Calling out Holley tbi guru's need help please

[Michael]

To start out I got this unit used. So my problem could be anything. Straight to the point,
It is hard to start and when it does start it idles good. I have noticed and played with the
fast idle solenoid and when I pull the solenoid up all the way it works great. I have not checked voltage at the solenoid so I have no idea if it is getting proper volage. I know that it works with the tach signal. Now, what wire did you all hook up on the coil? Just making sure I did that right and does this need a full 12volts? again not sure of my voltage.

TPs is good checked with my meter and adjusted to .64 dcv with throttle plate closed. Key in run position and not running.

Okay question 2, when it is running and I give it throttle it backfires through the intake bad, very lean and sometimes the injectors go on and off.....I am thinking the regulator is adjusted to lean but again I am looking for anyother possibilities.

Oh and another question....on wiring the fuel pump red wire to positive and the green wire to ground side of pump? Now it is hard to get the pump to run all the time that way....so if I disconnect the green wire from ground side and ground the pump it runs normal. Now I know the pump is supposed to turn off after a few seconds but once it is turned off what makes it turn on again.

I guess I need to know what the ecu is looking for. I any help is greatly appreciated. Unfortunatley I will not have time to work on it till next weekend. Thanks again.

[Spectre]

Have you checked to see if the throttle position sensor is working properly through its entire range of operation? I'm still working on my conversion, but when I got my system, the TPS was dead. Just got back from the store with a replacement - that can cause the symptoms you describe with backfiring and leaning out.

[ January 02, 2006, 05:51 PM: Message edited by: Spectre ]

[Michael]

Yes I did Spectre the last time I checked it was 5dcv at wide open throttle and moved up smoothly from .64dcv. I will double check it again to make sure I did not miss something.

[ January 02, 2006, 06:14 PM: Message edited by: Michael ]

[jeepzilla47]

the ecu controls the pumps flow by adjusting the ground signal....i dont believe the fast idle works with the tach signal...it is driven off of the ecu and referenced back to the engine temp...the ecu gets its signal for the pump through the pink (if i remember correctly) that is connected to the starter solenoid. do you have any fuel pressure gauges? i installed one on my supply and return lines so i could get the pressure right.....also, do you have it on a 401? if so, it needs to be on the bb calibration...when i had the backfiring problem, it was just a tuning deal..

ps, check your timing...when i pulled my truck avenger and installed the holley tbi, i had to reset my timing...

[janie]

Michael, someone else who might be able to help is our own Joe Guilbeau. He's been running this setup for a loooong time and knows the Holley system well.

[will e]

I have been running the Analog 2bbl version on my Mustang for 10 years and am in the middle of a installation on my Jeep.

1. Which Holley unit do you have?
2. As Jeepzilla said, the Solinoid is not goverened by the tach but is used when the engine is cold. THere should be a brown wire that is hooked to the HOLLEY temp sending unit. This will enguage the solidnoid and send extra gas to the engine when the motor is cold. This is the LAST thing you want to set and only after you have the rest of the unit initially dialed in.
3. The Fuel pump wires are hooked into the ECU. It is possible that you have low voltage issues (but unlikely at startup). The manual recommends using a relay if you think this is possible (The RED power wire is either hooked up to source that is only on when the ignition is or a relay is used to power the red wire from the battery using an ignition only source.).
4. There is a PINK wire that is hooked into the starter solinoid and should only get power when the starter is turning over.
5. That leaves the TACH wire (I forget which color this is)

Did you follow the instructions for the initial setting? I can never remember my system being the cause for backfire.

[Michael]

Good info guys let me get my instructions. Now the pink has to have power too? I am confused. By holleys instructions it goes to ground if using the small block setting on the ecu?

BTW this is the 2d 2bbl setup open loop etc.

Now what does the pink wire do?

And if the fast idle solenoid does not play a factor when starting or first starts....seems I cannot get it to start once started and stopped without it. Without it the injectors do not work.....

