will plug cold start back in (it surely doesn't need any more petrol!) and check header temps. Laser temp gun ordered - building up nice collection of tool things!
OK, so I will plug cold start back in (it surely doesn't need any more petrol!) and check header temps. Laser temp gun ordered - building up nice collection of tool things!
smash said:
Thing is once you've managed to start it (after a long time) it is pretty much impossible to restart when warm which is why I was gonna switch to checking expected voltages/resistences to ECU.
OK, so I will plug cold start back in (it surely doesn't need any more petrol!) and check header temps. Laser temp gun ordered - building up nice collection of tool things!
Unlikely to be cold start injector if ambient is summer and plugs are sooty, but need to close it off as a possibility, show that on your flowchart and - most importantly - avoid giving Wedg1e the opportunity of an "I told you so" at a later date OK, so I will plug cold start back in (it surely doesn't need any more petrol!) and check header temps. Laser temp gun ordered - building up nice collection of tool things!
What do you need to keep the car running when it starts? Apprentice sat in the car with foot on accelerator?
V8 Fettler said:
... most importantly - avoid giving Wedg1e the opportunity of an "I told you so" at a later date
The number of times I've sat here going through symptoms in my head, I really just want to get at the car and fettle it myself! Shame Essex is 200 miles from anywhere I go to
- fancy a ride up north smash?
Oh hang on....
Wedg1e said:
V8 Fettler said:
... most importantly - avoid giving Wedg1e the opportunity of an "I told you so" at a later date
The number of times I've sat here going through symptoms in my head, I really just want to get at the car and fettle it myself! Shame Essex is 200 miles from anywhere I go to
- fancy a ride up north smash? Oh hang on....Anyway Wedg1e, when did your Wedge last work?
Bobby Shaftoe said:
As your mate says, a battery or alternator on it's way out will cause havoc, certainly did on mine. Best to get a multimeter hooked up as the dash volt gauge is about as accurate as stevie wonder on the firing range.
I don't know if anyone else has had this but back when i was running the stock coil and dizzy, once i had flooded a set of plugs they'd never work right again and i'd have a rough arsed idle until i put a fresh set of plugs in.
I'd set the TPS back to 0.325 volts if i were you, you'll never get full throttle enrichment with it set to 0v meaning you'll run lean at WOT.
A little trick i used was to pull the plug off the coolant temp sensor and insert a resistor in the plug to fool the ecu into thinking its up to temp. My car always ran way, way too rich at cold idle which caused stumbling, stalling etc. It's roughly a 400 ohm resistor for 80 celcius coolant temp.
The car should start and run quite well with the TPS disconnected, another variable to discount by disconnection.I don't know if anyone else has had this but back when i was running the stock coil and dizzy, once i had flooded a set of plugs they'd never work right again and i'd have a rough arsed idle until i put a fresh set of plugs in.
I'd set the TPS back to 0.325 volts if i were you, you'll never get full throttle enrichment with it set to 0v meaning you'll run lean at WOT.
A little trick i used was to pull the plug off the coolant temp sensor and insert a resistor in the plug to fool the ecu into thinking its up to temp. My car always ran way, way too rich at cold idle which caused stumbling, stalling etc. It's roughly a 400 ohm resistor for 80 celcius coolant temp.
V8 Fettler said:
Anyway Wedg1e, when did your Wedge last work?
It was working fine up to the day after its last MOT (in 2012) when the back brakes seized on (again) on a steep hill on the Yorkshire Moors. I got underneath to rip the brake calipers off (again), remembered the diff oil leak, the inboard UJs with a bit of play etc. etc. etc. and it hasn't turned a wheel since.But it will
king useless ebay traders!! Still no thermometer 
I'm no expert but assuming a 390 is more powerful than a 400 38psi looks extremely low. However based on the injector spec it's enough for the injectors to work in which case I'd expect it to start with any pressure in the fuel rail, the low pressure could cause it to run lean at higher engine loads but at start up condition any fuel should be enough and you have the cold start injector chucking more in.
I have an adjustable rising rate FPR with a gauge fitted on my 350i and i have set it to 36-38psi for idle and around 38-40psi at WOT and the engine loves it...I checked the plugs regularly and they seem to be burning okay...
Even if your fuel pressure is low it should still start and run albeit lean...Have you checked the live on the fuel pump itself?...Mine was being sporadic before it finally died..But one minute the fuel pressure was fine and then it dropped dramatically by 10psi...And then if i adjusted it back up it would jump over 10psi a day later...This was the fuel pump losing its ability to pump fuel at a regular volume.
Just something to check and tick off on the flow chart....Just seems strange that you have fuel and a spark so it should in essence fire...The timing marks on these engines can be up to 20 degrees out...Old-school techniques were used to establish a smooth idle and good power response...Any "pinking" then it was retarded a degree or so until it stopped...They didn't always use a timing gun once they had correctly found TDC....Just a thought mate...Ziga
Even if your fuel pressure is low it should still start and run albeit lean...Have you checked the live on the fuel pump itself?...Mine was being sporadic before it finally died..But one minute the fuel pressure was fine and then it dropped dramatically by 10psi...And then if i adjusted it back up it would jump over 10psi a day later...This was the fuel pump losing its ability to pump fuel at a regular volume.
Just something to check and tick off on the flow chart....Just seems strange that you have fuel and a spark so it should in essence fire...The timing marks on these engines can be up to 20 degrees out...Old-school techniques were used to establish a smooth idle and good power response...Any "pinking" then it was retarded a degree or so until it stopped...They didn't always use a timing gun once they had correctly found TDC....Just a thought mate...Ziga
Bobby Shaftoe said:
An hour +
If it's dropping to zero in a few minutes then suspect the reg or leaky injectors.
So - you have a leak somewhere. You could take off the return pipe from the FPR and put another pipe into a gallon petrol container, run it for a second and see how much petrol dribbles out after turning it off, but as there are 8 injectors then one of them leaking might be a better bet.... this would also make the engine run a bit funny especially on idle/small throttle openings.If it's dropping to zero in a few minutes then suspect the reg or leaky injectors.
Well I dunno what the fuel pressure should be - general consensus seemed to be flip the AFM flap to trigger the pump and set to 38psi which is what I did.
50psi I'm not sure would run as it was already just shy of 4% CO at idle when it was running
previously with no available adjustment left on the afm! (this was with TPS set at .3 volts - I'm sure it had been set to 0 volt previously to get the idle CO down)
Anyway - park that for time being as it can be set on rollers if it ever runs properly again, lol!
Cheers Bobby - yeah that makes mine look a bit suspect doesn't it!
I have Laser thermometer now so I will do fuel line test with resistor pack out first to confirm if leak at injectors and then get it started and report back header temps...
Thanks for all help and suggestions so far
50psi I'm not sure would run as it was already just shy of 4% CO at idle when it was running
previously with no available adjustment left on the afm! (this was with TPS set at .3 volts - I'm sure it had been set to 0 volt previously to get the idle CO down)
Anyway - park that for time being as it can be set on rollers if it ever runs properly again, lol!
Cheers Bobby - yeah that makes mine look a bit suspect doesn't it!
I have Laser thermometer now so I will do fuel line test with resistor pack out first to confirm if leak at injectors and then get it started and report back header temps...
Thanks for all help and suggestions so far
Edited by smash on Saturday 16th August 18:20
Edited by smash on Saturday 16th August 18:21
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