occasional loss of power
Discussion
sometimes when i go to accelerate, the car starts to chugg along as if running on 6 cyls not 8. it does not happen very often but i can put my foot to the floor and it hardly accelerates. only way to stop it seems to be to keep driving for a few minutes and it coughs and splutters and then roars back to full power, or knock it into neutral and keep blipping the throttle until it revs freely again. i know it is a bit of a long shot, but has anyone else had similar promlems, or know what i can do. ('92 griff 4.3)
Weird I had this the other night and was going to post a message.
Loss of power as if something was not there, went to floor the throttle and it felt lumpy. Also when I arrived at a junction, the REV counter hunted from 500 to 1000 on the dial, it almost stalled, and would have if I had not tapped the throttle.
Guess it is look at the stepper motor time.
David
Loss of power as if something was not there, went to floor the throttle and it felt lumpy. Also when I arrived at a junction, the REV counter hunted from 500 to 1000 on the dial, it almost stalled, and would have if I had not tapped the throttle.
Guess it is look at the stepper motor time.
David
My original sparkplug HT caps and heatsheilds used to work loose and fall off. 
The main dealer reckoned he had never seen the problem before. 
I replaced all the leads and the new ones are tighter. Ever since, every time I open the bonnet I check them to ensure they are pushed on hard...never had the problem again.
The main dealer reckoned he had never seen the problem before. I replaced all the leads and the new ones are tighter. Ever since, every time I open the bonnet I check them to ensure they are pushed on hard...never had the problem again.
sounds like fuel starvation.
to have a severe loss of power i would expect coil failure or maybe the distributor amp. individual leads or plugs would make it lumpy, but you'd still have 250bhp? on a 500. starvation is more likely IMHO ofcourse.
give it a good spanking ( or wait till it faults)stop and open the fuel cap. big hiss means air tight system. new cap - or cut slot in seal / investigate breathers.is the pump on the way out?
good luck!
to have a severe loss of power i would expect coil failure or maybe the distributor amp. individual leads or plugs would make it lumpy, but you'd still have 250bhp? on a 500. starvation is more likely IMHO ofcourse.
give it a good spanking ( or wait till it faults)stop and open the fuel cap. big hiss means air tight system. new cap - or cut slot in seal / investigate breathers.is the pump on the way out?
good luck!
quote:
could be "vapour lock"...?(random comment)
It could be any one of about 50 possible reasons.
Ignition faults, injection faults etc etc etc. So I would suggest chcek the obvious and then get some diagnostics on it.
I would clean the stepper motor before doing anything. It's quick, easy and cures 99% of all known faults.
The filler cap hiss is a bit of a myth BTW . some hiss is normal. If the tank is making banging noises and hisses then that isn't and either the vent is blocked or the purge tank system is faulty.
Steve
www.tvrbooks.co.uk
quote:
Individual leads or plugs would make it lumpy, but you'd still have 250bhp? on a 500. starvation is more likely IMHO ofcourse.
give it a good spanking ( or wait till it faults)stop and open the fuel cap. big hiss means air tight system. new cap - or cut slot in seal / investigate breathers.is the pump on the way out?
good luck!
No gjm...don't give it a good spanking if the car is not running properly...this is probably the worst advice!
Check the simple inexpensive things first...
Good luck...sort it out and then go for that spanking!
>> Edited by Toffer on Thursday 12th September 17:11
most poeple seem to be scared of these cars.they are after all, range rovers with a serious body kit. (i do have a griff myself by the way and love it). you could roll it in and out of your dealers forecourt where it will then start perfectly and go for a 30 mile test drive showing no problems at all!! £50-00 please...Kerching! for spanking your car for you!
if you've been driving the car with the problem manifesting itself occasionally, the only real option you have is to stimulate the fault, or wait for the fault to appear. either way you will only be able to diagnose the fault accurately with the symptoms present. otherwise its just guesswork!
ofcouse check the obvious, ofcourse ask your dealer and other contacts. but once you have, you will then have a list of things to check / buy. you wont be able to accurately diagnose until the fault is present!
if its the coil, for example, you can replace under advice...run for a month or two...runs ok, that was the fault. or was it! you cant be sure unless you test the coil and find it faulty (IF you have the kit)
sometimes its easier AND cheaper to just get on with it. it is after all a big v8...not a vvti
i'm sure this will p*ss SOME people off, i don't mean to. but the forum is for varied opiniums so that people can get a rough idea of similar faults on similar cars. there are ofcourse exceptions to the rule, but i've already gone on a bit.once again...good luck. (waiting for the fall out!)
if you've been driving the car with the problem manifesting itself occasionally, the only real option you have is to stimulate the fault, or wait for the fault to appear. either way you will only be able to diagnose the fault accurately with the symptoms present. otherwise its just guesswork!
ofcouse check the obvious, ofcourse ask your dealer and other contacts. but once you have, you will then have a list of things to check / buy. you wont be able to accurately diagnose until the fault is present!
if its the coil, for example, you can replace under advice...run for a month or two...runs ok, that was the fault. or was it! you cant be sure unless you test the coil and find it faulty (IF you have the kit)
sometimes its easier AND cheaper to just get on with it. it is after all a big v8...not a vvti
i'm sure this will p*ss SOME people off, i don't mean to. but the forum is for varied opiniums so that people can get a rough idea of similar faults on similar cars. there are ofcourse exceptions to the rule, but i've already gone on a bit.once again...good luck. (waiting for the fall out!)
