Broken Ignition Again......

[griff430]

I took my Griffith 4.3 out for a blast at the weekend to enjoy the winter sunshine, and all was going well - it was running as sweet as a nut. Stopped for around 10 minutes for a photo opportunity and the carried on the journey, only to experience very rough running, and the car appeared to be running on about half the cylinders. Stopped once again for about half an hour. When I got in to go again, it started fine, but as as soon as I tried to pull away, it stalled, and has not started since

I've had some ongoing electrical problems since I stored the car for 6 months last winter, and I thought they had been over come, but the problem keeps coming back to bite me in the ass! I have replaced the following:

Dizzy Cap
Rotor Arm
Ignition Module
Plug Leads
Fuel Pump Relay
Engine Run Relay

I figure this only leaves the coil and the distributor itself (and possibly the ECU). Is there anything else I could check? Also, does anyone know roughly how much a new distributor, or where I could find a used one?

Any advice would be MUCH appreciated, because these electrical problems have been going on for about a year, and I can't enjoy the car's full potential, because I'm always waiting for the next breakdown to occur.

Thanks in advance,

Dan.

[GreenV8S]

It is not sensible to try to guess the fault from those symptoms, you will end up replacing everything (from the sound of it you are well on the way already). You need to track the fault down. I would start by working out whether it is a fuel or ignition problem. Check the state of the plugs. Generally wet means you have fuel, dry means you don't. (Duh!) At least then you know which system you are trying to troubleshoot.

[pebbledash]

My 500 did this, managed to solve it by, cleaning all the plugs on the loom that are between the ECU and the engine bay. I found that the injectors were not always fireing due to cruddy connectors.

I would suggest taking to a dealer as they have kit that shows this up in a second flat... and saves hours off guessing etc.

however once diagnosed. the fault still has to be traced

[griffter]

pebbledash said:

My 500 did this, managed to solve it by, cleaning all the plugs on the loom that are between the ECU and the engine bay. I found that the injectors were not always fireing due to cruddy connectors.

Ditto - but a 4.3. injector connectors, ecu connector, low tension connectors to/from dizzy and coil - anything and everything which is anything to do with the ignition/injection basically. Also all sensor connectors (throttle pot, stepper, temperature, air flow etc) Use a tiny bladed screw driver to get in the female connectors, and very low grade sand paper (gently) on the males. Brake cleaner or propoer contact cleaner to clean up. I copper greased where apprpriate (careful you don't short anything) and sealed with ignition sealer so hopefully the hard work lasts. It's worth it - knowing it's done reduces the potential for further problems.

pebbledash said:

I would suggest taking to a dealer as they have kit that shows this up in a second flat... and saves hours off guessing etc. however once diagnosed. the fault still has to be traced

Not sure the precats have quite the same diagnostic capability? May be wrong.

[griff430]

Thanks for the tips. There is definitely something preventing a spark, because there's no HT from the coil. Also, when it was running roughly on about half the cylinders, there was a strong smell of unburtnt fuel.

I've taken it to a TVR specialist a couple of times, who so far hasn't been able to trace the problem, because it's intermitent. I'm not convinced that the 4.3 has a very sophisticated diagnostics package, so again, it's a bit of trial and error

[GreenV8S]

Sounds like you have a straight forward ignition fault then. Any decent auto electrician should be able to diagnose this very quickly.

[pebbledash]

griffter said:

Not sure the precats have quite the same diagnostic capability? May be wrong.

my problem did not show up on the ECU fault diags, ecu thought everything was, just jim dandy..

what they plugged in was a clip onto each injector back, that lit each time the injectors fired, and a clip on the HT leads to show them firing. The best issue was when it did not start, the motor cranked over quite happily but the injectors never fired.. hence in would not start.

moving the ECU sometimes made it run lumpy or not run at all, hence the wiring suspission.

The car always ran well with the ECU on the floor in the passangers footwell. even when to the extent of borrowing an ECU, which after an inital good spell showed the same syptoms, initialy it had everyone baffled, until it finaly did it on cue when I took the car in to be looked at.

I beleive the diags in the ECU for the 4x and 500 is similar, except the codes for the Lambda sensors. I am sure Steve H will confirm at some point.

[griff430]

Yep, mine is just as random. I went to check it at lunchtime, and it started on the first turn of the key. There just seems to be no pattern. It was still running lumpy though, when I took it out for a spin.

[pebbledash]

griff430 said:

Yep, mine is just as random. I went to check it at lunchtime, and it started on the first turn of the key. There just seems to be no pattern. It was still running lumpy though, when I took it out for a spin.

Could be wiring then.. get some switch cleaner, and clean all the plugs and sockets you can find, including the ECU.

mine was random and would even come and go over bumps inthe road, or with passangers pressing their feet in the footwell.

editied to add..
The one that cured my fault is burried behind the dash, its a brown plug on mine with about 5 pins in (its about 2 inches in size) it takes the injector feed form the ecu before going into the engine bay..

>> Edited by pebbledash on Friday 28th January 14:34

[jamiet]

GreenV8S said:

It is not sensible to try to guess the fault from those symptoms, you will end up replacing everything (from the sound of it you are well on the way already). You need to track the fault down.

Totally agree. And if you're not an expert or dont have the right testing tools take it to someone who does. I thought I had a good idea of what I was doing and ended up replacing virtually everything in an effort to solve a running problem. Took it to peninsula who solved it almost straight away. They started at the air intake and worked their way back looking for problems. Turned out to be colapsed liner in the induction pipe after the air meter, something I would never have thought of. Simple when you know how!

[griff430]

Yes, I tend to agree with you. The trouble is, it's even got David Batty scratching his head at the moment. Is it possible that a main dealer may have more dioagnostic tools to find the fault?

[cptsideways]

STOP........




It'll be the dodgy crap wiring to & from the coil/condensor/ballast resistor. Remove the heat shielding sorry the black tape that holds it all together you'll find a large collection of overheated exposed wires with the shielding peeling away & broken connections.

Deen had the same problem on his Chim & it was'nt until I spent the best part of an hour huddled over the engine (it was the only warm thing for miles on a freezing December night) after a pub run that went wrong that I spotted it. Deen had spent weeks & ££££££'s sorting out the electrical gremlins (not) & all it was crap insulation, lack of heat shielding & vibration causing the wiring to give up.

[deeen]

griff430 said:

Yes, I tend to agree with you. The trouble is, it's even got David Batty scratching his head at the moment. Is it possible that a main dealer may have more dioagnostic tools to find the fault?

Find someone who really knows what he is doing with a multimeter. Get him to check each step of the way where the signal is going backwards and forwards between the coil, distributor and ignition amplifier. That way you will at least know where to start looking for the broken wire / dodgy contact... it's very hard to spot when the insulation is intact and the break is inside it. A new dizzy is £400, an hour with a multimeter is cheaper!

As CptS said, the Blackpool kit car wiring under the bonnet is not really up to the heat and vibration generated.

Funnily enough, D Batty couldn't find my broken wire either... CptS found it when we broke down outside the pub. I thought he was being really helpful when he jumped under the bonnet, now it turns out he was just keeping warm!