Have i got the wrong distributor? Does it matter??

Hi guys,

I have a 3.9 EFI, Its been bugging me since i got it that there is no vacume advance on the distrubutor so i thought i'd look into it today......

I have the err4252 - Distributor 3 pin 42562

Is this ok?

From what i've found so far i think they used it on a 3.5. That all i know. The description suggests it should have 3 wires goin to it, but obviously there are only 2 wires from my harness.....

It does seem to advance when i rev it, but thats just sat on the driveway, not under load.

I know the engine was fitted with a Holley Carb at some point, maybe they changed it then???

CONFUSED!!! Can anyone shed some light...?

If it is a standard 3.9 with OEi gnition set up it should have a vacum advance on the dizzy.

Checking the parts list it is a dizzy for a 3.5 not a 3.9. I guess someome has been messing about.

Yh, I wonder what the difference is......

AFAIK both the 3.5 and 3.9 had DLM8 distributors and both had vac advance. I believe the difference is in the ignition amplifier - 2 pin or 3 pin. There is a conversion lead available but don't ask me what the part number is. The other variation is whether or not the amplifier is attached to the dizzy body or if it is remote but the dizzy itself and the pickup are the same. There were some variations in advance curve depending on the engine but I'm not sure the differences are particularly significant.

HTH.

Here it is:

STC1212 Link lead

To go back to your original Q as far as I know you need the vacum advance as without it the engine won't work very well under load. I am sure someone more experinced than me will correct me if I am wrong. Cheers Nick

Yeah I think you're right. It seems the unit I have advances timing based on engine speed probably using bobweights. It's probably off a 3.5 carb engine.....

So I need to replace it.

3 options doing to mind

1. The correct o/e replacement
2. A real good Malory replacement
3. Or for practically the same money the Megajolt system making it super accurate and waterproof....

Any thoughts V8 heads......

No experience of megajolt but am aware not a simple plug and play. Even if you get a basic Ignition map it may will need tweeking for your engine. Mallory really nice but again needs setting up correctly. I bought a NOS lucas dizzy and had it set up with more advance by Steve Gunning. Works well on petrol and LPG. If you have the skills megajolt is the most modern system,then Mallory and finally OE Lucas. IMO Lucas works fine for me. Bitter experience has taught me NEVER NEVER buy cheap pattern ignition parts, they will let you down and cause heartache.

Thanks for the advice country. I've been mulling it over all day. I really like the idea of the megasquirt for fuel and spark because in theory it will give me correct ignition timing, get rid of my faulty AFM and show me easily what my engine is doing. However, after what you've said, I'm really starting to worry that I'll never get it set right..... After all, the hours of r&d put into the OE system must be worth something...... The thing is, I dint want my landy to be a toy which I have to constantly re program. I want it to work..... If u know what I mean.... Oh decisions..... I hate them!!!!

Ok, Megajolt requires hours of tuning or cash paying an"expert" to do it for you, Mallory is a nicely made bit of kit and once set up by said "expert" will be more efficient, MPG, power!!! than OE kit. I have OE dizzy modified, 8mm Taylor leads, low impedence coil, total cost £350. Truck runs on LPG get equivilent of 25 to 30 mpg and goes well, also novice like me can care for it. Suspect Mallory would be better than OE converted dizzy but have no experience. Another point Lucas CUX14 injection an adapt to various perameters. If you convert to Megasquirt every time you change anything you might have to reset fuel/ignition map. I suspect that if you can do the work yourself the best way forward is Megajolt ignition conversion, to get rid of the dizzy, and keep the Lucas CUX14 for simplicity. I am a relative novice so the more experienced may have other views. As far as heads go speak to Vougese39 he is the skilled man for that job.

I ment to ask, who's that steve guy that did ur's?

apart from the problem that 14cux is horrendously uneconomical, because it fores injectors in banks of four at a time.

megasquirt would pay for itself very quickly if you use the car a lot and buy at the right time.

eventually i want to upgrade

But at the right time? where should I be looking?

Steve Gunning Ex army IMO very skilled man, 01225 350711. Give him a ring he can give you sound advise and do any work you need. I would agree that Megajolt is better than any dizzy, just depends on how much you can do yourself. Well worth it if you have the skills and experience, better mpg, power, and reliabilty. If you run LPG you can run 2 fuel maps 1 for petrol 1 for LPG. I,m not skilled enough so have to stick to dizzy as to pay someone could end up best part of £1000 to supply fit Megajolt. Cheers Nick

Fitting it is no problem for me, the map on the other hand..... I better get reading

Post a piccy of dizzy and amp!

Is it brown and purple leads - if so needs vaccie

Megajolt setup is about £400 but really good,

new dizzy and amp will be about £250 (ok, but suggest not going OEM for amp)

Mallory about £200 (good, but can be a lot of hassle)

when i say buy at the right time, i mean:

if you have a broken dizzy and need to spend 250 on a new one, you could spend 500 on megasquirt and it would pay for itself quickly, only an extra 300 quid probably.

Countrymansussex said:

Another point Lucas CUX14 injection an adapt to various perameters.

Click to expand...

Really?? How does it do that without any volatile memory? The 14 CUX does not "learn" it works on fixed fuel maps and as such it is not an "adaptive" system.

14CUX doesn't adapt, it just wastes fuel all the time!