Rough Running

Author
Discussion

greymrj

2,956 posts

140 months

Wednesday 15th August
quotequote all
glenrobbo said:
Hello OP?
Hello Pete?

HELLO?

Testing testing 1 2 3 4.
Can anyone hear me? ears



Obviously not! frown

getmecoat
squeeeeele skreeeeech whiiiiine yowwwwwl Bit of feedback any help Glen?

ukflyboy

Original Poster:

235 posts

52 months

Wednesday 15th August
quotequote all
Sorry Glen, not getting your humour on this occasion, can you clarify your post??

Edit - apologies, see you've given the details of those with the Star in your quoted text.

Edited by ukflyboy on Wednesday 15th August 15:27

RayTVR

794 posts

79 months

Wednesday 15th August
quotequote all
Pete, send me a PM and I'll happily arrange to get the one I have sent to you.

Can't promise it will help, but certainly worth a try at this stage, I would have thought

GreenV8S

26,321 posts

220 months

Wednesday 15th August
quotequote all
You've obviously done a lot of investigation and I haven't followed up all the previous suggestions. Have you been able to rule out any of these areas? If so, how; if not, what have you tried so far in each area?

  • a mechanical problem (pistons, valve train, blocked exhaust etc)
  • a fuel system problem
  • an ignition problem

ukflyboy

Original Poster:

235 posts

52 months

Sunday 9th September
quotequote all
Hi all, a quick update having received the STAR tester from Philpot...

The random high idle with the ISCV plugged in seems to have made a resurgence today, so we weren't able to complete all the tests however:

- with the key on-engine off test, we got a code 11 - no fault found. I head various solenoids clicking etc which I don't think I had heard on other testers, so had a bit more confidence that it was doing the business. Interestingly it doesn't return a fault code (46) with the ISCV unplugged, so suspect this is only checked as part of the dynamic engine running tests. Unplugging the TPS correctly generated a code 35, so gave a degree of confidence in the system.

- For the key on engine running test with ISCV unplugged, we correctly got a 46, (ISCV failure). Plugging it in with the engine maintaining around 2000 rpm (symptomatic of the long-standing idle issue) we got a code 16 ("Vane air meter number 2"), for which it says to "check base idle speed". The engine then cuts out as the ECU seemingly tries to conduct more dynamic engine tests. Thinking positively, the STAR tester is at least identifying that things ain't right, we now just need to work out why!

Despite recently changing the intake plenum gasket, our thinking is that it might indicate that an excessive amount of air is still being sucked in from somewhere. A number of you have said that ignition shouldn't be sustainable with the ISCV unplugged, and for the majority of time it is, so the next plan is to work out why that is. I'm gonna try get my hands on a smoke tester to flush out where any leaks might be.

As far as these go:
a mechanical problem (pistons, valve train, blocked exhaust etc) - nope, these are a bit out of my ability to check, so I haven't done them. We'll look at them post air leak checks
a fuel system problem - difficult to confirm 100% that there isn't an issue, but having replaced filters, injectors, fuel pressure regulator and confirmed the fuel pressure looks to be in limits, I'm hoping it is sorted.
an ignition problem - we have replaced pretty much everything in the ignition system and it gives a very good spark, so not likely to be ignition.
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ukflyboy

Original Poster:

235 posts

52 months

Wednesday 3rd October
quotequote all
Well the search continues...

I acquired a smoke machine (one of the cheap Autool ones of eBay which actually seem to work pretty well!) and disappointingly it didn't reveal the panacea air leak that we were hoping. We plugged the machine into air sources (brake servo hose, intake, plenum hose) and there weren't any great leaks on engine side of the throttle body. There is definitely a small leak out of the throttle body spindle, so Lee has cleaned up the spare which seals better. There was also air leaking in around the intake hoses so currently trying to source some new ones, as never been a fan of the sprung-steel reinforced type ones.

It is at least reassuring that Lee's work in replacing the plenum and fuel rail gaskets has got it all sealed up tightly, but we were hoping that we saw massive Indian smoke signals pointing to where the problem might lie! We'll get the throttle body and the hoses sealed up properly and then re-run the smoke test and STAR tests and put the thinking cap back on!