Here is what I have:

White wire= -tach lead on coil
Brown wire= coolant temp sensor
yellow wire= fast idle solenoid
red and green wires to fuel pump=red to positive
side of pump green wire to negative side of pump
Pink wire= grounded, by holleys instructions
I am running a relay for the ecu...working
properly.

I have to be missing something. Must be the pink wire......????? Now what does this system do on a battery with less than 12volts?

Thanks guys keep the ideas coming. I really appreciated it.

[ January 02, 2006, 08:52 PM: Message edited by: Michael ]

[Michael]

It is possible that I am fighting two diffrent things...oh and btw

15psi fuel from the pump....but if the regulator is on the tbi unit couldn't it regulate it down without seeing it on my inline gauged.

When I crack the throttle fast....or more than slow the injectors stop for a second....and then backfire through the carb,,,,, like it cannot keep up with the fuel demand. I did not adjust the fuel pressure on the unit.

.

[will e]

Check the pink wire. I am suprised it is supposed to be 'grounded' but I am using the Analog for reference. (BTW, do you have a copy of the closed loop instructions?)

Set the Fuel pressure so that it runs good with the ECU screws in their 'middle' position (midrange especially important). THen adjust from there.

For example, if you have to put midrange all the way clockwise (or close to it) then increase the fuel pressure and turn back the midrange. When I say 'good' I mean so that there is adjustment in both directions from the middle positions.

[ January 02, 2006, 10:42 PM: Message edited by: will e ]

[Joe Guilbeau]

Here are some threads on the Holley Pro-Jection...

I have been running this on my daily driver since 1995.

<a href="http://www.ifsja.org/ubb/ultimatebb.php?http://www.ifsja.org/ubb/ultimatebb.php?[/URL" target="_blank">

http://www.imperialclub.com/Repair/Fuel/Projection/

There is a transistor inside the ECU that is used to supply power to the Electronic Fuel Pump.

Since this transistor must carry the full load for the Electronic Fuel Pump power requirements, it gets hot and eventually expires.

As it gets hot, the heat sink transfers heat to the rest of the ECU thus causing premature aging, and eventual heat related failures.

Now, the placement of the original electric fuel pump supplied with as OEM equipment is a Carter branded electric fuel pump. It was never designed to pump as hard as we require it, if you mount it near the gas tank (as suggested by Holley) it works too hard to pump fuel all the way up to the engine bay, and all of the fuel that the TBI does not use is funneled back to the gas tank in the return line. This means that that little pump is working really hard, being supplied by a transistor inside the ECU that is working very hard also.

Make life easy on both components, use the Transistor to supply the relay signal to close it contacts. Use a relay with an AMP rating to insure that it is not overtaxed.

HINT&gt;&gt;&gt; If you purchase a single throw double pole relay of sufficient current carrying capacity, you can use a single relay to power both of the Electronic Fuel Pumps.

The Number One failure of ECU's is this Transistor, burn it up and you have no signal to run the Electronic Fuel Pump/s.

This is the reason many of the ECU's get hot!

posted March 10, 2004 03:22 PM
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Yep,

However one thing should be made clear about the Fuel Pressure (12-15PSI) this should be used to richen or lean out the system after running correctly.

Pull the plugs, if they are the correct color, then the fuel pressure is right on. Too light (almost white) and the fuel pressure needs to be higher.

Too dark (dark brown or darker) and the Fuel Pressure needs to be lower.

The best way to tune your system is to set it for Small Block operation (rocker switches inside the ECU) and set all potentiometers to mid-range.

Loosen the TPS and adjust as you attempt to start the vehicle. When the vehicle starts, play with the TPS adjustment until the vehicle runs. Now let her warm up, or put a 200 OHM resistor from Block Ground to the temperature sender spade lug connector to simulate a warm engine.

Now, the Idle potentiometer should have a range of adjustments so that you can lower idle and raise the idle. The TPS needs to be set so that the Idle Potentiometer will not kill the engine with lowered all of the way.

The Mid-Range pot needs to set so that at 3000RPMs or so the engine will increase in RPMs as the Pot is turned clockwise...it SHOULD plateau out about 3/4 turns to full CCW position.

