Hi all.
My 95 V8 auto 3.9 (150,000 miles) has developed a bad misfire when hot - cold its pretty good. At 200,000 it had Excellent compression and no vac leaks.
To summarise within the last 12-18 months its had:
1. New genuine LR pick up coil in the Dizzy;
2. New genuine Amplifier HEI module;
3. New Plugs;
4. New HT leads;
5. New LPG Converter (3 months ago) and vapor pipe;
6. Rotor Button;
7. Dizzy Cap;
8. New genuine Lucas coil.
I have read that the Discos tend to miss within a very short time with aftermarket rotor buttons. I just put on a new one a month or so ago, branded Lucas, but I picked it up from Repco and its not genuine LR. The cap looks good but its about 12 months and 20,000 old (aftermarket). I have not tested each lead. If it’s the module I will be surprised because it should last more than 18 months (certainly the Bosch ones in Commodores etc have a much longer life).
The misfire is much worse on LPG, but thats to be expected because of the better flame front that it needs.
The vehicle has now been put on a scope and the sparke parade is said to be good. I wonder if I have sticky valve problems or valve clearance issues - yet to do a compression test or leakage test....any ideas? It is badly sooting plugs on both LPG (lean dry vapour) and petrol.
Any ideas?
Cheers
http://www.aulro.com/afvb/images/misc/progress.gif
My 95 V8 auto 3.9 (150,000 miles) has developed a bad misfire when hot - cold its pretty good. At 200,000 it had Excellent compression and no vac leaks.
To summarise within the last 12-18 months its had:
1. New genuine LR pick up coil in the Dizzy;
2. New genuine Amplifier HEI module;
3. New Plugs;
4. New HT leads;
5. New LPG Converter (3 months ago) and vapor pipe;
6. Rotor Button;
7. Dizzy Cap;
8. New genuine Lucas coil.
I have read that the Discos tend to miss within a very short time with aftermarket rotor buttons. I just put on a new one a month or so ago, branded Lucas, but I picked it up from Repco and its not genuine LR. The cap looks good but its about 12 months and 20,000 old (aftermarket). I have not tested each lead. If it’s the module I will be surprised because it should last more than 18 months (certainly the Bosch ones in Commodores etc have a much longer life).
The misfire is much worse on LPG, but thats to be expected because of the better flame front that it needs.
The vehicle has now been put on a scope and the sparke parade is said to be good. I wonder if I have sticky valve problems or valve clearance issues - yet to do a compression test or leakage test....any ideas? It is badly sooting plugs on both LPG (lean dry vapour) and petrol.
Any ideas?
Cheers
http://www.aulro.com/afvb/images/misc/progress.gif
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