drovers Posted September 21, 2009 Share Posted September 21, 2009 Over the last months my G reg Classic...which I've owned for 8 yrs and love (well used to...) Has developed a nasty habit of the engine completely cutting out, for anywhere between 5 sec to anything upto 10 minutes when warm or hot. Sometimes she just "mumbles" if thats a word! i.e will drop to around 1000rpm, it you press the throttle down then she cuts out , on release it will "mumble" back to say 1000 revs... Sometimes she recovers and carries on perfectly...other times she really gets the Ar$e with me, and follows up a mumbling session by cutting out as mentioned before..B!tch !!! When the engine runs it's perfect, poweful, no adverse engine noise, no smoke, an absolute gem. So I've been chasing an ignition and/or fuel fault. These are the parts I've changed and in order! New Ignition Coil New Spark plug leads ...just for the hell of it, could of been the coil to distriutor breaking down etc. New Distributor cap and rotor arm New fuel filter. by rear off side wheel New fuel relays under the Drivers seat New advance and "retard" as the old had gone senile! Had the distributor out, and all looked fine. Springs etc all connected and ok. New distributor amplifer module Check that the Airflow meter was not earthed, ie throught the air filter housing which has rubber mounts fixing it to the inner wing. When she cuts out I've tried disconnecting the Airflow meter then the Throttle potentiometer just for the hell of it, then the electrical connector to the Stepper motor at the back of the Plenum chamber. All makes no effect to her wanting to start!!! When she feels like it, she'll re-start and pretend that nothing ever happened....(now that reminds me of someone!) Iv'e just finished having a blitz on testing Earths! all seem to be OK. Getting feed up.... I do not have or know of a way to test the Fuel pump pressure accuratley or the Fuel pressure bypass switch. I tried running with no filler cap, just incase of an breather problem and vacum in the tank. I'm just about to remove the rear floor panel or cut a hole in it to get to the fuel pump. (Don't want to drop the tank out) Other suggestions have been Alternator/ ECU / Shorts in loom Or a just devine intervention that God and Land Rover don't like me anymore.. Any advise would be greatly welcomed...(And no, I don't want to Scrap it!!) Drovers Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted September 21, 2009 Share Posted September 21, 2009 Fuel pump relay, main relay (make sure you get the right type, they are not always normal pinouts) Aside from that, the usual answer: V8 Hotwire diagnostic guide in the technical archive, work through it and report back any strange findings. Quote Link to comment Share on other sites More sharing options...
vougese39 Posted September 21, 2009 Share Posted September 21, 2009 is it 3.5 or a 3.9? Quote Link to comment Share on other sites More sharing options...
steve_d Posted September 21, 2009 Share Posted September 21, 2009 Fuel pump gets my vote. Not easy to test as the ecu controls when it is on and your fault is intermittent. I would run a wire to the fuel pump (or connect at the relay) and put a cigar lighter plug on the end. Next time the fault happens plug it in and listen under the back to see if the pump is running. In the 8 years I've had a RRC it has gotten through 2 fuel pumps. Steve Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted September 21, 2009 Share Posted September 21, 2009 ^^^ Wot he says Or PRV Nige Quote Link to comment Share on other sites More sharing options...
Bille Posted September 22, 2009 Share Posted September 22, 2009 Any advise would be greatly welcomed...(And no, I don't want to Scrap it!!) Drovers I've just been through a similar thing (Hope I've solved it)with my '93 classic, It frustrated the hell out of me, seemed only to happen when vehicle got to full temperature, engine idle would slow and die at stop lights/signs or if the idle dropped to below about 700rpm, it wouldn't start until it cooled for about 10>15 minutes (Needle half way between normal operating temperature and cold, then it would start. I found that I could keep moving with the revs at 1200rpm or so which was pretty hopeless and my wife wouldn't drive it. I checked every damn thing but hesitated to replace anything (Through parts at it) until I could get a better handle on why. I had heaps of suggestions from mates and the forums of what to do with it (Wife gave me a couple:-)) eventually traced it (I hope) to where the engine earth strap was attached under the coil bracket on the inside of the fender, I removed the coil cleaned everything up, put it all back and it seems fine now, over 2 weeks and still ok. I hope this helps but it seems you have tried almost everything. Quote Link to comment Share on other sites More sharing options...
steve_d Posted September 22, 2009 Share Posted September 22, 2009 Seems to also perfectly fit symptom 4 on the Carelect list of ECU faults. Have used these guys myself and was impressed by both the price and speed of turnaround. I got my ECU back almost by return post. They will test and repair but also upgrade at no additional cost. The upgrade is almost the equivalent of 'chipping' although this ECU does not have a chip as such. I believe they change some resistor values etc. Steve Quote Link to comment Share on other sites More sharing options...
RangeyRover Posted September 23, 2009 Share Posted September 23, 2009 I would also consider looking very closely at the lead from the coil to the ecu. Clean the contact and make sure its good. If the ecu does not know the revs it will not fuel properly. Quote Link to comment Share on other sites More sharing options...
SteveRK Posted September 23, 2009 Share Posted September 23, 2009 Try disconnecting the throttle potentiometer when the engine is running normally to see if this replicates the problem. It might be a wiring problem between the pot' and the ECU, or a problem with the pot' itself Quote Link to comment Share on other sites More sharing options...
landmannnn Posted September 23, 2009 Share Posted September 23, 2009 I do not have or know of a way to test the Fuel pump pressure accuratley or the Fuel pressure bypass switch. A fuel pressure guage for efi is a useful addition to the tool box. I think mine was about £20. Quote Link to comment Share on other sites More sharing options...
drovers Posted September 24, 2009 Author Share Posted September 24, 2009 A fuel pressure guage for efi is a useful addition to the tool box. I think mine was about £20. Quote Link to comment Share on other sites More sharing options...
drovers Posted September 24, 2009 Author Share Posted September 24, 2009 Thanks for all this advise. Its been really helpful. Gone through the wiring loom with a multi meter and really given it some hassle by pulling pushing and bending the loom , especially where the loom bends or goes throught the body work and is clamped..ie fatique points, all this was done with the engine has been running. but she didn't miss a beat (Had most the dash off and the carpets up etc.) Last night took out the rear floor and........ The top of the fuel pump looked likes its got really hot at some point. as the connectors look burnt. (But I've always hear the fuel pump running when she stops.) I'm going with a new pump as advised in the posts. Plus have found that 2 of the 3 vent tubes to the expansion tank where bloked. so have cleared these. Will post results this intermittent prob has really been annoying to say the least. But huge thanks for all your comments. Will come back ASAP Mike Quote Link to comment Share on other sites More sharing options...
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