Duster 383
Well-Known Member
Who has one??? What do you have ??? Have you had any problems??? How hard /easy is it to tune??? ....go
Throttle body injection
- Thread starter Duster 383
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67Dart273
Well-Known Member
I first found an aging Holley "Pro-jection" on CL. It worked but not very tuneable. Then I found a 4bbl Holley Commander 950 which is OK except it does not "self learn". The original Commander 950 system I bought off CL. I think I paid 300? for it, turns out this was a steal
I upgraded the ECU to Holley HP. That turns it into the forerunner of the Avenger/ Terminator, in other words it uses the Commander older style 4BBL TBI unit, but the HP computer
The thing is, later, this can be converted to multiport, and I could even keep the TBI unit for a throttle body.
I upgraded the ECU to Holley HP. That turns it into the forerunner of the Avenger/ Terminator, in other words it uses the Commander older style 4BBL TBI unit, but the HP computer
The thing is, later, this can be converted to multiport, and I could even keep the TBI unit for a throttle body.
Duster 383
Well-Known Member
The Holley sniper did look like a good unit can't wait to hear from some of those guys
There is a thread here on the FiTech: FiTech EFI system | For A Bodies Only Mopar Forum
Aussiemopars
Well-Known Member
Holley sniper on a 383 in a 69 Cuda convertible.... 
. It has been really fun to play and tinker with and tune. When I first got it going and running and "tuning" by itself, I thought I got it pretty close. Then I went and got a pro-tune on a Dyno with the optional USB cable and used the software that comes with it on the SD card. Got an extra 25 HP out of it. Basically a stockish sort of motor. I had an issue for a while where the IAC valve wasn't doing its thing and the TPS wasn't zeroing. Turns out I got a bit of moisture on it when I was hosing down the engine bay. Holley must of used some cheap *** sensors. Replaced the TPS with a standard GM sensor, cos that's the type of sensors they use, and all good and back to normal. Running with the timing control as well. It will control up to about 20 degrees of timing advance I think. My 2 cents... yeah definitely worth it. Definitely use an in tank pump as well if you can and don't try and use the Fuel Command Centre, that's just half assing it I think.
. It has been really fun to play and tinker with and tune. When I first got it going and running and "tuning" by itself, I thought I got it pretty close. Then I went and got a pro-tune on a Dyno with the optional USB cable and used the software that comes with it on the SD card. Got an extra 25 HP out of it. Basically a stockish sort of motor. I had an issue for a while where the IAC valve wasn't doing its thing and the TPS wasn't zeroing. Turns out I got a bit of moisture on it when I was hosing down the engine bay. Holley must of used some cheap *** sensors. Replaced the TPS with a standard GM sensor, cos that's the type of sensors they use, and all good and back to normal. Running with the timing control as well. It will control up to about 20 degrees of timing advance I think. My 2 cents... yeah definitely worth it. Definitely use an in tank pump as well if you can and don't try and use the Fuel Command Centre, that's just half assing it I think.
This is long winded, but you asked and I want to give you my honest experience. 71 Demon 440. Solid roller cam, Edelbrock aluminum heads, Eddy RPM intake. I am running the Sniper EFI with the Stealth 340 fuel tank and the Sniper controlling timing. Keep in mind that I by no means am a guru with this stuff. Holley's tech and Jon at Pace Performance where I bought the system were good to work with. There is some tuning to do with the system if you want but over all the base settings that Holley gives you will work but just not be optimized for each vehicle. You can configure the timing etc to your needs. The big thing with the self learning and only thing it changes is the fuel table. I installed the unit last spring. I had some issues with the system. Initially I was running an MSD billet distributor. The first issue I had was the unit would go full lean on the AFR. I at first thought that this was my own fault as I didn't have the car on the road initially after installing the system and thought condensation had damaged the sensor, so I bought another O2 sensor with a heat sink. But after installing the 2nd O2 I still had the issue of going to 36 to 1 AFR, this caused the unit to pour fuel trying to compensate. I contacted Holley and they wanted the unit back to trouble shoot it. Mine had a bad ECU which was causing the AFR issue. The 2nd O2 sensor tested good. This was remedied under warranty and did have a quick turn around so Holley's support here was good. After installing the repaired unit the car would drive but I was experiencing a lean spike from 1800-2100 rpm and this was the cruise range. Any slight throttle change caused it to spike lean and stumble before it corrected. I thought initially that maybe it was electrical interference as the system would command 60-90 pph fuel flow at 50-60mph. Now the weird thing was that 65-70mph it only commanded 40-60 pph. I made sure all wiring was clear of high current wiring but still had the issue. Initially I was using the coil driver included with the Sniper. I had researched and found the MSD distributors were creating interference issues due to the magnetic pickup, which Holley said would work with the system. I then purchased the Holley dual sync distributor which with the aluminum heads is not a straight bolt in due to interference with the head. Its a stock length distributor but a larger diameter so I had to clearance the head in that area. Still had the issue. I then installed an MSD 6A ignition box thinking there was something funky going on with the coil driver that Holley includes with the Sniper. Same issue. By this point, which is fall, I am ready to yank everything off the car and go carb. But I had one last thing to try. Initially I had my fuel system set up pump to regulator with return back to tank then dead headed to TBI with no return off the TBI itself. Everyone including Holley said this was ok. I did not use the regulator in the TBI due to the higher output of the Stealth 340 tank setup and having been told the built in regulator would not be able to keep up. Anyway I removed the built in regulator routed full pump pressure to the TBI with a return to the external regulator from the TBI. This made a night and day difference in the operation. Now the system commands 25-35 pph at 55 where I was having the high commanded fuel flow. The car does run a lot stronger all the way around with instant response to any throttle changes. Another issue is finding a clean power signal which I couldn't thru the ignition switch, from start to run thru the switch it would lose power and the system would reboot. This is not due to Holley but the way the car shifts electrical thru the ignition switch. Mind you some of these issues were due to my own lack of knowledge and experience. I can tell you that now I have it sorted out I cant wait for warm weather again.
