'05 Precedent Ignition Head Scratcher

[Rob_C]

Evening All,

I've been looking at an '05 Precedent that was "surging" with 2 people on board but ran a lot better with one. Checked out the fuel system which was fine, checked spark and it would cut out and come back intermitently whilst in motion.

I've disconnected the rev limiter and it made no difference so I assume somehow it's the coil/ igniter unit.

What has me wondering is if I circle the carpark on right lock, it runs fine, immediately I swap to left lock it coughs, farts and misses, back on to right lock and it runs fine. I've checked all the wiring I can get too and can see nothing loose or rubbed through nor anything that is rubbing on metalwork somewhere.

Just thought I'd run it by the brains trust before I replace the coil in case I'm missing something.

Thanks in advance,
Rob

[Rob_C]

No thoughts even?

[meimk]

I had a DS come in with somewhat similar symptoms a while back. In that case it was the black "kill" wire running from the coil going to the RPM limiter had worn against engine cooling fins and would ground out intermittently, depending on bumps & turns. Even with the RPM limiter removed that wiring still runs through to join the white/black wire that runs up the passenger side of the engine (by the dipstick tube) and eventually on to the ignition switch. In normal operation either the RPM limiter or the ignition switch can provide the ground to shut down the spark. If that black portion of the wire gets damaged where it winds through the cooling fins it can ground out and kill the spark at random. Unfortunately on a Precedent you pretty much have to pull the engine to access it, under the shroud on the drivers (flywheel) side.

[Rob_C]

Thanks for the tip,

I guess it's engine out whether it's coil or not to get the shroud off.

Cheers,
Rob

[Rob_C]

Thought I'd come back and finalise this one for people searching later. All the wiring checked out so I replaced the coil and it's fine.

Didn't have to pull the engine, just the fuel tank and exhaust. You have to remove the 2 Torx body screws, pull that forward and undo the next two screws for the front to back brace and pull that up to get the exhaust out.
I used screwdriver bits in a 1/4" socket set to get the outer cowl phillips head screws out.
Then remove the 4 bolts holding the exhaust bracket on to gain access to the 10mm bolts for the cowl.
Jacking the cart up and putting it on stands makes the whole process far easier for the lower cowl bolts/screws.
If I did it again now I think it'd be around 2 hours start to finish.