Problems with Holley Pro-Jection 2D System

[Michael]

Let me ask you all something here. Have any of you called Holley Tech? To me the only things that will let it run rich are these. Now I may be missing something. I have had mine on for about 3 years now so....and it is the old style unit but runs great.

Coolant temp sensor. If it reads cold when it is hot it could trip the fast idle solenoid, or just tell the ecu it is cold and it will change the fuel trim making it add fuel to the injector. Although since you pulled the wire Tad and grounded it and it did nothing I suspect that was not the case,

Now having fuel delivery issues. When I installed mine I put new lines from the tank. And then new lines from the return....same size I think 3/8 which is one size bigger that the factory 5/16 line if my memory serves me correctly. Now if you have a restricted return line you will run rich until it gets past the bad spot and pressure reduces.

Now I highly recommend fuel gauges on the inlet fuel line and the return line. I just have one on the inlet side of mine. Which everyone is different due to altitudes but mine is running around 9.5 psi ....that is to pass inspection. I would put a fuel pressure gauge on it before I went any further.

Let me ask you this, when you tuned it, how much is the idle screw screwed in before you set the tps? Or did you set the tps before you touched the idle screw on the throttle body?

Just some thoughts to get your brains rolling....I have only had one issue with mine...that is a lean back fire through the intake on hard acceleration. I does it from time to time. But I got most of it out of it and it was all tunning related.

[jdaniel83]

As far as the fuel lines go I ran new 3/8" fuel lines from the front of the tank to the throttle body for both the feed and return and I have not put a fuel pressure gauge on it yet, but I'll prolly do that after installing the new TPS.
I do think you bring up a good point as far as adjusting the TPS and Idle because I adjusted the Idle before I did the TPS, but the Idle didn't seem to change once I adjusted the TPS so I left it alone. But I wonder if it could have something to do with the TPS going out. I also experienced a back fire through the intake on hard acceleration a couple times before it completely crapped out on me but I thought it was due to small adjustments too.

[Tad]

Let me ask you all something here. Have any of you called Holley Tech?

Yes, they were of little help.
Idle was set prior to TPS (p32-33) but having messed with it many times I'm fully prepared to go through it all again. It's not that hard I just wish they gave you easier jump in points for the volt meter, I'm thinking about cutting in and adding my own.

I'm slammed here for the rest of the week with a really big order but will start from sctratch when I install the reman dizzy this Saturday.

The reason I am focused on the tach signal is that I have had this little glitch in the ignition for the last 2-3 years. Even prior to the 2D system I could watch it on a tach and every couple of min it will bottom out.
Like poof, down to 100 rpm.
Not enough to kill the engine, it comes right back, but maybe enough to fool the ECU into thinking something else is going on.

EDIT:
What fuel pressure gauge is anyone running?

[Michael]

Tad you may be on to something with your distributor issue. Although the tach signal is telling the ecu when to fire the injectors, I am not sure if it would make it run rich but possibly make it fire at the wrong time...that is a long shot though. Anything is possible.

I am running a small fuel pressure gauge, I used a cheapo from the auto store but it was crap. Try and find one that is fully contained, glass lense etc it will last longer. But anything is better than nothing.

[Tad]

Tad you may be on to something with your distributor issue. Although the tach signal is telling the ecu when to fire the injectors, I am not sure if it would make it run rich but possibly make it fire at the wrong time...that is a long shot though. Anything is possible.

I am running a small fuel pressure gauge, I used a cheapo from the auto store but it was crap. Try and find one that is fully contained, glass lense etc it will last longer. But anything is better than nothing.

I might have this wrong so correct me please.
If I install a gauge, that just tells me what pressure I am running to the injectors?.
Correct?
If I need to adjust, I need a pressure regulator?

I can adjust pressure to the injectors at the top of the throttle body, but a gauge prior to that tells me what?
I know it tells me the PSI, how does it tell what is going through the injectors?

I've messed around and backed that allen nut off (7 turns one time), it did make it leaner but would not deliver any more fuel at high rpm's.

I'm not at a loss or giving up.
I'll be in 'Cruces with the jeep even if I have to go back to a 2V

[Chevelleguy]

The pressure in your line between the regulator and the pump is the pressure at the injector. The TBI has a built in regulator (you know that as you have tried to adjust it). The more pressure at the injector, the richer it will run because the injector is open a set length of time no matter what the pressure.

TBI's generally run in the 12-20psi range but the pump is capable of producing 60-100psi

[Tad]

The pressure in your line between the regulator and the pump is the pressure at the injector. The TBI has a built in regulator (you know that as you have tried to adjust it). The more pressure at the injector, the richer it will run because the injector is open a set length of time no matter what the pressure.

TBI's generally run in the 12-20psi range but the pump is capable of producing 60-100psi

Got it.
Thanks for clearing me up.
I'll get something with a regulator if the new dizzy does not help.

[jdaniel83]

I may have to do the same to mine. However, I believe I just figured out that the TPS is certainly one of the things causing my GW to run so badly. I unplugged the TPS and started up the Jeep and it would idle on it's own and actually ran considerably better with less smoke/rich exhaust. It still doesn't run that great, but hopefully when I change out the TPS tomorrow it will make it run like it should.

[jdaniel83]

Another quick question, when replacing the TPS the Holley instructions that come with the new TPS say to take the whole throttle body assembly off the engine. Is this really necessary? I'd figure it would be a lot easier to take the two screws and retaining clip out and pull the old sensor off and install the new sensor while it is still on the manifold.


Has anyone else done this when changing out the TPS?


Oh and I would disconnect the throttle linkage before doing any of this to avoid any movement of the throttle while changing the TPS out.

[Sambo]

yeah holley units are set at 15 psi,or should be...i remember reading that in the destructions

[jdaniel83]

so here's an update...
i installed and adjusted the new TPS this afternoon and started the jeep up. it idled on it's own but was still running kinda rough and blowing a little smoke and smelled rich so i turned the MAIN knob all the way down and it started running better. i still think it's getting way too much fuel though. i think it's strange that it wasn't getting too much fuel before the TPS went out. do yall think it's a bad ground or do i just need to mess with the regulator on top of the throttle body till i get a good mix?

[Tad]

...do yall think it's a bad ground or do i just need to mess with the regulator on top of the throttle body till i get a good mix?

I'd certianly make sure they are all good as far as the grounds go.

Another thing I came across in searching was ignition types.
I didn't mention it since I run a standard GM HEI.
There were a good deal of questions/problems reguarding MSD boxes and such.

What ignition setup are you running?

http://www.google.com/search?hl=en&c2coff=1&safe=off&q=MSD+Holley+Projection+problems&btnG=Search

[jdaniel83]

I just have the stock ignition system with an Accel Super Coil. I haven't been able to work on the Jeep because I've been sick but I tried to take it out last night and although it was idling ok if I gave it any gas when it was in gear it would bog down and die. So I'm kinda lost right now. Any ideas?

[Michael]

so here's an update...
i installed and adjusted the new TPS this afternoon and started the jeep up. it idled on it's own but was still running kinda rough and blowing a little smoke and smelled rich so i turned the MAIN knob all the way down and it started running better. i still think it's getting way too much fuel though. i think it's strange that it wasn't getting too much fuel before the TPS went out. do yall think it's a bad ground or do i just need to mess with the regulator on top of the throttle body till i get a good mix?

Check your fuel pressure.

[Chevelleguy]

After you do that, you need to start all over with the ECU adjusting process since you have been messing with the knobs. You can't just turn down the MAIN and call it good. It moves the whole fuel map up or down.