Rough Running

Author
Discussion

ukflyboy

Original Poster:

235 posts

52 months

Sunday 12th March 2017
quotequote all
Sorry folks, been chaotic few months but time to get back on this and get it sorted!

So doing a search on the internet everyone seems to suggest that cleaning fuel injectors is not for the amateur, especially not if you want to know it is done properly to rule out a problem. Is it just a case of get it to a garage and let them do it?

I still want to do an on-road fuel pressure test (see separate thread) to rule out that and when it isn't raining on the weekend, I'll take it out until I have a problem and measure manifold temperatures to see if that indicates one of the cylinders isn't pulling its weight.

Someone from work said he had an identical problem (but on an entirely different engine) recommended replacing the rotor arm; anyone with 2.9i think it is worth getting a new one and replacing it?

Thanks for your continued help. I think I might be nearing the limits of my ability/patience sorting this, so if the above fails then I'll have to take it to a garage and hand them large quantities of money to sort. Anyone got any recommendations in the Bucks/Berks/Oxon area?

phillpot

14,492 posts

119 months

Sunday 12th March 2017
quotequote all
ukflyboy said:
So doing a search on the internet everyone seems to suggest that cleaning fuel injectors is not for the amateur, especially not if you want to know it is done properly to rule out a problem. Is it just a case of get it to a garage and let them do it?
If you're okay wirth taking them out send them off to Injectortune



ukflyboy said:
Someone from work said he had an identical problem (but on an entirely different engine) recommended replacing the rotor arm; anyone with 2.9i think it is worth getting a new one and replacing it?
For what they cost why not try one............. rotor arm

ukflyboy said:
I think I might be nearing the limits of my ability/patience sorting this, so if the above fails then I'll have to take it to a garage and hand them large quantities of money to sort. Anyone got any recommendations in the Bucks/Berks/Oxon area?
Sometimes it pays to "bite the bullet" and hand it over to the professionals rather than replacing stuff willy nilly that doesn't need replacing and get it sorted.......... just a matter of finding a good garage familiar with old Ford engines scratchchin

ukflyboy

Original Poster:

235 posts

52 months

Sunday 12th March 2017
quotequote all
Totally agree about your last statement. I did partially get the car to get my hands dirty, but I'm at the point I'm happy to pay a pro to take it and try and sort it so it is ready in time for spring. Unfortunately the local garages I spoke to seemed to be clueless about anything you can't plug a modern diagnostics tool into and had less of an idea than me about it (and that is saying something!).

Thanks for the link to the rotor arm; I'll try that, then fuel injectors, then a wheelbarrow of cash!


phillpot

14,492 posts

119 months

Sunday 12th March 2017
quotequote all
ukflyboy said:
Unfortunately the local garages I spoke to seemed to be clueless about anything you can't plug a modern diagnostics tool into and had less of an idea than me about it (and that is saying something!).
I think that is the problem, finding a garage that know what they're doing and won't just do a bigger version of what you're doing (no disrespect) ... keep throwing new bits at it!

Majority, but may be not all, TVR specialists seem to be all about V8's and the newer TVR engines.

TVRees

842 posts

48 months

Sunday 12th March 2017
quotequote all
I was in the garage today re-assembling my ISCV and throttle plate housing onto the air plenum and I thought about your problem.

It would not be too difficult to take off the above and give them a good clean (especially inside). Maybe you have an internal blockage somewhere, and I don't mean that personally.

When re-fitting, make sure that all gaskets are also renewed and well sealed.

Or did you do this already ?




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ukflyboy

Original Poster:

235 posts

52 months

Sunday 26th March 2017
quotequote all
Well I'm not brave enough just yet to say it's completely fixed however, having replaced the rotor arm, given the plugs another clean and poured a bunch of injector cleaner into the fuel, I took it out for an hour and a half today with no signs of the rough running. Only time will tell how long it stays that way for though! In cleaning the garage I also found 6 spare injectors that I got off Mark when he sold me the car, so I'll probably send them off to get refurbished so that if I need to change them in future I have a fully functioning set good to go.

Next projects are:
1) Fix the clutch which seems to empty itself of fluid over time and require regular bleeding. Some signs in the footwell that it may be the master, but will likely change to Landrover slave and master with flexihose at the same time if I can convince myself I'm up for the task!
2) Reinvigorate search for cause of random idle problem with ISCV fitted; first port of call is to fit a diode into the wire which runs to pin 21 of the ECU.
3) Sort out headlight surrounds which I've not fitted right and look awful.
4) General tidy up.

Lots to keep me busy there over spring autumn, but will no doubt be marred by some unscheduled maintenance at some point!

