Help please chaps
Discussion
Ok, I suppose my time had to come and now stuff needs fixing. Some of you know how extremely numpty my level of all things mechanical are, so with that in mind....
The car: 1989 "G" 350i pretty much standard mechanically
The problem: It'll start and go, but then you know when the trouble is starting because when you accelerate there is a moments hesitation before it actually happens. moving forward is still ok at this point, but when it comes to stopping one of three things will happen: 1. It'll behave itself and will idle normally; 2. It'll cut out as soon as I come to a stop (this is happening far too often); 3. If I stop and manage to give the throttle a blip then the revs climb to between 1,500 and 1,800 which is not at all right.
So, my usual mechanic tells me I probably need to replace the Airflow/mass meter and the Idle air control valve. I have had a look at the engine and after some guidance know that the AFM is a Lucas 2AM airflow meter (which someone else at the TVRCC meet today said was a "Flapper" type) and the Idle ACV has Bosch stamped on it. I'm told these are pretty standard Rover/Land Rover/Range Rover 3.5 EFi parts. Ok fair enoughski, I have had a quick squint on the intersurf and various ppl advising me that they should be fairly easy to find via LR/RR specialists or a scrappy or even Auto factors, but I pretty much know diddly squat about this sort of malarky and would ask the great and the good of Wedgedom if they know of anywhere that is reliable and relatively cost effective where one can get said parts. Personal recommendations always hold greater sway with me.
While I'm at it I'm probably going to replace the K&N filter as this has been pretty bashed up and change the big tube thingy from the AFM to the plenum wotsit for a matching silicone jobby because the one thats on it looks about as old as the car - if you know what I mean?!?!
While I'm writing this essay (sorry chaps), would replacing these 2 parts also help stop the lumpiness when it first starts from cold? Sometimes after I pull the car from the garage it is so lumpy that it feels like the engine will shake itself off its mounts!!!
Oh, for completeness, someone else shouted "stepper motor" at me but this has been looked for a couple of times in the past and there doesn't appear to be one on this particular RV8. I don't know why (or very much about anything, it seems)
Any help would be gratefully recieved.
Paul
The car: 1989 "G" 350i pretty much standard mechanically
The problem: It'll start and go, but then you know when the trouble is starting because when you accelerate there is a moments hesitation before it actually happens. moving forward is still ok at this point, but when it comes to stopping one of three things will happen: 1. It'll behave itself and will idle normally; 2. It'll cut out as soon as I come to a stop (this is happening far too often); 3. If I stop and manage to give the throttle a blip then the revs climb to between 1,500 and 1,800 which is not at all right.
So, my usual mechanic tells me I probably need to replace the Airflow/mass meter and the Idle air control valve. I have had a look at the engine and after some guidance know that the AFM is a Lucas 2AM airflow meter (which someone else at the TVRCC meet today said was a "Flapper" type) and the Idle ACV has Bosch stamped on it. I'm told these are pretty standard Rover/Land Rover/Range Rover 3.5 EFi parts. Ok fair enoughski, I have had a quick squint on the intersurf and various ppl advising me that they should be fairly easy to find via LR/RR specialists or a scrappy or even Auto factors, but I pretty much know diddly squat about this sort of malarky and would ask the great and the good of Wedgedom if they know of anywhere that is reliable and relatively cost effective where one can get said parts. Personal recommendations always hold greater sway with me.
While I'm at it I'm probably going to replace the K&N filter as this has been pretty bashed up and change the big tube thingy from the AFM to the plenum wotsit for a matching silicone jobby because the one thats on it looks about as old as the car - if you know what I mean?!?!
While I'm writing this essay (sorry chaps), would replacing these 2 parts also help stop the lumpiness when it first starts from cold? Sometimes after I pull the car from the garage it is so lumpy that it feels like the engine will shake itself off its mounts!!!
Oh, for completeness, someone else shouted "stepper motor" at me but this has been looked for a couple of times in the past and there doesn't appear to be one on this particular RV8. I don't know why (or very much about anything, it seems)
Any help would be gratefully recieved.
Paul
Well your mechanic is almost certainly talking through his proverbial and the car does not have an 'Idle ACV'. Nor is the airflow meter likely to be the root cause.
The ACV I think you're referring to is the Auxiliary Air Valve. It opens to admit extra air during warmup and then progressively closes with the heat from an internal element to bring the revs down from fast idle to normal idle. If you start the car and it idles at about 1200 rpm for some minutes before coming down to about 800/900, the AAV is working fine.