I did take the car to the track before getting the fuel sorted. Which I haven't done in 30 years. The lean stumble did not show up under full throttle even before getting the fuel situation fixed, only slight throttle changes. I run a 3:54 gear with 28" MT sportsman SR. I ran a 12:78 best of 2 passes. But I did discover that I did not have the settings correct for the Dual sync distributor and was 11 degrees short on total timing. Now that I have everything sorted and a little work on my part, I do believe it will turn low 12's high 11's and be able to drive the 40-50 miles each way to the track. I have had the car on the interstate and have no issues cruising with traffic at 70-80mph. Now that I have the kinks worked out I am very happy with the car, just some bumps and bruises along the way due to my own ignorance. I do think the system outside the bad ecu would have operated fine if I had the fuel system configured correctly for my application. I do also believe the MSD distributor along with the coil driver included with the Sniper system would have worked as advertised with the fuel system configured as it is now. Yes there were added expenses but I feel these were due to my own fault. Hope this helps you out.
I did take the car to the track before getting the fuel sorted. Which I haven't done in 30 years. The lean stumble did not show up under full throttle even before getting the fuel situation fixed, only slight throttle changes. I run a 3:54 gear with 28" MT sportsman SR. I ran a 12:78 best of 2 passes. But I did discover that I did not have the settings correct for the Dual sync distributor and was 11 degrees short on total timing. Now that I have everything sorted and a little work on my part, I do believe it will turn low 12's high 11's and be able to drive the 40-50 miles each way to the track. I have had the car on the interstate and have no issues cruising with traffic at 70-80mph. Now that I have the kinks worked out I am very happy with the car, just some bumps and bruises along the way due to my own ignorance. I do think the system outside the bad ecu would have operated fine if I had the fuel system configured correctly for my application. I do also believe the MSD distributor along with the coil driver included with the Sniper system would have worked as advertised with the fuel system configured as it is now. Yes there were added expenses but I feel these were due to my own fault. Hope this helps you out.
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Aussiemopars
Well-Known Member
So you went from a dead head system to using the regulator on the Holley unit and a return line back to the tank? I was wondering about that. I'm running a dead head system and I'm getting a bit of a whistle through the throttle body when I start to mash the peddle, almost sounds like the injectors are losing pressure as you squeeze the throttle.
No I had dead headed off the external regulator to the TBI with the return port capped off on the TBI. I wasn't using the regulator built into the TBI at all. Just the external regulator. Now I pulled the guts out of the regulator built into the TBI and routed the return line from the TBI return to the external regulator then back to the tank so the injectors see full fuel flow and pressure all the time, (I have the external regulator set to 58 psi) like a modern car with the pressure regulator on the out put side of the fuel rail.
The whistle from what I have read on the Holley forums is not uncommon of an issue and some people have reported trimming or using different gaskets. I haven't noticed a whistle but with the 3" exhaust I don't hear too much but the engine rumble. If you are losing pressure at the injectors it will show as a lean condition on the AFR.
I've read thru these forums a bunch and they have helped some.
Sniper EFI
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Aussiemopars
Well-Known Member
Yeah those forums have been good. Thats how I found the issue with the TPS I had on the other thread.
Aussiemopars
Well-Known Member
I haven't had an issue with any lean conditions, just sounds funny when you go to accelerate. I'm thinking I'm going to pull up some day next to a rice mobile or another hot V8 and they're probably going to be thinking "what the hell is in that" then try and race me. It's reasonably loud and almost sounds like Turbo whistle.
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