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#1 |
Registered User
Join Date: Jan 2009
Location: colorado springs
Posts: 479
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Done with EFI, back to carb
Holley sniper EFI has been nothing but problems. Runs great when everything is working correctly but those times are few and far between.
I’ll be taking it out and I have a AVS2 650cfm on the way. Can’t wait to be done with this system. |
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#2 |
Registered User
![]() Join Date: Oct 2015
Location: Woodbridge Va
Posts: 401
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Re: Done with EFI, back to carb
That's unfortunate, lot of money to drop on something and it not pan out the way you hoped.
I plan on running one on my wife's 292, but we will see... |
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#3 |
Registered User
Join Date: Mar 2011
Location: MA
Posts: 354
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Re: Done with EFI, back to carb
Don't get rid of it yet!! They are great when dialed in but they take a while. Once dialed in you get aa whole different motor. What are the symptoms? I have taken a couple now that people have given up on and got them to where they should be. The biggest fault with them is EMI. It will wreck havoc with the system.
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#4 |
Registered User
Join Date: Jan 2017
Location: Larkspur, Colorado
Posts: 916
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Re: Done with EFI, back to carb
What is EMI ?? Steve weim55 Colorado |
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#5 |
Senior Member
![]() Join Date: Nov 2010
Location: Hays, KS
Posts: 2,490
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Re: Done with EFI, back to carb
Anytime I have a Holley on anything it goes away. PO switched the Quadra jet off my 402 and put a Holley on. I rebuilt the QJ and put it back on, runs much better. I’ve just never had luck long term with a Holley. Just my two cents
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#6 |
Registered User
Join Date: Jan 2009
Location: colorado springs
Posts: 479
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Re: Done with EFI, back to carb
Long list of issues, it was always something. I agree, when it’s not having problems, it runs great. To me, the juice isn’t worth the squeeze. I can tune a carb to get close to the same performance and it’s much easier to diagnose and fix carb with mechanical fuel pump issues. My old truck had 1406 with performer fuel pump, tuned it and never had a problem. With this EFI I was lucky to get a week out of it before I had to chase down another problem
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#7 | |
Registered User
![]() Join Date: Jul 2015
Location: 2nd left past the stump on a dirt road.
Posts: 2,629
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Re: Done with EFI, back to carb
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#8 |
Registered User
Join Date: Mar 2011
Location: MA
Posts: 354
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Re: Done with EFI, back to carb
ElectroMagnetic Interference.
If you're running an HEI it is really close the computer that it picks up EMI and runs interference. If you set parameters and then it changes from one time to another and nothings seems to be normal and different every time there is a good chance it's EMI. Shield the back of the Holley to separate it from the distributor and run it. Holley's biggest mistake is that all wiring should have been shielded. It's not any harder to tune than a carb. It's just a different way to tune. With this you need a good understanding of theory but it's the same thing as a carb. Running rich you turn a screw to lean it out. Running rich on Sniper you go in a change a parameter. Same theory but different way to go about it. Most people are better at tuning a carb because they can see what they are doing in a mechanical way. Using Sniper is more electrical troubleshooting that's new and most people can't grasp it. When we changed the instrument panels on airplane from old steam gauge to glass people had the same effect. But in the end troubleshooting was made way easier. |
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#9 | |
Registered User
Join Date: Feb 2003
Location: Santa Ana, CA
Posts: 2,191
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Re: Done with EFI, back to carb
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#10 | |
Registered User
Join Date: Jan 2017
Location: Larkspur, Colorado
Posts: 916
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Re: Done with EFI, back to carb
Quote:
Steve weim55 Colorado |
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#11 |
Registered User
Join Date: Jan 2009
Location: colorado springs
Posts: 479
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Re: Done with EFI, back to carb
Nothing to do with the altitude, the system is just real finicky . It was always something different. Spent more time chasing different problems then driving the truck.
