2.5 Petrol Misfiring - help!

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Jackattheback

Member
Posts
17
Location
Shropshire
Hi there. My first post.

I have a 2.5 petrol 90. 1986 vintage.

I've had it about 12 months, whilst it is never going to be an object of desire it was a very good price and is a very sound unmolested truck.

All has been well for most of that time. Runs well and starts first turn of the key and does about 20 mpg.

There have been a couple of occasions where it would suddenly and quite violently misfire. These were normally either when it had been stood for a few moments (such as filling with fuel) when it would still start straight away but miss as you accelerated away, or if you had been going on a steady throttle for a while and then accelerated. I'd put it down to some form of fuel vaporisation and was going to reroute the fuel lines further away from the engine.

However, in last few weeks problem has got much worse. It will stutter even when cold, sometime when running along at a steady speed. But it does not happen all the time. the other day I did a 3 way trip, 1st leg coughed and spluttered most of way (10 miles), same for 2nd leg, then on last leg again 10 miles ran without a hiccup.

Certain it is a fuel issue rather than ignition, as dizzy, points, coil, plugs and leads were all new when I got it and are correctly set up.

Had a look on the posts here, but nothing sounds quite like what I'm experiencing.

Any ideas? thanks.
 
Is the timing set correctly? [have you personally checked it rather than taking somebody elses word for it?]
 
Thanks for the quick replies.

Yes the timing was correct when I gave it a service a few months ago but I'll check it again.

The fuel filter. I wasn't able to change that when I serviced it. It is under the drivers foot well and looks to have been waxoyled over a number of times along with picking up loads of mud so is firmly stuck. The result is the bolt is practically round so I wasn't able to get it off. I was going to ask my garage to replace it for me sometime but may book it in to get it done specifically if you think it could be the problem. Guess from the state of it it may not have been done for a while.

Carb has had a good clean so don't think that is the issue.
 
I too have a 2.5 petrol and had the same problem. Changed the condenser and that sorted it.

My 3.9 disco used to cistern nearly as much indizzy caps, arms, leads and coils as it did in lepg

:D

Have you got decent/clean/ new ignition components?

is the carb in good order and the air filter clean and no leaks on the induction side?

What have you done maintenance wise to it?
 
Hi, will have another look at ignition components at weekend.

To answer some of the questions,

Yes weber carb and Lucas points.

No obvious induction leaks, but any tips for checking, likely weak spots welcomed.

New dizzy just before I bought it 12 months ago and leads. Done about 3000 miles since.

3 months ago gave it a service new plugs oil and air filters but as mentioned before could not replace fuel filter so will get that done. Points rotor and dizzy cap all looked good then so didn't change. Fitted a new coil last week as this was only bit of ignition side not new but no difference.

Not thought of fuel pump will have a look at that. Dirk
 
Thanks everyone. New condensor and good as new. Would never have put such an intermittent problem down to part of the ignition system. Thanks again jackatheback
 
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