dnesdlrow Posted January 11, 2021 Share Posted January 11, 2021 My 1986 RRC 3.5 v8 flapper has developed an engine issue. It started losing power a few weeks ago and then slowly got worse to the point it would cut out and not start again. Leave it to cool and it would start but the same would eventually happen. It did this last winter a couple of time (not as bad) but was fine all summer. it turns over fine. Engine top end was rebuilt 4 years ago with new cam, new powerspark dizzy, and May other new bits. I’ve checked fuel pump/relays and all good. I think it’s because when I turn the ignition on there is multiple electrical ticking noise around the engine bay, sounds like the whole thing is live. im guessing there must be a massive short somewhere. where do I start?! Could this be an earth/ground issue? If so does anyone have a list or diagram of where they all are? I've checked the one that goes from the back left of the block to the bonnet, it’s a wee bit frayed but ok. The battery Positive goes straight down to a chassis point. Cleary this can’t be earthed but it i on a bolt sticking out from the chassis, I’m assuming this is isolated. It’s parked up on top of a snow/ice covered hill so is a bugger to work on for any length of time. Any help/suggestions greatly appreciated. Quote Link to comment Share on other sites More sharing options...
smallfry Posted January 12, 2021 Share Posted January 12, 2021 Dont know about the ticking noise, but your original problem could be the fuel starvation. Is the pump in tank or in line, and is it a proper one and not a cheap unbranded thing ? Blockage in the tank pick up ? Feed hose internal collapse ? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 12, 2021 Share Posted January 12, 2021 Cutting out when warm is classic ignition amplifier failure, it's either on the side of your dizzy, under the coil, or lord knows if your "powerspark dizzy" does something weird or different. Ticking noise could be anything, from exhaust manifold gaskets to HT leads breaking down and arcing to the block. The positive stud on the chassis is indeed isolated but I've seen one fail and it was spectacular, as it shorted out it would cause huge misfires with flames out the back of the exhaust there's various standard binding posts that can replace them if needed. Quote Link to comment Share on other sites More sharing options...
smallfry Posted January 12, 2021 Share Posted January 12, 2021 And the coil itself could be faulty of course. Is it ticking before you actually start the engine ? The way its written suggests it does Quote Link to comment Share on other sites More sharing options...
dnesdlrow Posted January 15, 2021 Author Share Posted January 15, 2021 Thanks for the replies. The ticking noise is intermittent and happens with just the ignition on. It's not relays but a definite electrical arcing noise. It hasn't done it for a few days now, perhaps it was because the engine was wet. Now that it's dry it seems to have stopped. But it won't start now. The HT leads are relatively new (3 yrs / 2000 miles). The amplifier could be a culprit but it was new at the same time as the dizzy (4 yrs). It's mounted remotely near the coil. I've just ordered a new coil to remove that from the equation. It's high energy 0.9 ohms I think as that was recommended by Power spark. The spark seemed OK to me when I checked, but the weather was so awful it was hard to see and I was losing the will to carry on. The pump runs fine with ignition on and flap opened, and gives just over 2 bar of pressure. I'm going to try and listen for the injectors tomorrow with throttle opening. And I'll double check the spark when I get the new coil. I've got a scan from the factory workshop manual which I'm working through. It has a fault diagnosis section for a non starting engine but it says from hot. Is there another section that has the cold starting fault diagnosis? Is there a way to test the amplifier? They're about £30 so could get another. Haven't checked the fuel return to the tank. Could that prevent starting? Quote Link to comment Share on other sites More sharing options...
dnesdlrow Posted January 16, 2021 Author Share Posted January 16, 2021 A few more developments... I've been trying to work through the Workshop manual fault diagnosis but it doesn't see to match up with my Ecu plug. Initially I was a bit confused by the pin numbers but then realised it didn't matter whether it was looking from front or back those pins just don't exist on my plug! So I'm not sure whether I have a manual for a different model or if my ecu is some kind of bodge (doubtful as I had it checked about 4 years ago). I've attached a photo. I've also attached a photo from the page for the injector tests. Are the pin numbers for looking straight at the plug or from behind as I saw described elsewhere? If someone has a copy of the EFI manual for a 1986 that would be great? I also tried listening for the injectors with ignition on and opening throttle but couldn't hear anything. So what could cause this?? (my posts are taking nearly a day to be approved by the moderators, is that normal??) Quote Link to comment Share on other sites More sharing options...
teabag Posted January 22, 2021 Share Posted January 22, 2021 Firstly, find out what is stopping the engine, lack of fuel or ignition. A blocked crankcase breather can stall the engine, a similar symptom to yours, so remove the flame trap and hose to the plenum clean in petrol and refit, or better still replace the flame trap and hose if necessary. A flat battery will give the chattering relay sound “multiple electrical ticking noise” when trying to crank. Get yourself a Haynes workshop manual, I expect all u need will be in there, it helped me out in my 10 years of owning a RR3.5. Still have the manual far more info in it, than the manual for my D1. Quote Link to comment Share on other sites More sharing options...
dnesdlrow Posted January 26, 2021 Author Share Posted January 26, 2021 Thanks. I rebuilt the top end about 4 years ago and replaced many components like the flame trap and hose so I doubt it’s that but I will check. It has spark and fuel (good pressure). it now has a new coil too. The only thing that I could find amiss, which seems slightly odd but probably inconsequential, is the 6.8k resistor is missing on the speed signal between the coil and the ecu. Could that cause any issues? The battery is good and cranks the engine no problem. Quote Link to comment Share on other sites More sharing options...
teabag Posted January 27, 2021 Share Posted January 27, 2021 (edited) Something like this that i found taped to the coil on an engine bay clean up. I have two at the coil one for the efi the other is associated with a manual gearbox which i dont have. Edited January 27, 2021 by teabag Quote Link to comment Share on other sites More sharing options...
dnesdlrow Posted February 4, 2021 Author Share Posted February 4, 2021 I found the culprit! The ignition amplifier. Replaced it this afternoon and it started right up. I also sourced a 6.8k resistor online and soldered it in to the loom. I’ve got it between the ECU and the coil, it sure it’s going to make any difference other than protect the ECU? Any idea what wattage the resistor should be? I’ve seen everything from .25 to 50 watts. I couldn’t find an original resistor so had to guess. I went for 25w. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 5, 2021 Share Posted February 5, 2021 25W is massive overkill, the factory one look like it could be ~1W or maybe ~3W at a push, it's a long time since I played with Lucas EFI. Yes you do need it in there. Quote Link to comment Share on other sites More sharing options...
dnesdlrow Posted February 17, 2021 Author Share Posted February 17, 2021 Thanks. It seems to be running fine now, so I'll leave the 25w one in. Going to buy a spare ignition amplifier module too. Quote Link to comment Share on other sites More sharing options...
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