You don't have s 'stepper motor' either if, as you say, you have a 'flapper' airflow meter. If you did, it'd be bolted to the rear face of the plenum chamber. If, instead, you have a bulbous aluminium casting with a hose exiting it but no electrical connections, then you definitely have a 'flapper' type injection system. That casting is the over-run valve which sucks crankcase fumes in to be burned on the over-run (ie when you take your foot off).
There could be a number of faults that would cause some or all of the symptoms you have; the favourites are usually the coolant temperature sensor or a defective throttle pot. Someone will be along shortly with the usual links to the usual webpage telling you how to test all the components. If you don't know your millivolts from your kilowatt-hours then you MAY be in need of some help
Coolant temp sensor is about £12 from Landrover; throttle pot is made from purest Unobtanium but it's often just a dodgy connection thereto.
The ACV I think you're referring to is the Auxiliary Air Valve. It opens to admit extra air during warmup and then progressively closes with the heat from an internal element to bring the revs down from fast idle to normal idle. If you start the car and it idles at about 1200 rpm for some minutes before coming down to about 800/900, the AAV is working fine.
You don't have s 'stepper motor' either if, as you say, you have a 'flapper' airflow meter. If you did, it'd be bolted to the rear face of the plenum chamber. If, instead, you have a bulbous aluminium casting with a hose exiting it but no electrical connections, then you definitely have a 'flapper' type injection system. That casting is the over-run valve which sucks crankcase fumes in to be burned on the over-run (ie when you take your foot off).
There could be a number of faults that would cause some or all of the symptoms you have; the favourites are usually the coolant temperature sensor or a defective throttle pot. Someone will be along shortly with the usual links to the usual webpage telling you how to test all the components. If you don't know your millivolts from your kilowatt-hours then you MAY be in need of some help
Coolant temp sensor is about £12 from Landrover; throttle pot is made from purest Unobtanium but it's often just a dodgy connection thereto.
PR350 said:
my usual mechanic tells me I probably need to replace the Airflow/mass meter and the Idle air control valve.
(I plan to) change the big tube thingy from the AFM to the plenum wotsit for a matching silicone jobby because the one thats on it looks about as old as the car
Oh dear, first off - sack the mechanic.(I plan to) change the big tube thingy from the AFM to the plenum wotsit for a matching silicone jobby because the one thats on it looks about as old as the car
Next, the vast majority (80%) of RV8 Flapper Efi faults are caused by air leaks into the plenum chamber and dodgy connections around the Efi wiring loom.
Basically your ECU must control the fuel/air mixture within defined tolerances at all times and for all driving conditions. It can't do that if there is a rogue air leak OR if one of the components is affected by a dodgy electrical connection.
When the probabilty of both the above have been eliminated - then its down to simple component testing based upon expert knowledge or clear and concise instructions for the DIY owner.
Unfortunately, with these systems you really have to rely on self help because the so called professional experts are few and far between trying the scratch a living at £50/hour getting owners to shell out on new parts based on false diagnosis and owner ignorance, when all the while, the root cause remains unaddressed.
For air leaks and dodgy electrical connections select the PLENUM and WIRING articles from this Archive.
http://www.vintagemodelairplane.com/pages/Download...
Then study all the other Efi stuff in that index. You can learn about using multimeters from there, too.
The worst problem for the newcomer is learning the system and linking all the componenmt stuff together and for that you'll the Efi Ops Manual.
Good luck
Thanks for the replies guys.
I have spoken with a different mechanic, who I have known and trusted for years and been in touch with some ECU diagnostic chappies who are over the water from me on the Isle of Wight (who trusted mechanic has heard very good things about) and after reading this http://www.carelect.demon.co.uk/rrp1.html from their site, I think I'm going to make sure the brain is well and pop my ECU over the solent for a check up - way I figure is it can't hurt anyway and unplugging and removing it from the passenger footwell is just about within my range of mechanical capabilities haha.
Also decided I'm going to replace the elbow pipe from the AFM to the plenum and also get a new K&N filter to replace my bashed up one as I figure this also wont hurt.
I'll see what results from this and if that doesn't work, then I will investigate further. Ultimately, I might still need to replace the AFM but I figure I'll make sure Trev doesn't just have a headache!!!
I have spoken with a different mechanic, who I have known and trusted for years and been in touch with some ECU diagnostic chappies who are over the water from me on the Isle of Wight (who trusted mechanic has heard very good things about) and after reading this http://www.carelect.demon.co.uk/rrp1.html from their site, I think I'm going to make sure the brain is well and pop my ECU over the solent for a check up - way I figure is it can't hurt anyway and unplugging and removing it from the passenger footwell is just about within my range of mechanical capabilities haha.
