Hi all I am deleting the (single) distributor on my 1979 308 GTB and replacing it with a coil pack/ECU system as part of a wider EFI conversion. Does anyone know what is required to blank off the hole where the distributor fits, over and above a blanking plate? The splined shaft on the distributor has an ‘o’ ring on it which suggests something more is required. The plan is to make the conversion entirely bolt on/ bolt off in case I ever want to return it to original. Many thanks.
The answer depends on the vintage of your car. Earlier cars, like my July 77 build, do not have sealing plugs in the end of the intake cams, as I found out when converting to a single distributor. Later cars (not sure when they changed) have a plug fitted in the camshaft end. In either case I think you will want to remove the splined drive adaptor and seal adaptor before adding the blanking plate, which involves camshaft removal. But if you have the plugged cams, perhaps you can just leave the seal adaptor in place and put the blanking plate over that. Hopefully someone else can give you a more definitive answer on that. Edit: when you remove the distributor, you can use a long screwdriver or piece of wire to probe the end of the camshaft. With no plug, I could insert an 8" screwdriver down the cam long axis. With a plugged cam, I would think it would only be a couple of inches, or just past the splined drive adaptor.
Thank you - that’s helpful. The cam certainly seems to have a plug in it. Image Unavailable, Please Login
Good question. In my case, I have an issue with the carbs - the bases have slight warpage which is creating a base gasket leak that I just can’t fix. It results in a fast idle that gets worse as the car gets warm. I have spent a lot of time messing about with them to try and sort the problem, but still no joy, and I am wondering whether they have other issues, too. I am conscious I could look to see if I can get the carbs refurbed/restored, but tbh I am just a bit fed up with them - they have already, in theory, been refurbished at least once before. As such, I am converting to modern fuel injection with engine management, with brand new throttle bodies and hopefully no leaks! The conversion will be entirely reversible and I will retain all original parts, use all original mounting points etc for when I am mentally ready to try and get them sorted! The ignition system is part of the conversion. I am expecting/hoping/looking forward to the engine starting/running better than it could on carbs, but that isn’t the main reason for me (and is, I would admit, a bit of a slippery slope when it comes to the purpose of owning classic cars in the first place).
IIRC, I had to use an aluminum spacer, then the flat aluminum end plate to clear the cam end. The best thing about replacing the distributor(s) with a crank fired system is ignition timing consistency. No mechanical parts to stick, fatigue, or wear. My Electromotive system is programmable and allows advanced features rev limiting and like load mapping based upon vacuum, which should enable a few more mpg under cruise conditions. At 9.5 CR and 3.4 L, I'm only running a conservative 34 degrees advance, on 93 octane E10. Another 5-10 degrees advance under light load conditions, like interstate cruising, would be nice.
Regarding the creeping idle, are you sure the progression holes in the carbs are not exposed at idle (thus releasing more fuel into the engine than it should)? On my carbs when the progression holes were not uncovered by the butterflies the idle was way too low and would slowly die. If I increased the idle with the throttle stops to open the butterflies the holes would instantly be uncovered and the idle would jump very high. The fix was to close the butterflies and instead adjust idle with the air bypass valves. I have all my air bypass valves two turns open and now it idles rock steady at 1000 rpms.
Nicks Forza Ferrari sold me distributor blanking covers when I installed their XDI ignition system: Regards, Gordon
Conversion from carbs? Forget that, do the necessary carb adjustment/repair! They worked fine when new. If the problem is base warpage - probably due to over tightening - true them on a sheet of glass with wet/dry sand paper. That's a common carb "repair" on car/motorcycle engines where the someone was over-enthusiastic with the tightening torque!
I've been fighting a fast idle on my 78 for a year now. It all started when I installed the Pertronix (still uses the distributors) electronic ignition. I blamed the lack of the retard micro switch/P2 circuit. But it turns out that was only part of the problem. I was sure I had a vacuum leak, even went a far to build a smoke machine to help locate it to no avail. When the problem didn't get any better after I changed to sealed throttle shaft bearings along with one throttle shaft and butterfly I decided It had to be something else. So even though the car runs really great and has no trouble keeping up with any stock 308 I decided to check the timing. And low and behold it had to much advance by about 7 degrees. In other words it had 41 degrees lead at 5K rpm. I backed it down and now it idles great between 970 and 1000 rpm with AC off and 940 and 970 with AC on and seems to run a little harder through the gears. If your doing the injection/coil pack mod just because that's great and I envy your ambition but if your doing it because the car doesn't run correctly that's a different matter. While the 2V carbed cars aren't particularly quick by todays standards they still move right along (keep in mind my daily driver is a slightly moded ZL1 Camaro). I've driven mine about 5k miles in the last couple of years with no trouble. Good Luck Barry
Hi all Just spotted these responses - thank you! I’m committed to the conversion now - and part way through it. It will be an entirely bolt on/off conversion - I won’t have to make a single easily reversible change, is my current expectation, so if I ever want to go back to the mystery of the problematic carbs, then I can. Tbh, I just got fed up with trying to fix the problem. Every time away from the garage I would have an idea as to what the problem was, then I’d spend a lot of time on implementation of the solution, only to find it made no difference. I have no doubt that with the right expertise it could be sorted, but that’s not that easy to find - and the full engine management conversion should deal with it once and for all, and will for me make the car more useable - not that I am knocking a well set up carb car - that just seems out of reach for me at the moment.
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