Any Holley Pro Jection experts out there

Finally got my rig running (barely). I'm having issues with the Holley Pro Jection system, and thought maybe someone here has delt with it before.

Here goes:

From idle to about 2700 RPM it runs good whether under load or no load. Above that RPM it starts running rough whether under load or not, and sometimes, it backfires out the exhaust, depending on how much to the lean side I adjust the mid range pot. Even when I go full rich on the pot (clockwise) it still runs rough.

I adjusted the throttle position sensor to the recommended voltage and the voltages are correct from idle all the way to WOT.

I checked fuel pressure and it is at what Holley recommends (13 psi small block 18 psi big block) measured at the throttle body. I have it set at 14. The throttle body has 80 pph injectors, but I also have a set of 57 pph injectors, and I get the same basic result with either set. The pressure stays steady at 14 even when opening the throttle wide open.

I also checked for possible vacuum leaks and found none.

Now reading through the installation manual, Holley recommends a coil signal conditioner, when running a point type distributor with a high output coil, if the engine starts running rough at high RPM (which it is). Since I'm running an HEI distributor, does anyone think this may be the problem or is the Pro Jection not really designed to work with a V6 (4.3 Chevy).

My thought was maybe since there are 2 less ignition pulses from a 6 cylinder that possibly it won't work right.

Thanks

 

Called Holley tech support, and apparently this unit is not designed to run on a 6 cylinder. The fuel map is designed for a V8, so no matter what i do it's not gonna run. Oh well back to a carburetor, till I can gather stuff for a GM factory system.

 

Bummer John.
Seems Holley would offer a setup for the V6.

 

I'm not convinced that's your problem John. Unless something changed since I did my research on the ProJection system, it shouldn't matter whether you have a 6 or 8 cylinder, even or odd firing. I can't remember who exactly (maybe Patrick??) but someone here put a Projection on their 225 and got it to work better than you describe... Anyone????

 

Yep. That doesn't sound right. They offer an inline 6 set-up for the 258. Are there different part numbers for that computer?

 

Member "msbweiland" got his projection to work on an odd-fire v-6. He has several posts about it here. Maybe you could email him or maybe he'll see this post and leave a comment. I have a projection too but I haven't installed it yet. Both of ours are the analog type. From what I've learned, the injection pulses are controlled by the frequency of the ignition signals, so it really doesn't know how many cylinders you have, it just knows when they fire.

 

Well, I have a Chevy TBI on a 1975 odd-fire.
It is a different set-up than Pro Jection.

It runs off of a Holley racing style crank sensor and is a closed system.

I had a chip made and the system custom adjusted by
Norm at Affordable Fuel injection.

It was in a Nissan 4x4, but is now mounted in my CJ6 project.

I have not run it for about 18 months-- but it ran OK.
No flat spots from idle to 5000 rpms-- Good even torque.

Just has a skip when the system goes from open system to closed system as the engine heats and switches over to a closed loop to read the O2 sensor and MAP sensor data.

I will rewire it into the CJ6 and run it in about 4-5 months I suppose.

Back a few years ago some used to say you could not fuel inject a Buick v6 odd-fire.

 

Well after putting the carb back on I am still experiencing the same problem. :? Has me baffled now. I never even touched the engine while I was working on this project, so it seems weird now to have a high speed problem. But on the positive side, it sounds like the pro jection will work. I tried changing out the module in the HEI and it still runs rough at high RPM. I guess my next step is to look at either the coil or the plugs as a possible cause. It just seems so weird for it to run fine below 2700 RPM then start runnig bad above that. I did take the distributor out while the jeep was down, but being an even fire engine it shouldn't matter where I drop the distributor back in as long as the firing order is correct, since the terminals are evenly spaced.
I will get it to run right with the carb, then re install the injection. I might also look into what a new distributor costs, but it's hard to find a non computer HEI for a 4.3. Does anyone know if the 3.8 Chevy distributor will work in the 4.3?

 

DO NOT use a 200/229 (Chev 3.8) distributor in the 4.3. The 3.8 is a semi-even fire motor whereas the 4.3 is an even fire motor. The degrees of crank throw are different enough to cause problems. I watched a guy scatter a 4.3 because of this. Granted he was running the snot out of it at the time but there were enough detonation issues that he pounded the rod bearings right out of the thing. I bought a bunch of 4.3 stuff from him after the fact and got to inspect the parts that came out of the motor, at least what was left, and it was definitely a detonation/timing issue that was the root cause of the damage. Nickmil.

 

Nope. I have the recommended fuel pressure at the throttle body.

Nick. I did some research last night about it and found out just what you told me

I think I know the problem. I forgot about one mod I did while it was out. I reclocked the distributor cap, because I am using the HEI housing from a V8 chevy with the 6 cylinder guts in it. The 6 cylinder cap indexes in an area that causes the plug connector to be 90 degrees from where the vacuum adavance canister is, instead of 180 degrees like a normal distributor. Well this puts the plug facing the carb, which was fine with the 2 BBL, but it was in the way with the Throttle body. I think when I re-clocked the cap I didn't make sure the terminals coincided with the pick up coil/reluctor which is causing a severe out of time condition once the mechanical adavce weights start to operate (which is at high RPM). Boy do I feel like a moron.

I'll try to get it going right with the carb hooked up this weekend. After I make sure it runs good with the carb i'll throw the injection back on it.

 

I run a Holley Pro-jection on a 4.3 and have for over 10,000 miles. It runs excellent no problems.

 

Yeah I got mine working right. It was a distributor issue. I reclocked the position of the cap, but forgot to reclock the pickup. ops