Jimboxr4x4

Not been on for a couple of years and the saph has been laid up in the garage for the last 3 years with a running problem. I have decided to get off my arse and get it sorted.

Symptoms are engine vibration and reluctance to rev. All plugs have a black carbon coating and there seems to be a weaker spark across three of the four leads.I have a diagnostic test light wired in and no error codes are coming up so think all sensors are okay. I have tested with a second set of HT leads and the same problem so I'm thinking possible distributor cap / rotor issue? Does this sound about right?

Cheers.

rog

iTrader: (2)

Good place to start, rotor arm and cap are so bloody cheap that they should be replaced as a matter of course to elimitate one thing from the system.

But first and foremost I would change your plugs and check the gap is correct, save yourself a lot of fucking about if you replace the cheap things for known good/new items.

I am a little sceptical about your opinion on the spark if I'm honest though, you can't really judge properly by eye that it's in any way effecting the running of the car just by eyesight in my opinion.

rog

iTrader: (2)

Also I forgot to add that you need to check the distributor phase sensor as well, once you take off the distributor cap and rotor arn there is a sensor that you will see opposide the shaft inside the distributor, the wires become brittle and are well known to fail, so check this too.

Jimboxr4x4

Cheers Rog, some good advice. I've ordered a cap and rotor from MSD for only Ł21 delivered so i'll get some plugs as well. I'd ruled out a problem with the phase sensor as it isn't showing any error codes but i'll check the gap.

martysmartie

iTrader: (1)

It sounds as if it's misfiring!

It could well be the plugs, the thing to do is to swap it with another and see if the problem moves, if it does then the plug is the culprit, not the rest of the system!

Remember the spark doesn't really tell you much, but if you think it looks weaker outside, then UNDER compression it's only going to make it worse.

I doubt it's the rotor or the cap, as that would effect the running all over, unless of course you have a bad contact for the respective cylinder inside the cap, again doing the above would eliminate that.

If the phase sensor was bad it would cause overfuelling!

Martin

rog

iTrader: (2)

No bother, it's bound to be something cheap and relatively simple, just finding it will take the most effort rather than changing the actual part. As for the overfuelling, true, which could also make it misfire and run like shit.

I generally tell people to check and eliminate everything they can, then you can syststematically eliminate each part of the potential problem bit by bit. Plus if you have a problem in the future it kinda helps knowing that last time you checked "X" it was ok etc...

Jimboxr4x4

Cheers for the advice chaps. If the cap and plugs doesnt cure it I'll move onto the phase sensor. Can't wait to get it back on the road - three years without a working cossie is three years wasted!

cossie moon

I had this and with lots of black smoke it was clearly over fuelling on all cylinders so checked map sensor and my pipe had come off.

Jimboxr4x4

Fitted the new rotor and cap and now running lovely, no vibration and sounds great. Looking forward to getting it back on the road for summer. Cheers for the advice.

Rax

iTrader: (1)

Chuck some new plugs in there and gap them correctly before you take it out and give it beanz.If you have only fired it up and run it or moved it a few feet it will choke it up.All of the above mentioned is something as I would/did do after being layed up.

Cap,arm,plugs,Grp A coil oil air and then start form there. All service items as a matter of course.

Phase replace and gap if necessary .Check the dizzy for play whilst you are there.There is a repair from msd.I only ever had one blow out on mine,det in 3rd on boost.New plugs gapped correctly sorted.

I must add as I am one of those people after every outing I am on inspect .Two years as a daily some 700 mile round trips though.

Jimboxr4x4

Cheers Rax, good advice. I've just ordered some new plugs. I'll check everything over and give an oil change before taking for an MOT. I'm looking to have it back on the road for May when the weather gets better.