Thanks for you help everyone!

ukflyboy

Original Poster:

235 posts

52 months

Saturday 27th May 2017
quotequote all
Well I was right to be cautious about having fixed the rough running problem as it came back with gusto this afternoon. I had it out for a good run yesterday in the searing heat and after an hour today the rough running symptoms reappeared unfortunately. Starts to 'fart' under load and runs very lumpy even with the foot off that gas. Decided to pull over and get the AA out to look at it and he wasn't able to help at all, trying the usual suspects like the TPS, eng temp sensor etc without any luck. He seems to think it is an overfuelling problem (certainly smells like it!) but wasn't able to shed any light on why that would suddenly start when it got hot. It is almost like the heat is causing something to break down and tell the engine it needs a bunch of fuel. When you can get it running, it seems to run best at high revs, but is rubbish at 3000, farting and popping away.

Any ideas what might be causing overfuelling, particularly when hot? Previous multimeter investigation suggests the temp sensor is outputting fine. Alternatively, anyone know of a Cologne 2.9i genius that could sort me out with a wheelbarrow of cash?!

Barry S1

1,689 posts

125 months

Sunday 28th May 2017
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Have you cleaned the AFM I had a similar problem, gave it a good clean and been fine since

MisterTee

247 posts

45 months

Sunday 28th May 2017
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When I first got my car, it started misbehaving when it got a bit hot and bothered! Turned out to be the coil breaking down.

It ran absolutely fine when it was a cooler day, but as soon as the under-bonnet temperatures started to rise it messed about something rotten.

A new coil made it feel like a different car altogether - better starting and running and been fab ever since.

Not sure whether this helps at all?

Andy

lewdon

252 posts

101 months

Sunday 28th May 2017
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A simple one to try might be switching over the AFM connectors. I believe both AFMs are fitted with temperature sensors but only one is used to feed air temperature info to the ECU. If one has a problem switching the connectors tries the other one, Probably unlikely for both to be duff..

h271mbk

42 posts

35 months

Sunday 28th May 2017
quotequote all
I had a similar problem with my s3. It would start ok, but intimitantly, after a few miles, would run rough cough and 'fart' when I put my foot down sometimes to the point where it would not run at all.
Turned out to be the in tank filter restricting fuel flow.
I would suggest starting again from scratch using a back to basics methodical approach, look at fuel supply first. Check tank outlet flow rate, 16mm hose flow rate, pump, filter then manifold pressure. Check fuel pressure regulator (diafram in regulator may have failed) replace regulator if you have a spare. Check the integrity of the induction hoses. Look for leaks in the vacuum hoses and manifold. The injectors aren't that easy to check, but after a prriod of rough running pop out the spark plugs to see if they're some are a different colour to the others.
Once you've eliminated the fuel system, it must be electrical. Change the spark plugs (have a look at them when they're out are they all the same colour, are they the right temperature range [and seat shape for your heads] ?) dizzy cap and rotor arm. Have a look at the engine running in the dark to look for arking. Change the coil if you have a spare. Check the coil input voltage. With the engine running, wiggle all the wires and connectors in the engine bay to see if it has any affect.
If all ok, you'll need run a diagnostic check of the fuelling system electrical components.
Good luck
N

ukflyboy

Original Poster:

235 posts

52 months

Wednesday 15th August
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Hi all, wow, 2 years since I started this thread and I'm still trying to pin point what the problem is :-(

So to update, I've had Lee Boreham helping me with this and we have taken onboard many of the points above without any luck. We've tried both the logical diagnostics approach and the 'replace-almost-everything' approach without luck. So far we (or rather the good man Lee!) have:
1) Replaced most of the ignition system, including dizzy cap and rotor arm, ignition coil and leads.
2) Replaced the old injectors with a different, completely refurbished set.
3) Sorted out a few electrical gremlins in the footwell.
4) Added the diode in the wiring to the ISCV which for some reason it didn't have before.
5) Replaced all the induction gaskets to try and eliminate air leaks (currently trying to source a smoke machine to ensure that it is all zipped up tight).
6) Replaced the fuel pressure regulator and measured to ensure that the fuel pressure is correct and consistent while it has the rough running problem.
7) Replaced the fuel filter.
8) Reset the timing to 12 deg.
9) Tried new/different ISCVs, TPS etc
10) Probably a bunch of other stuff I am forgetting right now too!

While I'm sure all of the above will not be wasted effort and will serve the car well in the long term, it still hasn't cured the extreme rough running. While it started off as occasional burbling and hesitation under load, it is now pretty consistent failure to start with lots of cracking and full throttle required to get it to catch even slightly. It will then only run very rough with a LOT of throttle applied.

Lee is currently testing the AFMs on a scope (at the suggestion of Frank Massey, the writer of the diagnostics article from Car Mechanic over 20 years ago), but would be eternally grateful to anyone that can add any fresh ideas to the mix which finally gets this sorted!