The TPS setting is really what gives this the range of adjustments. Each ECU will deliver a slightly different 5Vdc signal to the TPS for a reference voltage so that the position of the TPS throttle plate will cause the voltage divider to give a linear displacement in voltage that is supposed to be consistant with the physical position of the throttle plate from fully closed to fully open.

I am considering a modification to my circuitry to provide a DC-DC power supply (Oil Field Grade) to provide a 12Vdc to 5Vdc voltage conversion to supply the TPS with a better regulated signal.

This way the TPS (the only signal that is really controlling the ECE) is right on.



Member # 2786

posted March 11, 2004 10:12 AM
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quote:
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Originally posted by djmac:
joe
my exhaust always smells rich. when i pull up to a light an idle you can smell it in the cab. i have it leaned out the best that i know. do you think that the fuel pressure is the culprit? [14-15 lb] there is no smog equipment on my 460 at all and someone told me the smell is because of that but to me it smells rich and the plugs say so too. i have a hard time getting it to idle right also. if i lean it out enough to get a good idle it is too lean when at wot. open the main to get a good wot setting and i have a surge at idle speed.
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Yes, I think tht you are on the money, the fuel pressure in the Pro-Jectiion systems is used to adjust the lean and rich characteristics of the mill.

The system has only the position of the throttle plate to control the injectors, and there needs to be a "Window" set up so that when all of the pots on the ECU are set to mid-range the system is at the exact center of that "Window".

If the TPS is rich at when set at the middle of the "Window" then the system will always run...(fill in the blank here...RICH).

So initial setting of the TPS at idle is extremely important, get this set right and everything else will fall in place.

Sounds to me like you are Rich at idle, and are using the fuel pressure setting to compensate.

You must set the big block rocker panel switch and get the initial settings right on the TPS before going any further. Then everything will track nicely.

You may want to consider getting one of the exhaust gas analyzers (to display the 14.7 whatever ratio) and use this to set the initial TPS settings at idle.

Then your adjustment ranges should be pretty much right on.


posted March 11, 2004 04:34 PM
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quote:
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Originally posted by djmac:
sound like i am getting somewhere! i am not sure where the dipswitches are located. Is it located within the large unit (heat sink) in the cab? should i set this to small block then set the tps and go from there to start?
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Small block setting is for 360 Cubic Inch and smaller.

Large block setting is for 360 Cubic Inch and larger.

There is a bank of rocker panel switches inside the ECU, removal of the end plastic pieces reveals them.

See the manual for further details.



posted March 15, 2004 12:48 PM
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quote:
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Originally posted by djmac:
Has anyone found a substitute for the projection fuel filters? a fram equivalent? also i bought the aquistion software only to find out that it will work only on windows 3.8. do you guys know of anyone with software that is reasonably priced for later versions of windows? i have the analog tbi but it would be interesting to see whats going on.
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Any fuel filter will work as long as it plumbs into the gas line...

What aquisition software are you speaking of? Is this made by Holley for their Digital Pro-Jection systems?

As far as I know there is no version of Windows 3.8???

You cannot use the digital software for the Analog ECU, it ain't gonna happen.

The Analog ECU uses simple Operational Amplifiers to relate to the voltages sent by the Throttle Position Sensor and the voltage dividers (potentiometers on the face of the Analog ECU).

For the analog systems, you only need one of those Oxygen sensors and the ratio display to place the TPS in the proper ratio of Gas to whatever it is called (stiochrometric whatever...) at something like 14.3 or 14.7.

This should be on a warmed up engine, with all pots set at mid-range, with the voltage that the ECU is recieving from the Throttle Position Sensor at about 0.63-0.68 Vdc.

If the engine does not like this range go ahead and use the Oxygen sensor to set the initial TPS setting to where it is in the proper range.

That way, the TPS is sending the Operational Amplifiers the voltage in the "Middle" of the window of the +/- inputs, and since all the potentioneters are in the center position, the Operational Amplifiers for the Choke, Idle, Mid Range, Power and Accelerator Pump are centered so that the voltages that they report to the operational amplifiers can go ahead and modify the pulsing paramaters of the fuel injectors.

