Griff 500 misfire update
Discussion
I posted some time ago about my intermittent misfire, the car will run perfectly for miles then all of a sudden it would misfire and loose power then would clear after something like 30 seconds. The second last time the engine cut out completely, I coasted to a halt and tried to restart, it would fire then immediately die....I tried about 6 times and gave up as I was on a bad corner and tried to push the car back to a safer place, I then tried to start it again....it fired right up and ran perfectly all the way home. I have since replaced the Ignition amp, coil and fuel filter. I had driven over 160 miles without issue until It happened again yesterday morning. I had only driven about 4 miles (on a fully warmed up engine) then about 1/2 a mile from home it started misfiring again, I made it home ok and drove into my garage....by that time it was running perfectly again. Later I drove about 40 miles with the Rovergauge connected without issue. I stopped at my sons flat on the way back for about 20 minutes but when I started the car there was a loud bang from the fuel tank, I drove about 20 metres then I thought I should remove the fuel cap to see if there was pressure or vacuum but nothing! This morning I disconnected the Carbon canister and blanked of the plenum. I have since done 142 miles without issue with the RG connected.
Has anyone any suggestions as to what the issue is? The strange thing is I have been able to do 160 miles so maybe intermittent is not the correct term !!
Has anyone any suggestions as to what the issue is? The strange thing is I have been able to do 160 miles so maybe intermittent is not the correct term !!
After you blanked off the carbon canister connection on the plenum did you leave the end of the pipe free to air? I ask this because many years ago my Opel Manta suffered misfiring problems and the cause was eventually tracked to a blocked fuel tank breather pipe. Closer inspection showed that because of the vacuum created within the tank it had partially collapsed...could this be the bang that you heard? Mantas were eventually recalled and the vent pipe led away to a dust free area.
Yes I did blank off the end of the hose as well, maybe I should put in a connector and extend the hose down to a safer area as a temporary measure? I’m sort of clutching at straws, maybe the 2 issues are not connected but.....I have noticed that when I turn the ignition on there seems to be a lot of air being returned to the tank as the pump primes (on a hot engine) I assume that this is normal as the fuel is vaporising due to the heat from the engine? if say the vent was blocked and the pump had been pulling a vacuum, the pressure would cause the tank to pop out again?? But in saying that one would think that with the car sitting the pressure would equalise and not keep a vacuum..
The randomness also puzzles me as I said earlier I did 160 odd miles without issue and the other day it was about 4!! Yesterday 142 !! Perhaps it’s something as simple as the suction pre filter getting blocked by something floating in the tank?
The randomness also puzzles me as I said earlier I did 160 odd miles without issue and the other day it was about 4!! Yesterday 142 !! Perhaps it’s something as simple as the suction pre filter getting blocked by something floating in the tank?
Hedgehopper said:
I have mis-lead you there, sorry. To vent the fuel tank you also need to remove the hose that goes into the carbon cannister from the fuel tank. That way the tank will vent whether or not the purge valve is open within the can.
I disconnected both hoses from the purge valve.Perhaps the fuel tank noise is a red herring.
The Fuel pump supply passes through several multiway plug/sockets any one of which if intermittent could cause mis-firing.
I had a similar problem few years back so cleaned all plug/sockets and have never had the problem since.
The plug/socket behind the passenger B post is particularly prone to damp and thus poor contacts.
This may help:
http://www.bertram-hill.com/fuel-pump-schematic.ht...
And worth cleaning the connectors to the fuel pump itself they are a bit flimsy!
The Fuel pump supply passes through several multiway plug/sockets any one of which if intermittent could cause mis-firing.
I had a similar problem few years back so cleaned all plug/sockets and have never had the problem since.
The plug/socket behind the passenger B post is particularly prone to damp and thus poor contacts.
This may help:
http://www.bertram-hill.com/fuel-pump-schematic.ht...
And worth cleaning the connectors to the fuel pump itself they are a bit flimsy!
Loubaruch said:
Perhaps the fuel tank noise is a red herring.
The Fuel pump supply passes through several multiway plug/sockets any one of which if intermittent could cause mis-firing.
I had a similar problem few years back so cleaned all plug/sockets and have never had the problem since.
The plug/socket behind the passenger B post is particularly prone to damp and thus poor contacts.
This may help:
http://www.bertram-hill.com/fuel-pump-schematic.ht...
And worth cleaning the connectors to the fuel pump itself they are a bit flimsy!
The Fuel pump supply passes through several multiway plug/sockets any one of which if intermittent could cause mis-firing.
I had a similar problem few years back so cleaned all plug/sockets and have never had the problem since.
The plug/socket behind the passenger B post is particularly prone to damp and thus poor contacts.
This may help:
http://www.bertram-hill.com/fuel-pump-schematic.ht...
And worth cleaning the connectors to the fuel pump itself they are a bit flimsy!
I have already checked the B post multi plug which was packed with either silicon grease or Vaseline, and I’ve cleaned the fuel pump terminals. I think it would be worth checking the other connectors......I’m also thinking that I could fit a fuel pressure gauge with a hose onto the fuel rail and attach it to a wiper blade so I can see if it is a fuel pump issue.....that’s my dilemma I don’t know if it’s a fuel or electrical problem.
Intermittent faults are always a pig to identify.
Other possible electrical causes are the large ECU connector and the relay bases. With possible damp in the passenger footwell and the components hanging free it is a recipe for disaster. I mounted both the relays and the ECU on the bulkhead and so far they have been fine.
Maybe get Rover-Guage and hook it up while driving, then if the fault occurs you can get some real facts rather than having to guess each time it falters.
A bit of a hassle but may save you a lot of heartache and time.
Best of luck.
