Andrew H

I installed a new MSD distributor a few weeks ago. I didn't immediately check the timing, but the engine started first time every time, for a little while. Gradually the engine got more and more difficult to start (with the old distributor it always started really quick), though once started was ok. The car seemed slightly sluggish/heavy while driving normally (and marginally hesitant) but still seemed to have loads of power on hard acceleration.

I then decided to check the timing -it appeared to be about 12 degrees BTDC - I adjusted to the exact specs, 6 degrees BTDC and seemed slower but I'd say rougher too.

After that, drivablility was simlar, though possibly a bit more hesitant.

Since then, the engine smoothness has got even worse -really unpleasant to drive (day by day). It nearly stalled lots of times yesterday and has hardly any power at all (and DRINKS fuel! -feels like driving an old underpowered cadillac/tractor in one). The car is very hesitant now and has no mid range power (about the same as a 2L diesel i would say!)

I checked the timing again today, in case the distributor had slipped and it's exactly where I left it. Idle sounds rough to me and takes a long time to steady to idle as well (feels like it's idling at about 400rpm in the end)

I opened up the dist cap and the rotor doesn't seem to have any play in it (left or right movement) with no dampness in the cap.

I'm wondering if the gear has got damaged at the bottom of distributor, but lack of play (in the rotor) and timing that appears to be ok made me think otherwise (and the distributor slotted in really easily in the first place). The instructions said to use natural engine oil (I didn't do that as I have v expensive new synthetic oil in there as seems a bit silly draining it all out to put natural oil in) -though I did use the special red oily stuff that came with the distributor. I would have checked this first but it's a real pain getting all the stuff unscrewed around the dist. to get it out.

Only other thing, I've noticed a very slight burning smell, but don;t konw if I'm imagining this as I don't usually go opening up to take a look so frequently!

I'm really worried now that if the distributor gear has worn, that it might have ruined the engine too. If it is that, how do I know whether I've installed it properly next time?

I very much doubt the problem relates to anything other than distributor or timing as that's all that's changed (except new 8.5mm MSD wires, but I've checked all of them too).

(until the old distributor broke, the car was running perfect)

Thanks for any advice anyone has!!

Doctor J

OK, you didn't say what distrib you have - but if it's a magnetic pick-up type, here's an easy fix to try:

MSD (for reasons known only to themselves) sometimes mark the mag pick-up leads with reversed polarity compared to GM. Try switching the +/- reluctor wires, if you haven't already done so, inside the distrib cap.

MSD put a write-up about this and lots of other installation info on their website - you might want to take a look at it ...

HTH

Andrew H

thanks for your advice... (much appreciated!) I'll check that out (I assume there's no danger of damaging the distributor by changing the wires round).

By the way, it's the 87+ stock-style distributor with external coil that's fitted to all TPIs (I believe) -sorry, forgot to mention that! -it does have a magnetic pick-up.

Something I meant to mention before, if I've followed the directions for stopping timing advance for timing etc and got the reading, is there any way that the timing reading I'm getting is wrong, as it feels wrong!! -but I'll check-out the MSD issue first and see what happens....


I'll report back.

Andrew

Andrew H

I thought I better report back for anyone who reads this so they know what the cause was and might help somebody...

In the case of the 8366 MSD distributor for 87-93 GM cars (as it's made for GMs ignition system specifically, I don't think it's ever necessary to swap terminals inside the distributor but I'm waiting for a response back from MSD to confirm this -as it's mentioned as an issue in their techinical section on their site).

However, in my case (as was pointed-out by the doc above in an email) it turned out to be my error in reading the timing. Well, I actually blame the chilton manual (seriously! haha -I really don't totally blame myself)

In the manual, it suggests to link up terminals A+B on the computer module connector under the dash (using a paper clip or similar). It said something along the lines that if this stops timing advance, then this is doing it's job and that there's then no need to disconnect the brown black wire that is a single wire protruding from the wiring loom above the AC/ heater unit in TLHside of engine bay.

The paper clip does (in my case) stop timing advance so I thought this was fine.

HOWEVER!! -when today I tried to check timing with the cable disconnected (above AC unit in engine bay) I found that my timing was soooooo far retarded (DEGREES AFTER CENTRE) that it was wayyy off the scale, it was about 15-20 degrees too far retarded! -it's a wonder the car starts or runs at all (well it starts, but barely runs! -I guess the fact that all the ignition compenents are top spec new MSD helps.

Well my advice to anyone checking the timing, just start the engine, let it run to reach temperature (I judge this when the car idles between 450-600 rpm -depends on V8 model in drive). then stop the engine -disconnect the wire, -attach the timing inductive pickup as close as possible (but not ridiculous so it burns or gets caught in the wiring) to the plug. Restart engine (service light will probably come on) -check and adjust timing. I need to check whether it matters whether the car is in neutral or idle in drive for this, but I don't think it matters -I'll post a question seperately about this.

hope this helps anyone who's been stuck in the same dilemma as me!!