This is all that is really happening with this system, it is soley dependent on the initial set up of the TPS which in turn sends an Operational Amplifier a voltage reference poit, which in turn modifies a Pulse Width Modification circuit which in turn gives the injectors the correct signal (in accordance of where the throttle plate is opened to) to give the correct fuel delivery spray volumn.

The Fuel pressure is what is used to give the rich/lean characteristics for the engine burn, however if the system is not set up initially correctly, then all is lost.

Just tune by ear the TPS setting at idle when the engine is warm, with the pots set at mid-range, and you will be pretty supprised at how close you can get.

Thats how they do it with carbs....not too much difference, except that there are no jets...only fuel pressure and a somewhat linearincrease in fuel delivery as the throttle plates are being opened and closed.


The Holley Pr0-Jection throttle plate and TPS should be set according to the following procedure.

Removing the spring from the throttle plate so that it will not try and open the plate, use the front idle adjustment screw on the front of the TBI to close the Throttle plate completely.

Set voltage to 0.63Vdc, now open the throttle plates a bit like you would a carb so that the engine starts and runs.

The thing is, all engines will want to run a bit different, so here is where you ground out the Temp Sensor (brown wire) and tweak the TPS until the engine runs great with all pots set to mid-range.

As you finally get the TPS tuned in to your vehicles engine, go smell the exhaust...if it is rich lower the fuel pressure, until she smells sweet or go buy a meter to read the exhaust.

Don't worry too much about using electrical doo-dads to monitor the system, tune it by ear and you will be spot on.

Forget about using software to monitor it...it is an analog operational amplifier system designed to do one thing and one thing only...vary the voltage to the injectors soley dependent on the voltage that it gets from the TPS...that is all that this system can do.

Get the TPS intitially set up correct (by ear on a warm engine) with all of the pots in center position, and you have just dialed it in.

Pack in some dielectric grease in the TPS before installation to keep out the water.

[ January 03, 2006, 04:11 AM: Message edited by: Joe Guilbeau ]

[The PIG Smith]

WOW!
I am gonna need a sandwich and something to drink before I can finish reading all that! &lt;just kidding&gt;

Thanks Joe for posting this info.
As the Tech Library is dated and somewhat limited and searching this forum is not the best as articles seem to expire,
I've cut and copied this info to a Word doc to save for when I perform my Holley Pro-Jection conversation.

Could you give some tips on what Holley Pro-Jection unit to buy and what to look for?
I've been lusting after a TBI setup as I struggle with carburetion issues consistently

[Michael]

Man thanks for the repli es, so far it has helped a lot.

So, I hooked up the pink wire to the starter relay and it starts like a champ now. I am still unsure why the instructions say to ground it if in small block mode. Anyway it worked.

Now to another question. The tps checks out fine in the voltage range. So tell me this
why when I hit 1/4 throttle it will not go smooth. The injectors shut on and off. I tried messing with the tps to see if it changes while doing this...but no change.

Now could this be a tunning thing? Or is it a sign of a bad tps? Again any input is greatly appreciated. Now that it starts I have not tuned it yet. I just need to make sure I am not chasing another wiring issue, and confirm it is just tunning. Many thanks....

[will e]

Hijack (sort of).
I just hooked mine up and no fuel from the injectors. I took the pink wire and connected it direct to the battery while a buddy cranked the engine and the injectors fired. I put it back on the start solinoid and it didn't work (I only have 9 volts there for some reason).
WOuld this keep it from starting at all? Will the injectors not fire at 200rpm from the tach signal?

[will e]

Michael, glad you got it running.

Sounds like you need to play with the settings.

[Michael]

Will e I found the other day that anything less than 11 volts the injectors would not fire. Strange you only have 9v there. Because it is a direct link to your battery. Mine was 12.75 tonight and it fired up great. Now are hooking it up the one that only gets juice in the start position? The other terminal only had 4.8volts on mine. I want to say that goes to the resistor wire and to my coil. That would be incorrect. Good luck....and thanks again.