Other possible electrical causes are the large ECU connector and the relay bases. With possible damp in the passenger footwell and the components hanging free it is a recipe for disaster. I mounted both the relays and the ECU on the bulkhead and so far they have been fine.
Maybe get Rover-Guage and hook it up while driving, then if the fault occurs you can get some real facts rather than having to guess each time it falters.
A bit of a hassle but may save you a lot of heartache and time.
Best of luck.
Intermittent faults are always a pig to identify.
Other possible electrical causes are the large ECU connector and the relay bases. With possible damp in the passenger footwell and the components hanging free it is a recipe for disaster. I mounted both the relays and the ECU on the bulkhead and so far they have been fine.
Maybe get Rover-Guage and hook it up while driving, then if the fault occurs you can get some real facts rather than having to guess each time it falters.
A bit of a hassle but may save you a lot of heartache and time.
Best of luck.
Other possible electrical causes are the large ECU connector and the relay bases. With possible damp in the passenger footwell and the components hanging free it is a recipe for disaster. I mounted both the relays and the ECU on the bulkhead and so far they have been fine.
Maybe get Rover-Guage and hook it up while driving, then if the fault occurs you can get some real facts rather than having to guess each time it falters.
A bit of a hassle but may save you a lot of heartache and time.
Best of luck.
Loubaruch said:
Intermittent faults are always a pig to identify.
Other possible electrical causes are the large ECU connector and the relay bases. With possible damp in the passenger footwell and the components hanging free it is a recipe for disaster. I mounted both the relays and the ECU on the bulkhead and so far they have been fine.
Maybe get Rover-Guage and hook it up while driving, then if the fault occurs you can get some real facts rather than having to guess each time it falters.
A bit of a hassle but may save you a lot of heartache and time.
Best of luck.
Yes a real PITA , I’ve never had an issue with dampness in the car at all. I will have a look at the ECU.....how TVR thought that having that rats nest of wires was acceptable is beyond me, definitely a case of out of sight out of mind !!Other possible electrical causes are the large ECU connector and the relay bases. With possible damp in the passenger footwell and the components hanging free it is a recipe for disaster. I mounted both the relays and the ECU on the bulkhead and so far they have been fine.
Maybe get Rover-Guage and hook it up while driving, then if the fault occurs you can get some real facts rather than having to guess each time it falters.
A bit of a hassle but may save you a lot of heartache and time.
Best of luck.
I’ve had my RG connected for the last 140 miles or so but the car has behaved itself.
Thanks for the suggestions they’re most welcome.
Ive just taken the car out with the Rovergauge connected, after warming up the engine I drove the car up my drive (about 20 metres) the car cut out as I was waiting at the junction, it started right away, The car drove normally for about 1/2 a mile until I pulled into a stopping place to look at the RG I took a screen shot and the short term lambda was showing 100% although running normal, I had the fuel pump set to run continuously to see if was the pump was an issue.....whilst idling the car hunted up and down a couple of times and died (pump still running) I then restarted the engine no problem and drove home.
Any ideas anyone? 😀
Any ideas anyone? 😀
das2000m said:
Ive just taken the car out with the Rovergauge connected, after warming up the engine I drove the car up my drive (about 20 metres) the car cut out as I was waiting at the junction, it started right away, The car drove normally for about 1/2 a mile until I pulled into a stopping place to look at the RG I took a screen shot and the short term lambda was showing 100% although running normal, I had the fuel pump set to run continuously to see if was the pump was an issue.....whilst idling the car hunted up and down a couple of times and died (pump still running) I then restarted the engine no problem and drove home.
Any ideas anyone? ??
Just a thought does the short term trim reset when the ECU is disconnected?.....as I had mine unplugged to check the terminals.Any ideas anyone? ??
After hooking up a fuel pressure gauge and tapait to the windscreen wiper I took the car for 15 mile round trip, at say 60 mph the gauge was reading 30 psi dropping to 28 whilst changing gear flooring it in 5th going up a steep hill it read about 36 psi. On 3 occasions whilst at idle (which was a little high 1100 rpm ish) the car cut out but immediately restarted on checking the gauge there was no drop in pressure so I think I can safely say that it is an electrical/ignition fault as opposed to being a fuel issue.
Unfortunately my lap top battery went flat just after I left the house, when I plugged it in the Rg was still reading 100% on the short term Lambda (Im not sure what this means)?
I should maybe add that the ignition stays on when the car cuts out.
Unfortunately my lap top battery went flat just after I left the house, when I plugged it in the Rg was still reading 100% on the short term Lambda (Im not sure what this means)?
I should maybe add that the ignition stays on when the car cuts out.
Have you checked the earths on the injectors? Each bank splices into one so could you be getting one bank drop and it stalls. Mine kept stalling when I put my foot on the clutch at islands but would restart but really dangerous. Mine was the engine earth cable at the back of the engine (I think) in the end but you've already checked this so must be something else.
I’ve just been out to check to see if there were any fault codes on the Rovergauge......and yes both Lambdas are showing fault codes which I have now reset.
I was checking connections in the wiring loom this morning and I’ve just discovered that I’d inadvertently put a non diode type relay into the F/pump relay plug....would this have caused todays episode of stalling? I have now replaced it with the correct type so I guess I will try again tomorrow.
I was checking connections in the wiring loom this morning and I’ve just discovered that I’d inadvertently put a non diode type relay into the F/pump relay plug....would this have caused todays episode of stalling? I have now replaced it with the correct type so I guess I will try again tomorrow.
Could be the cause. When I bought my griff years ago a normal relay was used for the fuel relay. This did cut of power to the lambdas as soon as the engine was running. The management enriched the mixture to maximum causing the engine to cut off at idle.
Solved by replacing it with the originaliteit brown relay.
Ronald
Solved by replacing it with the originaliteit brown relay.
Ronald
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