Mopar 318 5.2 gm tbi swap and 4.8 Jeep

New to the forum though I’ve been reading lots here for some time in preparation for this swap. I have a small block Chrysler 318 in a 67 3/4 ton dodge 4x4 pickup (w200 power wagon).

I pulled a sbc tbi, wiring harness from a 86 or 87 k5 blazer, and all the sensors out of the junk yard. I have a 7747 ecu with a 5.0 auto bcc. I bought the moates auto prom kit but I had an issue with installing the adapter to the ecu board so I’m still working on that. I think I will likely need to go get another 7747.

Ive searched the forums but i haven’t seen anyone with a gm setup on a sb mopar. I put all the parts on and got it running. After some heart ache with the timing I decided to go fuel only with the gm system. I thought that since a sbc 5.0 probably flows better than a sb mopar that a 5.0 bin/chip would do the trick. However it hasn’t worked well. The idle and slow torque is great but there is lots of hesitation when shifting gears (manual transmission) and when coasting before a turn. Maybe b/c the bin is for a auto transmission? Anyway does anyone have a good sb mopar starting bin? I figure I will have to start with a 5.0 manual bin and work my way up but if someone has a shortcut I would appreciate it.

Im also looking for the same thing for a 4.8 Jeep motor. My brother upgraded his engine and now the 4.3 bin file is not hacking it.

I have not used the 1227747 for fuel only.

I wonder if there is an aftermarket Chrysler distributor available, that would allow the 1227747 to control both fuel and spark?

I found a Hot Rod article where a Chrysler distributor was converted to GM HEI: http://www.hotrod.com/articles/conve...ion-to-gm-hei/ The Hot Rod article uses the 4 pin GM Ignition Module. Instead of using the GM 4 pin ignition module in the Hot Rod article, using the GM 8 pin ignition module will allow using the 1227747 for timing control. The 8 pin ignition module requires using a remote mounted TBI coil.

Are you up to speed with TunerPro RT to data log? The "BEST" hacking tool for TBI is a data log.

dave w

Some screenshots "HACKING" the 1227747 using TunerPro RT data logs.

dave w

Thanks Dave! I do have a Chrysler dizzy that I converted to allow the ecu to control. Basically removed the vacuum advance and locked the mech advance. The reason I went fuel only is because before I thought i was going to tune the Timing on the stock chip wasn’t setup well for the mopar.

I have data logged with TunerPro and I’m working on data logging and tuning at the same time. I will use that spreadsheet that someone posted under the 7747 sticky that uses the logged blm value to adjust the fuel tables.

Can you help me understand the main fuel table vs the second fuel table in TunerPro from the 7747 definition?

The 1227747 fuel tables can be confusing. To simplify the VE tables, I add VE2 values to the values in VE1, then ZERO all the values in VE2. Add VE2 RPM values to all matching RPM's cells in VE1. With tunerpro Version 5, VE2 will accept ZERO's, but usually shows a value close to 5 after saving all ZERO's in VE 2.

The reason for adding all VE2 values to VE1 allows all VE adjusts to the VE1 table.

dave w

Thanks again Dave. That is exactly what I needed to know. Really appreciate your help. Happy holidays.

So I got the ecu tuned pretty well. The blm values all return 128 or very close to it (130 ish). However I can’t seem to get the idle down. It likes to stay around 800 rpm and I would like to get it down to around 650 or 700. All the target idle values are set accordingly but it can’t seem to get down that far. The idle vacuum is also around 40 Kpa which seems high to me also. Is there a good tuning sticky for the 7747 I could review? I’ve read through several tuning concept pages but nothing specific to the 7747.

Thanks again in advance

so it's been a while and I did get this worked out fairly well. I realized my idle problem was b/c when the logger is plugged in the ECU goes into diagnostic mode. once I unplugged, all good.

So I am having a new problem. I got the truck all set to run on the road. It runs great on the flat but when I pulled a BIG hill, it was doing fine for a while then "coughed" and started seriously overheating.

The slope is about 4 or 5% then goes up to maybe 8 or 10%. When I hit the steeper section I started loosing speed and put my foot into it maintain speed. this is all about 3200 rpm. the engine coughed about 4 times then the temp gauge shot up to 250 degrees. I pulled over and let it cool. I determined that the fan clutch was shot so I went and bought a flex fan that I installed. tried it again and got the same result.

so I think when I tuned it I just did not put enough load on the engine through enough different rpm ranges? is there a point in the 7747 ECU that it goes into Open Loop? is that my problem? any help would be amazing! I do plan on logging it again later this year on that same hill to see if I can get it better tuned with a load.