Also decided I'm going to replace the elbow pipe from the AFM to the plenum and also get a new K&N filter to replace my bashed up one as I figure this also wont hurt.
I'll see what results from this and if that doesn't work, then I will investigate further. Ultimately, I might still need to replace the AFM but I figure I'll make sure Trev doesn't just have a headache!!!
Reading thro' the web link, I see their business is to test and repair ECUs, consequently all their diagnostics end with "Replace ECU".
Trouble is these cures dont go nearly far enough to eliminate faults before getting around to condemning the ECU. Hardly a mention of the primary causes highlighted earlier.
They also dont mention crud in the plenum, breathers, fuel flow issues and possible ignition causes (all very common theses days with older/neglected systems).
As for "ALWAYS REPLACE" the temp sensor - thats a pretty definitive opinion on something that only fails from time to time methinks? I never had an Original Equipment one go on four systems over 16 years. Maybe I'm lucky, but they probably sell those those too.
Mind you, I do appreciate that numptyism is a significant barrier but that's why I thoroughly recommend certain reading material written specifically to overcome that problem.
Trouble is these cures dont go nearly far enough to eliminate faults before getting around to condemning the ECU. Hardly a mention of the primary causes highlighted earlier.
They also dont mention crud in the plenum, breathers, fuel flow issues and possible ignition causes (all very common theses days with older/neglected systems).
As for "ALWAYS REPLACE" the temp sensor - thats a pretty definitive opinion on something that only fails from time to time methinks? I never had an Original Equipment one go on four systems over 16 years. Maybe I'm lucky, but they probably sell those those too.
Mind you, I do appreciate that numptyism is a significant barrier but that's why I thoroughly recommend certain reading material written specifically to overcome that problem.
Edited by honestjohntoo on Tuesday 13th October 11:38
Hi Paul,
your engine symptoms sound like possibly a combination of things adding up.
My motto with this stuff is to try the cheap/free things first then work up from there - at least those consistent with the symptoms.
Free Stuff
- Check/clean the earths around the engine and alternator.
- Test the throttle pot (check for smooth voltage operation as you open the throttle slowly)
- Check the throttle cable and linkage operates freely with no snags, and the cable isn't frayed.
- Check for air leaks into the plenum
Cheap Stuff
- Replace engine temp sensor but not with an Intermotor one.
Only then move onto the more expensive stuff like the AFM, ECU etc...
your engine symptoms sound like possibly a combination of things adding up.
My motto with this stuff is to try the cheap/free things first then work up from there - at least those consistent with the symptoms.
Free Stuff
- Check/clean the earths around the engine and alternator.
- Test the throttle pot (check for smooth voltage operation as you open the throttle slowly)
- Check the throttle cable and linkage operates freely with no snags, and the cable isn't frayed.
- Check for air leaks into the plenum
Cheap Stuff
- Replace engine temp sensor but not with an Intermotor one.
Only then move onto the more expensive stuff like the AFM, ECU etc...
Be interested to see the test equipment used to 'prove' these ECUs; I suspect not many places have enough kit to test them properly.
I have one here, it belongs to a guy from Burton (remember the front-ended 400SE a few weeks back). It was allegedly 'tested' by some company in the Midlands who relieved him of an eye-watering sum of money and claimed it was OK.
It wasn't. It is now, because I've repaired it. Granted, when you plugged it into the car, fired it up and went for a drive, it 'seemed' to be OK, but a prod with a 'scope showed it wasn't.
A sneaky tip that occurs to me is: if you're sending your ECU off somewhere and it still has the factory seals over the corner screws, mark them with a UV ink pen. That way if they claim to have repaired it you'll be able to tell whether they've had the covers off - it's impossible to do without breaking the seals so even if they claim to have replaced them you'll know whether they're having you on...
I have one here, it belongs to a guy from Burton (remember the front-ended 400SE a few weeks back). It was allegedly 'tested' by some company in the Midlands who relieved him of an eye-watering sum of money and claimed it was OK.
It wasn't. It is now, because I've repaired it. Granted, when you plugged it into the car, fired it up and went for a drive, it 'seemed' to be OK, but a prod with a 'scope showed it wasn't.
A sneaky tip that occurs to me is: if you're sending your ECU off somewhere and it still has the factory seals over the corner screws, mark them with a UV ink pen. That way if they claim to have repaired it you'll be able to tell whether they've had the covers off - it's impossible to do without breaking the seals so even if they claim to have replaced them you'll know whether they're having you on...
Thanks for the replies guys and I'm as cautious as the next man when it comes to my P&J.
