So here's the deal, pretty much since I have done my fuel injection conversion, I had had what almost sounds like a slight, very fain miss when engine load is very light. (like when coasting down a slight grade where the throttle is close to being closed) Basically high vac areas where timing is higher. When I did my conversion, I never did re phase the distributor pickup. I figured it was simply because of that. I procrastinated for several years and then last weekend I for some reason decided to finally do it. I followed the instructions from from a few different places. I pulled the dist, reluctor, drilled and tapped it for a set screw, and re phased it. I put it back in as close as I could to where it was, knowing it was going to need to be re timed. I run it down the road and back to get it warm to set the timing. I could tell the timing was off and it did not run well. Once I got back, I shut it off, disconnected the bypass wire and tried to restart. I had a hell of a time getting it started. Then when it did start, it would run about 20-30 seconds then die unless I held the throttle open. I could not even move from the seat to the engine before it would die. I placed small shim between the throttle arm and stop screw to try and hold it open a little. I was finally able to get it to run long enough to try and set the timing. I would watch the timing mark and after a few seconds, the timing mark would disappear, the engine started running super crappy and then die about a second later. I would have to restart (not easy) and then run up front and get a few seconds to try and set the timing before the mark would disappear and engine die. After a few times of doing this I think I was able to get it pretty close to zero. I shut it down, unhook the battery, reconnect the bypass and then test run it. It seemed to run somewhat ok.
I drove it down the road and back but it did not feel quite right. It has now started to want to have a slight backfire when shifting gears, and now for some reason, DFCO does not want to engage all the time, and when it does, it exits it sooner. Idle was also not the best. I double checked the phasing and it seemed ok. I thought maybe I hit or damaged the pickup somehow. So I order a new one up from rockauto and put it on yesterday. Well that was a failure, it would not even run on that pickup. When I tried to start it, it would kick back, and when it did finally start, it was very badly, popping and backfiring out the exhaust and would not rev up. Now I had that exact same issue when I first did the conversion years ago, and it was the cheap parts store pickup that was in the distributor. I installed a top of the line napa pickup and all was well, and has been well ever since. So I pull it back out again and put my old pickup back in.
It was hard to start but finally did. It ran a little poorly for a few min but then started smoothing out as it warmed up. I drove it down the road and it it still does not feel right. DFCO does not want to engage and it still has a slight backfire when shifting. Also, since dfco is not engaging, during decel it wil blop blop, blop, out the exhaust. It has never done that, even when everything was running normally. I get back home, and try to set the base timing again, but the engine will only run about 10-20 seconds then die when the bypass it unplugged. I plug it back in, reset the ecm by unhooking the battery and restart. I fool around with the timing manually with the bypass plugged in and just did it by ear and got it back to running a driving about 85% normal, but something is still not right. DFCO is still slow to engage, and does not engage all the time like it used to, I still get a slight backfire when shifing and the blop blop blop during decel.
I think it is all coming back to some type of ignition related issue and I can not help but think it might be the motorcraft dist/pickup. Especially after I re read Dr_Grip's thread: http://www.gearhead-efi.com/Fuel-Inj...t-to-run/page3
So my current idea is to ditch the motorcraft distributor and pickup and try to use a GM based or hybrid distributor. I remember seeing a few threads on a couple different forums where there was a place that could take your carb distributor for any engine, and graft on a GM FI distributor top half (take two and make one) But I can not find any place online that does this. The other option I see would be to buy a aftermarket HEI distributor for my engine (they are all over ebay) and mod it with a 7 pin module just like Dr_Grip did with his ford engine.
I would prefer the TBI style dist top (that uses the 8 pin module) on my old dist bottom, as that way I can use a good quality factory gm pickup and it will be what this ecm had factory.
I am not a huge fan of the HEI coil in the cap distributors, but would run one if I could come out money ahead of above modded dist. Only issue I see is questionable quality of the aftermarket hei distributors and parts (pickup, coil, reluctor, etc..) But I suppose all that could be swapped out for quality parts, assuming stock gm parts will fit the aftermarket dist.
So just looking for any and all input, theories, ideas, recommendations, etc.. Thanks.
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