Help - Griff intermittant losing power
Discussion
Hi,
I have a 1994 Griff 500 preserp. Need help diagnosing an intermittant fault.
went to the Thrills in Hills peak run and car developed this fault 3 times in 5 days..
Driving normally not pushing it, it seems to lose a couple of cylinders and runs really sick and eventually stalls.
if I turn off ignition and restart it, fault has cleared and I continue with no problems.
Whilst creeping along in traffic on way home it done it again and stalled, I quickly restarted whilst rolling along and fault cleared and drove 100miles without a hiccup.
Has anyone experience of this fault, difficult to diagnose when car running ok. Have cleaned connectors on MAF and distributor and reseated all plug leads before coming home so it didnt clear fault.
Searched on here but no-one posted anything similar.
Any help would be appreciated...
Alex
I have a 1994 Griff 500 preserp. Need help diagnosing an intermittant fault.
went to the Thrills in Hills peak run and car developed this fault 3 times in 5 days..
Driving normally not pushing it, it seems to lose a couple of cylinders and runs really sick and eventually stalls.
if I turn off ignition and restart it, fault has cleared and I continue with no problems.
Whilst creeping along in traffic on way home it done it again and stalled, I quickly restarted whilst rolling along and fault cleared and drove 100miles without a hiccup.
Has anyone experience of this fault, difficult to diagnose when car running ok. Have cleaned connectors on MAF and distributor and reseated all plug leads before coming home so it didnt clear fault.
Searched on here but no-one posted anything similar.
Any help would be appreciated...
Alex
It could be caused by a number of issues. Mine had similar symptoms to yours a little while back. Attached Roverguage which showed a faulty TPS. The fault on the TPS was probably a build up of crap on the potentiometer wiper arm which would clear if the throttle was wiggled about for a few cycles but problem would re occur if the contamination again stuck to the wiper arm contact.
Bottom line is to suggest wait till the issue comes back and take a look with Roverguage.
Bottom line is to suggest wait till the issue comes back and take a look with Roverguage.
Had something similar some time ago. Appeared mainly on bumpy roads but could happen on normal road as well. Loss of power, lumpy, but still idling. And immediately cured after restart. Ecumate pointed to road speed sensor. Found a loose/intermittend cable on the road speed sensor down by the diff. Fixed it, problem gone. Worth a try.
Your car may or maynot have the 100amp fuse but in any case that is not your problem. This fuse is in the charge circuit so if it failed the battery would not charge then you would eventually break down only in this case you would not be able to restart with a flat battery.
Far more likely (but by no means the only option) if the fuel pump circuit. Relays can become unreliable as can their contacts, immobiliser can give issues, fuel pump itself can fail. All of these faults can (temporarily) reset them selves with an ignition recycle.
Best of luck...intermittent faults are the bain of my life.
Steve
Far more likely (but by no means the only option) if the fuel pump circuit. Relays can become unreliable as can their contacts, immobiliser can give issues, fuel pump itself can fail. All of these faults can (temporarily) reset them selves with an ignition recycle.
Best of luck...intermittent faults are the bain of my life.
Steve
As Steve D says above very likely to be the fuel pump circuit.
In addition to the items he has mentioned there are also three plug/sockets in the circuit any one of which can give an intermittent contact. This was my problem with similar symptoms a few years back.
Worth checking and cleaning the contacts especially the plug/socket in the passenger foot-well and the ones behind the B post.
This may help:
http://www.bertram-hill.com/fuel-pump-schematic.ht...
In addition to the items he has mentioned there are also three plug/sockets in the circuit any one of which can give an intermittent contact. This was my problem with similar symptoms a few years back.
Worth checking and cleaning the contacts especially the plug/socket in the passenger foot-well and the ones behind the B post.
This may help:
http://www.bertram-hill.com/fuel-pump-schematic.ht...
Thanks for the replies, definitely giving me some more indications of what is causing the problem.
It cant be the 100amp fuse as my car isnt fitted with one. Ages ago I was working under the car and noticed the plate on the chassis where the fuse normally lives and there wasnt anything there. 2 large brown wires run from the alternator to the started solenoid without a break.
I will check the road speed sensor, change the Fuel pump relays which are original and may need replacing. As far as the Immobliser I would like to remove it but trying to work out how, is impossible, I called carl baker and he would only fit a new one at great expense.
I have ordered the Rovergauge lead with software to try and diagnose the 14cux electronics.
well worth coming on here before stripping the car down blindly...
Thanks
Alex
It cant be the 100amp fuse as my car isnt fitted with one. Ages ago I was working under the car and noticed the plate on the chassis where the fuse normally lives and there wasnt anything there. 2 large brown wires run from the alternator to the started solenoid without a break.
I will check the road speed sensor, change the Fuel pump relays which are original and may need replacing. As far as the Immobliser I would like to remove it but trying to work out how, is impossible, I called carl baker and he would only fit a new one at great expense.
I have ordered the Rovergauge lead with software to try and diagnose the 14cux electronics.
well worth coming on here before stripping the car down blindly...
Thanks
Alex
Mine did something similar years ago, would lose a bank and it would run really rough kicking neat fuel out into the exhaust and complete power loss. Was random so very dangerous. I changed the engine earth lead and checked all the injector earth wiring (I think each bank splice together into a common earth so two easy(ish) checks to do at minimal cost. Mine hasn't done it since but unsure which one made the difference.