RayTVR

794 posts

79 months

Wednesday 15th August
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Pete

Have you tried using the diagnostics form the ECU? You need something called a Start tester, which will test all sensor inputs etc but also run the engine dynamically. It also allows you to 'wiggle test' around the loom in the engine bay as a way of identifying poor connections etc. There are a couple of these around which could be loaned..

Other than that - I have a spare loom for the injectors and sensors etc, which could be worth a try..


glenrobbo

12,477 posts

86 months

Wednesday 15th August
quotequote all
This ^ ^ ^ ^
I suggested borrowing a Star Tester almost two years ago ( 24 Oct 2016 )

glenrobbo said:
Have you tried using the proper Ford "Star Tester" diagnostic kit?
This has proved effective on a number of occasions for peeps on here with a persistant or intermittant fault.

There are two S Clubbers who each have one available for others to borrow and use, can be sent to you by post or courier.

Try contacting Phillpot or RayTVR by PM via their profile page.

Good luck OP.

lewdon

252 posts

101 months

Wednesday 15th August
quotequote all
Did you try taking the plug out of the top AFM and plugging it into the lower one and vice versa. Takes minutes and costs nothing.

ukflyboy

Original Poster:

235 posts

52 months

Wednesday 15th August
quotequote all
Thanks guys, yip, tried swapping the connectors around on the AFMs, even tried different AFMs as I have some spares.

I haven't tried the Star tester, but I have tried several compatible fault code readers (such as the Gunson) but with no success. When I had previously asked about this, I was advised that the other fault code readers do the same as the 'official' Star tester; is that not the case such that I should specifically locate the Star tester? If so, anyone know who it is that lends it out?

mentall

240 posts

66 months

Wednesday 15th August
quotequote all
[
Hi Pete. I know how you feel!

re Star Tester: all I can find says it does nothing more than count the diagnostic pulses: just as you can with a Gunson, or indeed by counting the pulses on a test lamp or voltmeter. Although it's much more convenient. An American book, 'How to tune & Modify Ford Fuel Injection ' (MBI 1998, ISBN 0-7603-0503-X) gives a wonderful set of blow-by-blow instructions for testing, reading and interpreting fault codes, specifically on EEC-IV systems with or without a Star Tester. I can PM you scans of the pages for particular fault codes; rather not lend you the book at the moment as I'm using it, but possibly later.

But the diagnostics didn't help with my fundamental problem.

Quote 6) Replaced the fuel pressure regulator and measured to ensure that the fuel pressure is correct and consistent while it has the rough running problem.

The problem I had with my pressure gauge was that its connector had a non-return or check valve in it; it recorded peak pressure but didn't drop unless I released the pressure. So it consistently read the correct pressure while I was suffering from fuel starvation! The valve can be removed.

But the problem I was failing to diagnose was dirt (mostly rust) in the bottom of the tank, and in the little thimble filter in the tank. Took that out, and fitted a CBS low-pressure filter outside the tank, which immediately clogged up together with the pump feed pipe.

So I sent the tank for cleaning and refurbing (the other result of rusting was perforation!), put it all back together with a larger pre-pump filter - no more problem!

If any of this is likely to be useful, I'd be happy to visit at a suitable time: You're only an hour away from me and I could do with a run out.


RayTVR

794 posts

79 months

Wednesday 15th August
quotequote all
mentall said:
[

re Star Tester: all I can find says it does nothing more than count the diagnostic pulses: just as you can with a Gunson, or indeed by counting the pulses on a test lamp or voltmeter.
That's not the case.

The Star tester does a number of further diagnostics - It will read the codes from the ECU but also has a running program which takes over the ECU while the engine is running and does further checks. It also allows you to 'wiggle test' the wiring with an audible indication if any of the connections are intermittent. Happy to loan out the one I have if it helps - send me a PM.


mentall

240 posts

66 months

Wednesday 15th August
quotequote all
Sorry to disagree, Ray:






2 extracts from the book mentioned above.

The tests are carried out by the ECU itself. What the tester does is issue instructions (through STI) and read result pulses (through STO) and interpret them. The STAR interpretation may be invaluable, especially in daily repeated use, but all the facilities (including 'wiggle', KOER which plays with idle and timing settings while running, actuator test and timing test) and the output information are always available.

However, I'm sure it's much easier to do all this with a STAR!




glenrobbo

12,477 posts

86 months

Wednesday 15th August
quotequote all
ukflyboy said:
I haven't tried the Star tester, but I have tried several compatible fault code readers (such as the Gunson) but with no success. When I had previously asked about this, I was advised that the other fault code readers do the same as the 'official' Star tester; is that not the case such that I should specifically locate the Star tester? If so, anyone know who it is that lends it out?
Hello OP?
Hello Pete?

HELLO?

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



Obviously not! frown

getmecoat