Could be the coil £50
How about a new set of leads and plugs: £75
Stepper motor: £75
My mate says its the lambda sensor: £100 each
Ignition module £65
Injectors at £40 to 75 each (x 8)
How about the air flow meter/ECU/fuel pressure regulator/thermal sensors/throttle pot?
You can very quickly spend thousands playing hunt the fault.
If it is intermittent, then they are the worst and often a Rolling road sesion is the only way. It can also be a combination of things that go wrong that then combine to give an intermittent fault.
No the V8 is not rocket science but most people don't have access to the right gear to test the components and if they do test with a multimeter, the tests are not conclusive. If there is a fault, by all means look for the obvious but often the quickest and cheapest way forward is to call in some professional help.
Steve
>> Edited by shpub on Friday 13th September 07:32
>> Edited by shpub on Friday 13th September 07:32
How about a new set of leads and plugs: £75
Stepper motor: £75
My mate says its the lambda sensor: £100 each
Ignition module £65
Injectors at £40 to 75 each (x 8)
How about the air flow meter/ECU/fuel pressure regulator/thermal sensors/throttle pot?
You can very quickly spend thousands playing hunt the fault.
If it is intermittent, then they are the worst and often a Rolling road sesion is the only way. It can also be a combination of things that go wrong that then combine to give an intermittent fault.
No the V8 is not rocket science but most people don't have access to the right gear to test the components and if they do test with a multimeter, the tests are not conclusive. If there is a fault, by all means look for the obvious but often the quickest and cheapest way forward is to call in some professional help.
Steve
>> Edited by shpub on Friday 13th September 07:32
>> Edited by shpub on Friday 13th September 07:32
I am starting to wonder if my cars odd behaviour the other day is due to this post:
www.pistonheads.com/gassing/topic.asp?t=17317&f=9&h=0
liquid on the ECU connectors.
Last night it drove perfectly, very odd.
David
www.pistonheads.com/gassing/topic.asp?t=17317&f=9&h=0
liquid on the ECU connectors.
Last night it drove perfectly, very odd.
David
Last year my ECU connectors had corroded badly enough that there were running problems. Garage suggested a previous owner might have had it steam cleaned thus forcing moisture in - the corrosion could take a while to build up but, of course, with regular use and summer the heat started some chemical magic.
Anyway, it was just a clean up with a wire brush job, I believe - 1/2 hour labour at most!
Anyway, it was just a clean up with a wire brush job, I believe - 1/2 hour labour at most!
Before you start changing anything, it might be a good idea to have the ECU tested, or borrow/ try a different one (Mark Adams 01694 720144) he can test them on the bench.
Its probably a wiring fault.
Its a good idea to replace plugs & leads anyway unless they are newish.
It sounds like a fairly dramatic "break down" so forget Stepper motor ( this only controls a throttle closed by'pass) injectors wouldn't cause this but the electrical feed to them might.
The other possibility is unstable fuel pressure, possible causes: bad connection at pump , sticking fuel regulator ?
Your best bet is to phone Mark.
good luck ,Tim
Its probably a wiring fault.
Its a good idea to replace plugs & leads anyway unless they are newish.
It sounds like a fairly dramatic "break down" so forget Stepper motor ( this only controls a throttle closed by'pass) injectors wouldn't cause this but the electrical feed to them might.
The other possibility is unstable fuel pressure, possible causes: bad connection at pump , sticking fuel regulator ?
Your best bet is to phone Mark.
good luck ,Tim
many thanks for all your help people. i have decided that the best solution would be to get it on a rolling road. once i find the cause of the problem, i will post the outcome in this topic so if anyone else has similar problems then hopefully my answer might shed some light on it for them.
ok - i just thought i would put this up as i have had part of the solution to my problem fixed and i thought it might help others when they are searching through archives looking for similar threads. Tower View Race services found that the earth lead off one bank of the fuel injectors was loose and not making a proper connection sometimes - hence massive loss of power but car kept chugging along on the other injectors until i went over a bump and the electrical connections sorted themselves out. solving this sort of problem was way beyond my technical knowledge. i still have the problem of the car intermitantly stalling when i come to a halt - but it restarts easily enough - looks like i will have to get it on the rolling road, but at least one problem is solved.
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