Ok guys, just looking for a little guidance. I think I have most of the kinks worked out but if some one could look this over and go hey dummy take a look at this or that I would really appreciate it.

Here is the back ground info 18 months ago I purchased a Jeep CJ-7 to replace my last Jeep that some mysterious person borrowed and forgot to return. The CJ body and frame were in great condition. The rest was trashed I figured to replace the whole drive train which I have done. The engine didn’t have much power. Since I am in California decided to go with a Howell kit (which is CARB approved 4.3 GM TBI kit a TBI with a 1227747 ECM) but it doesn’t control ignition so I upgraded to a full MSD ignition system.

So the engine ran better but was tired so I figured to go with a crate engine Golen had a bunch of hype and for only $500 more I could get a 4.6 Stroker. Well I installed the engine and I could never get it to run right. I chased phantom vacuum leaks for months and finally went to Craig Moates bought an emulator and was able to tune around a few problems. After 5000 miles it plain just died. The autopsy showed a very sloppy build along with a non friendly cam.

So I had the engine gone through by a local builder and he set the engine up correctly. The specs are as follows 4.7 liters, bore 3.935, stroke 3.895, 9to1 compression, Clifford Intake with TBI adapter, Clifford EFI cam, Clifford headers, MSD billet distributor, MSD 6 CDI, Yellow Tera Roller rockers and timing chain. (and for the Jeep aficionados the trans is a NP435 a Saturn 27% overdrive and Currie 9 inch front and rear axles with 4:10 Gears on 33 BFGs on a 4inch RE lift)

So now the thing runs very well. Fuel pressure is 12 PSI on a liquid filled gauge on the fuel line. Great oil pressure and the vacuum follows the AFR gauge as it goes up and down but typically its 15-17 inches.

Though there are a few quirks I am having some difficulty with. One is I set my TPS voltage to 0.54 volts(with a Fluke DVM) this will show up as 0.55 or 0.2% in Winaldl and some times it changes to 0.7. I have reset this several times and it still seems to do what it likes.


The next thing is the idle when its cold it will be around 600 RPM when it warms up it will hover around 800 +or- 100. Some times the idle will hang around 1400-1500 RPM and then roll down to 1000 RPM. I have reset the idle air numerous times and occasionally it seems to do what it likes.


The next thing is starting from a stop light it seems it could use a bit of enrichment.

And the final thing is it is one cold blooded beast. It runs like crap till it comes up to operating temp. Is there anyway around this? I mean this thing will cough and sputter badly. Since I leave for work at 4 AM I am getting concerned that the neighbors will do the pitch fork and torch thing like in the Frankenstein movies.

Any pointers would be greatly appreciated.


Thanks George AKA Dummy

 

Sounds like a great build. I wish that you were able to control the ignition with your ecm. I am surprised the kit could not control that. How much control do you get with a MDS 6 CDI?

Anyway, I had success with tuning by starting with the IAC counts. The high idle points to the throttle follower settings with the IAC. I got an EBL, so I am not sure if your code is completely compatible. Once I got my IAC counts between 5-10 at idle and op temp, it ran significantly better.

The fact that it is running like crap cold sounds like the open loop needs to be tuned. You need to look at things like the OL - AFR vs rpm vs Map tables. There are also a ton of variables that deal with temperature at start up. Bottom line it sounds like your VE tables are not tuned in yet.

I'll try to find time to take a look at your logs and hopefully some more educated people on the 1227747 ECM tune in.

 

Thanks graebz28. In CA the only TBI that is C.A.R.B. approved for a Jeep is the Howell kit which controls only fuel. The stock distributor is used along with a vacuum operated Coolant Temp Override switch. Since I am leaving LA for the Midwest in a few months I will get around to doing the knock sensor, ECS and ignition module. But for now the MSDs spark curve matches the stock one pretty closely.

Right now I figure keep it simple stupid and work the fuel side then I can address the ignition.

I have both tuner cat and tuner RT. I feel a lot more comforatable in Tuner Cat but I am still fumbling my way around. Once I get a toehold I learn pretty quickly. I have read most of stickys here but the more I read the more cornfussed I get. Which is why I am asking someone to kind of point me in the right direction. Once I can sperate the wheat from the chaff I am usually ok.

I am still trying to wrap my head around the logic of it all which at this point I think I have a rough idea. But I cant connect the dots yet. But I will get there.

And yes its an great machine (sleeper this time till I leave LA, I dont want another Jeep stolen) My low low gear ratio is 116-1 which puts me at about .6 miles per hour at idle and maybe close to 1 MPH reved up. My finnal high is somewhere around 3.73 to 1 which gives me a comforatable cruise speed.