Have spoken direct to IoW boys now and have been quoted £165 plus vat for a full overhaul of my own ECU taking 2-4 days to complete. They have also said that if I send them the AFM as well that they will reset it according to the ECU. I have relayed this to trusted mech and he thinks this is a pretty good price for everything they say they will do and, again, he said he has heard good things about them. He doesn't do electronics - give him a spanner and he is a wiz tho! They also guarantee the work for 2 years.
Anyway, for the price and the fact they are pretty local, I'm prepared to give it a go. I also called Rimmer Bros for a price of a new AFM and it's £275 plus VAT, which is kinda what I expected.
I've also spoken to Tim at ACT and discussed all this and ordered a silicone elbow and new K&N - mainly to make me feel better, hey why not!
I'll see what happens and keep all my options open - it might still need some fettling and tuning anyway so does anyone know anywhere in the south that can do this?
Other than that can anyone suggest anyone else I can chat to? I've often heard the name Mark Adams mentioned as an RV8 guru - would it be worth having a chat to him? Does anyone have his contact details?
Again, thanks for all the help guys.
Paul
Have spoken direct to IoW boys now and have been quoted £165 plus vat for a full overhaul of my own ECU taking 2-4 days to complete. They have also said that if I send them the AFM as well that they will reset it according to the ECU. I have relayed this to trusted mech and he thinks this is a pretty good price for everything they say they will do and, again, he said he has heard good things about them. He doesn't do electronics - give him a spanner and he is a wiz tho! They also guarantee the work for 2 years.
Anyway, for the price and the fact they are pretty local, I'm prepared to give it a go. I also called Rimmer Bros for a price of a new AFM and it's £275 plus VAT, which is kinda what I expected.
I've also spoken to Tim at ACT and discussed all this and ordered a silicone elbow and new K&N - mainly to make me feel better, hey why not!
I'll see what happens and keep all my options open - it might still need some fettling and tuning anyway so does anyone know anywhere in the south that can do this?
Other than that can anyone suggest anyone else I can chat to? I've often heard the name Mark Adams mentioned as an RV8 guru - would it be worth having a chat to him? Does anyone have his contact details?
Again, thanks for all the help guys.
Paul
Lets put things into context. The ECU and the AFM are both complex and decidely robust components. The AFM may suffer through uninformed internal maladjustment/poking and the ECU might fail due to dry joints or occasional component failure, yet none of the symptoms you describe would particularly draw suspicion towards either component at the start of your investigation.
So this thread is perplexing? You ask for help and advice but determinedly plough a lone furrow! Logical thinking from your fellow experienced TVRers (not me, by the way, not my bag) is brushed aside.
So what's the point? Money will surely buy you any new/tested component for the system but it can't test a dodgy throt pot connection or find an air leak unless you can find a competant technician at 50 quid/hour.
But I can see your problem as it relates to automobile technology beyond your grasp. Yet, I promise you, a few hours of concentrated reading can resolve that problem, bring familiarality and lighten a darkened tunnel.
If you cant force yourself to travel that path, be prepared for rip-off's, or at the very least, find a rolling road crew or near neighbour who do know "'ay from a bulls foot"
So this thread is perplexing? You ask for help and advice but determinedly plough a lone furrow! Logical thinking from your fellow experienced TVRers (not me, by the way, not my bag) is brushed aside.
So what's the point? Money will surely buy you any new/tested component for the system but it can't test a dodgy throt pot connection or find an air leak unless you can find a competant technician at 50 quid/hour.
But I can see your problem as it relates to automobile technology beyond your grasp. Yet, I promise you, a few hours of concentrated reading can resolve that problem, bring familiarality and lighten a darkened tunnel.
If you cant force yourself to travel that path, be prepared for rip-off's, or at the very least, find a rolling road crew or near neighbour who do know "'ay from a bulls foot"
Edited by honestjohntoo on Wednesday 14th October 22:41
dnb said:
CliveF just pointed me at this thread. We met at the car show last month - I had the other Griff.
Do you live locally? I have a spare ECU, AFM and various other parts that may help with fault diagnosis. It would at least let you eliminate the ECU if it's a wiring problem.
Hi again! Yes I am local, as in the other side of the Solent in Fareham. Would be great to have a chat. I will pm you my details.Do you live locally? I have a spare ECU, AFM and various other parts that may help with fault diagnosis. It would at least let you eliminate the ECU if it's a wiring problem.