TJC46

1,860 posts

142 months

Wednesday 3rd October
quotequote all
ukflyboy said:
Well the search continues...

I acquired a smoke machine (one of the cheap Autool ones of eBay which actually seem to work pretty well!) and disappointingly it didn't reveal the panacea air leak that we were hoping. We plugged the machine into air sources (brake servo hose, intake, plenum hose) and there weren't any great leaks on engine side of the throttle body. There is definitely a small leak out of the throttle body spindle, so Lee has cleaned up the spare which seals better. There was also air leaking in around the intake hoses so currently trying to source some new ones, as never been a fan of the sprung-steel reinforced type ones.

It is at least reassuring that Lee's work in replacing the plenum and fuel rail gaskets has got it all sealed up tightly, but we were hoping that we saw massive Indian smoke signals pointing to where the problem might lie! We'll get the throttle body and the hoses sealed up properly and then re-run the smoke test and STAR tests and put the thinking cap back on!
I have only just read all of this thread and OP i admire your determination.

You obviously have an intermittent fault, and for my twopenny worth it sounds as though it sometimes is overfuelling.

You say you have checked the temp sensor, for what its worth i would buy a new one.

Theres not much you havnt done or replaced, but some kind of overfueling problem is my guess....................it is only a guess

though, but having read all of this thread quite a few times, it seems a good possibility.

ukflyboy

Original Poster:

235 posts

52 months

Thursday 4th October
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Thanks Tom, unfortunately I don't have much choice but to be persistent with it; I can't find any professional that sounds like they might know how to solve it so the only other option is to sell it as a going concern which I don't want to do given the work that has been done on it - I'm determined to believe that I'll have years of great running with it once I can get this sorted!

There is a definitely possibility of overfuelling but it won't be due to the temp sensor - I've tested the one that was in there and a new one with an ohm metre across a variety of temperatures and they were operating correctly (checked back at the ECU also).

It's a real head-scratcher!

DamianS3

1,714 posts

118 months

Thursday 4th October
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Nightmare frown i was goint to sugges AFMs but it looks like you have already tried that.

My idle issue and manner of small oddities went away when i swapped mine for new bosch £££ !!

Good luck i know how annoying thes faults can be.

Damian S3

Barkychoc

7,843 posts

140 months

Friday 5th October
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I know they are no where near but they are very knowledgeable around old school fords - the amount of time this has been going on it could be worth a trip.
They were a non franchised ford dealer for quite some time in the 90's.
Steve who runs the workshop fixed a local TVR S not so long back that wouldn't idle - it was a break in the wiring to the idle control valve.
It didn't take them long to find it.

https://www.wilfordlaneautos.co.uk/

Chris

Maffe

461 posts

195 months

Saturday 27th October
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Have you checked the ball valve ( is it called that?) on the rockercover and the valve sitting next to it and turned the right way (same hose loop)?
Do the non cat 2.9 the butterfly valves in the air intake? If it have they can get sticky.
Maybe already checked the idle engine vale?
Cleaned and checked that the filter in the oil filling cap + hose working as it should (crankcase breather?)

Edited by Maffe on Saturday 27th October 18:14


Edited by Maffe on Saturday 27th October 18:19

lewdon

248 posts

101 months

Sunday 28th October
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It sounds as though you have tried pretty much everything. Intermittent wiring faults are obviously a b**g*r to find as broken conductors or poor connections can still make contact even during wiggle tests, only to go open circuit 5 minutes later..
Two small suggestions I didn’t notice specifically mentioned in your thread, but which you may well have tried already,
1) Try cleaning up all the pins in the small round multi-pin connector in the V of the engine which connects the sensors to the ECU (on my car it is hidden under the coil) it lives in a pretty harsh environment and is very subject to corrosion, which might distort the signals to the ECU.
2) try actually driving the car with the TPS unplugged. It will not run well but if it loses the rough running in limp home mode maybe the fault could be in the wiring to the TPS rather than in the TPS itself (I see you have already tried a new one of those).
Congratulations on your perseverance, good luck