Help - Griff intermittant losing power

[waggy]

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

[waggy]

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

[waggy]

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

[waggy]

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

[waggy]

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.

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

[waggy]

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