Fuel Starvation (I think)
Discussion
As per last post on a previous thread, I ran out or very, very low on fuel a couple of days ago. I've only had a short time so far to sort out the resulting problem and have a couple of questions.
I've put in a couple of gallons and so far the same thing happens, fuel pump primes normally, engine fires up then even with some throttle coaxing (or even without) dies off again. I can hear the fuel pump running, I've checked and changed relay & fuse just in case but no different. I've also removed the fuel cap in case of vacuum, no different.
I'm assuming the reason is that initial priming supplies sufficient fuel to fire but then fuel is restricted in some way, so am changing the newly replaced fuel filter to rule out contamination tomorrow. Apart from some timing adjustments following my SC install the engine was not suffering any such problem before this occurrence.
Could it be that a couple of gallons isn't enough to feed the pump ? I've been reluctant to put in more in case I end up draining it again.
If anyone has any other suggestions please let me know as it's beginning to puzzle me.
I've put in a couple of gallons and so far the same thing happens, fuel pump primes normally, engine fires up then even with some throttle coaxing (or even without) dies off again. I can hear the fuel pump running, I've checked and changed relay & fuse just in case but no different. I've also removed the fuel cap in case of vacuum, no different.
I'm assuming the reason is that initial priming supplies sufficient fuel to fire but then fuel is restricted in some way, so am changing the newly replaced fuel filter to rule out contamination tomorrow. Apart from some timing adjustments following my SC install the engine was not suffering any such problem before this occurrence.
Could it be that a couple of gallons isn't enough to feed the pump ? I've been reluctant to put in more in case I end up draining it again.
If anyone has any other suggestions please let me know as it's beginning to puzzle me.
I retarded the timing according to the SC manual, however this turned out to be too much and have advanced it bit by bit to achieve smoother running. The car had been running reasonably well (although still needing a little more advance to erradicate some "holding back" under load) on a 30 minute drive immediately before the low fuel event and I haven't adjusted the timing again since then. Consequently I don't think it's timing related.
Not sure about what your reference to the timing adjustment under SC boost is though ?
Not sure about what your reference to the timing adjustment under SC boost is though ?
Well Chaps, today I've changed fuel filter - no difference. Changed back to original fuel pump in case of blockage in new one from any crap in fuel tank - no difference. Reset ECU - no difference. Can't find any loose connections etc. Still the same problem, engine fires up & runs for a few seconds but rough & erratic then dies.
I'm now lost, any extra help much appreciated.
I'm now lost, any extra help much appreciated.
Maybe you didnt actually run out of fuel Alan and maybe this was just the start of whatever this problem is.
Have you checked ignition timing, maybe its slipped?
Air leaks?
Does your SC install involve a new chip. Is this seated in the ecu ok. ECU loom connection ok. MAF meter connection ok.
Have you checked ignition timing, maybe its slipped?
Air leaks?
Does your SC install involve a new chip. Is this seated in the ecu ok. ECU loom connection ok. MAF meter connection ok.
If its 14CUX, the MAF input is ignored for a few seconds at start up, until the ECU gets a steady reading. If for any reason the MAF reading is low or missing it will run for those few seconds, before it dies. Can you keep the engine running on the throttle at all? If it will run at 2000 rpm plus that you are looking at a big air leak.
Thanks for all the suggestions chaps. Ian, I'm beginning to think you're right about the low fuel issue being coincidental. I cannot hold any steady revs no matter what I do with the throttle, it just lurches about between about 400 & 2,000 rpm even if I keep the throttle held in one position.
The SC installation did include an ECU chip change and some wiring changes for the AFM at both the ECU end and AFM end as the larger AFM pins are different to the standard and the ECU end requires a CO trimmer fitting, I've checked the security of these fittings and all seems ok, however Blitz your description of how the Lucas uses the AFM readings does seem to correspond to my problem.
I've also had the Lambdas disconnected & removed during the SC install but haven't checked if the connections around the chassis are still secure, whilst I don't think a fault with the lambdas would cause this sort of effect could this be a possibility if somethings come adrift ?
Just to recap this problem occurred suddenly after an uneventful drive of about 40 minutes & just after a quick left, right, left at a roundabout and a blast up a steady hill, on a low fuel level hence my initial assumption of fuel starvation / contamination.
I'll recheck AFM connections tomorrow evening. Thanks again Chaps & please keep suggestions coming.
P.S. Just had one from the wife - "why don't you just get rid of the bloody thing"
The SC installation did include an ECU chip change and some wiring changes for the AFM at both the ECU end and AFM end as the larger AFM pins are different to the standard and the ECU end requires a CO trimmer fitting, I've checked the security of these fittings and all seems ok, however Blitz your description of how the Lucas uses the AFM readings does seem to correspond to my problem.
I've also had the Lambdas disconnected & removed during the SC install but haven't checked if the connections around the chassis are still secure, whilst I don't think a fault with the lambdas would cause this sort of effect could this be a possibility if somethings come adrift ?
Just to recap this problem occurred suddenly after an uneventful drive of about 40 minutes & just after a quick left, right, left at a roundabout and a blast up a steady hill, on a low fuel level hence my initial assumption of fuel starvation / contamination.
I'll recheck AFM connections tomorrow evening. Thanks again Chaps & please keep suggestions coming.
P.S. Just had one from the wife - "why don't you just get rid of the bloody thing"
Edited by Richard 858 on Sunday 18th May 21:34
Edited by Richard 858 on Sunday 18th May 21:41
Richard 858 said:
This might sound a bit lame but she's an absolute diamond, not many women would put up what she's put up with (a long story) and still come out & tow me home at 10 pm.
'Twas only a joke - mine is a gem too, best thing that has ever happened to me, puts up with all things Chimaera because she knows it's something I have always wanted to do. Bless her for caring about what makes you happy/ecstatic/frustrated/amused/exhilarated/annoyed (delete Richard, this is something really simple... double check the integrity of the coolant temp sensor connection; if you changed the sensor, stick the old one back in. The ECU is very dependent on the signal from this for mixture and a duff one will cause mayhem. Also, make sure the coolant is bled up properly; not uinknown for the sensor to be sitting in an air pocket.
Thanks Gary, I haven't (yet) changed the temp sensor, however I do have a new one spare. I'll try that this evening. Thanks again.
Incidentally I'm really beginning to think I should have followed your advice from the off and gone for an after market ECU etc. etc. Feel free to use the
smilie in any reply !
Incidentally I'm really beginning to think I should have followed your advice from the off and gone for an after market ECU etc. etc. Feel free to use the
smilie in any reply ! Gassing Station | Chimaera | Top of Page | What's New | My Stuff