FFG
FFG
Couple of replies.
Ref. putting loads of fuel in on one bank. Have seen this where the coil is mounted on a bracket off the plenum. The injector earth wiring for cyl.2 had rubbed through on the coil bracket so the injectors on that bank were running full time.
Ref. changing relays. Be aware they are not a normal 5 pin relay. Normal relay has pin 87 (normally open) and 87a (normally closed) these have 2 pin 87.
Steve
Ref. putting loads of fuel in on one bank. Have seen this where the coil is mounted on a bracket off the plenum. The injector earth wiring for cyl.2 had rubbed through on the coil bracket so the injectors on that bank were running full time.
Ref. changing relays. Be aware they are not a normal 5 pin relay. Normal relay has pin 87 (normally open) and 87a (normally closed) these have 2 pin 87.
Steve
bobfather said:
....and your insurance!!!
Also your car if someone has a mind to nick it.Has any owner ever had a TVR stolen or even heard of one being taken.
I ask as a while back the local TVR agent told me that to his knowledge no TVR has ever been stolen, but that was a while ago though.
I am electronics competent was a comms eng for 40 years,
I had a cobra immoboliser thatcham 2 fitted for the insurance which is additional to the Gemini alarm as thats not thatcham approved.
I want to remove the sounder under the bonnet which is very corroded from the weather. also the Gemini box under dash.
Tried tracing all the wires a few years ago but gave up as they go into the loom as one colour and re-emerge as different colour.
I thought the relays screwed onto the side of the main Gemini box was the central locking...
Alex
[quote=waggy]
……….Tried tracing all the wires a few years ago but gave up as they go into the loom as one colour and re-emerge as different colour.
I thought the relays screwed onto the side of the main Gemini box was the central locking...
Alex /quote]
My car had a Meta system and the alarm controlled an external Central locking Relay module see here:
http://www.bertram-hill.com/tvr-griffith-central-l...
The Gemini system could well be different.
……….Tried tracing all the wires a few years ago but gave up as they go into the loom as one colour and re-emerge as different colour.
I thought the relays screwed onto the side of the main Gemini box was the central locking...
Alex /quote]
My car had a Meta system and the alarm controlled an external Central locking Relay module see here:
http://www.bertram-hill.com/tvr-griffith-central-l...
The Gemini system could well be different.
Did you mean the MAF , I cleaned the hotwire a couple of years ago.. if i disconnected the MAF it wouldnt cause the fault im getting, it just would run rough,, my symptoms feel like 2 or more plugs have been disconnected, theres no acceleration and eventually engine stalls. Thanks for the info i do appreciate any ideas..
A few weeks ago my speedo dropped to zero and didnt register till i stopped and restarted car. This could have been the start of the problem, im going to check the speedo sensor wiring and then replace the fuel relays and see if that cures it,,
Alex
A few weeks ago my speedo dropped to zero and didnt register till i stopped and restarted car. This could have been the start of the problem, im going to check the speedo sensor wiring and then replace the fuel relays and see if that cures it,,
Alex
I have a 1994 Griff 500 also.
I don't have a 100amp fuse.
The road speed sensor, is in fact in the gearbox and a fault does not give the symptoms you describe, plus it's easily spotted if faulty as the speedo stops working and the car tends to stall if it tries to return to tickover from high revs. other than that it runs fine (ask me how i know)
I'd start by replacing the relays. if it doesn't fix the fault then you have a known good set as spares which is never a bad thing.
I don't have a 100amp fuse.
The road speed sensor, is in fact in the gearbox and a fault does not give the symptoms you describe, plus it's easily spotted if faulty as the speedo stops working and the car tends to stall if it tries to return to tickover from high revs. other than that it runs fine (ask me how i know)
I'd start by replacing the relays. if it doesn't fix the fault then you have a known good set as spares which is never a bad thing.
FFMan said:
I have a 1994 Griff 500 also.
The road speed sensor, is in fact in the gearbox and a fault does not give the symptoms you describe, plus it's easily spotted if faulty as the speedo stops working and the car tends to stall if it tries to return to tickover from high revs. other than that it runs fine (ask me how i know)
I have the T5 Gearbox so my road speed sensor is taken off the propshaft next to Diff, this is connected via a black box M0559 behind the dash whch tells the ECU that im moving. I know this because I had a fault 5 yrs ago when engine kept stalling at traffic lights. The black box signals the ECU when you speed drops below 7mph , The ECU raises the revs so engine doesnt stall.The road speed sensor, is in fact in the gearbox and a fault does not give the symptoms you describe, plus it's easily spotted if faulty as the speedo stops working and the car tends to stall if it tries to return to tickover from high revs. other than that it runs fine (ask me how i know)
see this prev thread on it = https://www.pistonheads.com/gassing/topic.asp?t=12...
If your road speed sensor is in the Gearbox then you must have the Rover LT77 Gearbox as fitted to the 4.0 Griff.
regards Alex
Edited by waggy on Saturday 2nd June 07:12
Eventually sorted the problem,
Found that 2 of the Plug extenders had cracks in the porcelain underneath the metal shrouds. when engine was hot they shorted the spark to the metal shroud causing a misfire.
Fitted new porcelain plug caps and leads as supplied by Tvr parts and been ok ever since.. attended the Silverstone classic and various other meets over the last 3 weeks in really hot weather and hasnt missed a beat.
might help others with similar problems..
Alex
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