Regards
Paul
honestjohntoo said:
Lets put things into context. The ECU and the AFM are both complex and decidely robust components. The AFM may suffer through uninformed internal maladjustment/poking and the ECU might fail due to dry joints or occasional component failure, yet none of the symptoms you describe would particularly draw suspicion towards either component at the start of your investigation.
So this thread is perplexing? You ask for help and advice but determinedly plough a lone furrow! Logical thinking from your fellow experienced TVRers (not me, by the way, not my bag) is brushed aside.
So what's the point? Money will surely buy you any new/tested component for the system but it can't test a dodgy throt pot connection or find an air leak unless you can find a competant technician at 50 quid/hour.
But I can see your problem as it relates to automobile technology beyond your grasp. Yet, I promise you, a few hours of concentrated reading can resolve that problem, bring familiarality and lighten a darkened tunnel.
If you cant force yourself to travel that path, be prepared for rip-off's, or at the very least, find a rolling road crew or near neighbour who do know "'ay from a bulls foot"
Thanks for your reply and concern.So this thread is perplexing? You ask for help and advice but determinedly plough a lone furrow! Logical thinking from your fellow experienced TVRers (not me, by the way, not my bag) is brushed aside.
So what's the point? Money will surely buy you any new/tested component for the system but it can't test a dodgy throt pot connection or find an air leak unless you can find a competant technician at 50 quid/hour.
But I can see your problem as it relates to automobile technology beyond your grasp. Yet, I promise you, a few hours of concentrated reading can resolve that problem, bring familiarality and lighten a darkened tunnel.
If you cant force yourself to travel that path, be prepared for rip-off's, or at the very least, find a rolling road crew or near neighbour who do know "'ay from a bulls foot"
Edited by honestjohntoo on Wednesday 14th October 22:41
Nothing is being discounted, nothing is being ignored, Nothing has been decided completely as yet (other than the purchase of a silicone elbow and new K&N filter), reasearch is ongoing.
I am speaking to various people I know and reading from others I have met. This is not the beginning of this problem. I have had this for about 8-10 months now and other testing and parts have already been changed. I'm sorry if I haven't replied to every single suggestion, I hope no-one has taken offence.
Just out of interest, I note the site you have linked to in this and other threads, is it your site?
I have never professed to know much of anything about the mechanics of my car. It is my shame I suppose, but others have and do and I have spoken diectly to others whose counsel I have sought in the past. I'm sorry if you feel I have given greater weight to their advice over yours.
At the end of matters, I want whats best for my wedge but ultimately the decision as to what I do to cure a problem I have felt, experienced and have, is mine.
My research and investigations will continue.
Thanks again for your input to this thread. Everything is being digested.
Paul
Personally I would go cheap and free first. Stuff you can do yourself. On top of which you will be learning very useful stuff that can be employed even if it does not immediately fix your issue. I have poured over my ECU with a magnifying glass looking for dry joints etc because it is easy and free to do (usual caveat, I have chased down dry joints on circuit boards before so was happy doing it and have a decent iron and sucker and confident in what I was doing). I did not find anything but it was ticked off the list of suspects.
I have followed fault finding guides posted on here and looked at what peole have posted and usually something clicks and bingo. Job done. I have had one or two nigglies last a while but in the end trial and error knock them on the head.
I have followed fault finding guides posted on here and looked at what peole have posted and usually something clicks and bingo. Job done. I have had one or two nigglies last a while but in the end trial and error knock them on the head.
[quote=PR350
This is not the beginning of this problem. I have had this for about 8-10 months now and other testing and parts have already been changed.
[/quote]
Before my ECU stopped working, the performance of the engine had been deteriorating over about a year. Maintenance (standard and preventive) didn`t make a difference. Borrowing an ECU to rule mine out (as in the end only idling was possible and any throttle would kill the engine), it seemed like the V8 became a V10! More like the V6 power was restored back to V8 standards of course.
Not saying that the ECU is your problem, only to inform you of similarities.
Having the ECU checked can never be bad, but a reliable source is important to not make it worse.
Rob
This is not the beginning of this problem. I have had this for about 8-10 months now and other testing and parts have already been changed.
[/quote]
Before my ECU stopped working, the performance of the engine had been deteriorating over about a year. Maintenance (standard and preventive) didn`t make a difference. Borrowing an ECU to rule mine out (as in the end only idling was possible and any throttle would kill the engine), it seemed like the V8 became a V10! More like the V6 power was restored back to V8 standards of course.
Not saying that the ECU is your problem, only to inform you of similarities.
Having the ECU checked can never be bad, but a reliable source is important to not make it worse.
Rob
Gassing Station | Wedges | Top of Page | What's New | My Stuff