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#12 |
Registered User
Join Date: Jan 2017
Location: Larkspur, Colorado
Posts: 916
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Re: Done with EFI, back to carb
I have yet to see a single person using an aftermarket EFI conversion that truly surpassed a carburetor on all fronts and was user installed. The two cases I know of that were successful, repeatable and reliable long term were both setup by a shop familiar with the kit and the shop equipment the execute it. (exhaust analyzer, dyno). Even then the performance is not without some minor issues.
I myself have never had my hands on one these conversions. After experiencing and reading of other peoples woes and concerns, I've come to the conclusion the only real way to achieve reliable, repeatable turn key EFI is to go with a complete OEM setup through engine swap. (ie: 5.3 LS or 5.7 TBI, etc.) That's the direction I'm going to go, it's more more work but I'm willing to do it to get the OEM performance I desire. Just my 2 cents of limited experience on the subject. I don't know if it would be a match for you but I could obtain info on the shop in Denver that did the the successful conversions. Good luck either direction you choose to go. Steve weim55 Colorado |
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#13 |
Registered User
Join Date: Oct 2016
Location: Dallas Texas
Posts: 3,090
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Re: Done with EFI, back to carb
.
The idea that shielding could solve the sniper's major issue(s) is very interesting and one you'd Holley would be keen to implement. I've got over 3000 miles on MSD Atomic, also w/billet dizzy. Only trouble was the IAC failed, 60 dollar parts store item. -klb
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67 C10 fleet fuel injected '70 402, 700r4, 3.73 posi 07 335 sport turbo 6sp 94 Trans Am GT LT1 6sp posi -- sold after 22yrs 99 540 sport V8 6sp -- sold 73 240z L24 4sp -- given to friend 68 C10 step 350/350 3.73 open -- sold |
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#14 |
Registered User
Join Date: Feb 2011
Location: Under the Truck Dreaming
Posts: 702
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Re: Done with EFI, back to carb
EFI in general needs to have the sensors grounded to the same place as the computer. I ran all of my grounds (from the sensors) back to the computer case and then grounded the case. It is extra wiring but keeps the system quiet from the EMI that liftlaw mentioned. I built my own wiring harness so it wasn't a big deal. Does the Holley kit do this? If the sensors are grounded to the block then they are "open" to interference (noise). Also as liftlaw mentioned HEI or powerful ignition could/should have the ignition wires shielded to quiet that source down also from EMI. But, yes, getting your head around a DIY EFI install can be a steep learning curve for sure, even from a kit.
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72 K20 Custom Camper, D60, 14BFF, full roller 406 TPI w custom built ECU and yes..it has tow hooks... |
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#15 |
Registered User
Join Date: Feb 2017
Location: Texas
Posts: 45
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Re: Done with EFI, back to carb
I tried an Edelbrock EZ Street EFI....nightmare ...could never get it to run right...finally bit the bullet and went with an LS swap
Last edited by Signkutter; 02-13-2019 at 06:07 PM. |
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#16 |
Registered User
Join Date: Feb 2011
Location: Under the Truck Dreaming
Posts: 702
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Re: Done with EFI, back to carb
It would be nice to have a separate EFI message board like other forums so we could capture this information and maybe even help each other out. Today's aftermarket EFI systems are pretty good software wise and I mean stable software. How they are tuned is another story and DYI installation adds a lot of variables like I mentioned in the previous post just about grounds. Good (great) grounding practices are your best friend. The few comments here about EFI kit failure is pretty disappointing from a tech support aspect. I would expect if you buy a kit there should be decent technicians on the other end of the phone to help out with your install questions and tuning/set up. Is this the case with the Holley and Edelbrock? Do they have decent tech support?
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72 K20 Custom Camper, D60, 14BFF, full roller 406 TPI w custom built ECU and yes..it has tow hooks... |
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#17 | |
Registered User
Join Date: Jan 2009
Location: colorado springs
Posts: 479
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Re: Done with EFI, back to carb
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#18 |
Who Changed This?
![]() Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,397
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Re: Done with EFI, back to carb
I worked for years in the electromagnetic engineering end of things. You wouldn't believe where EMI will go and how it will get there. That stuff is like roaches, it gets into everything. I don't know about Holley's engineering, but EMI is a tough nut to crack. I'd expect them to be electronics guys meeting with mechanical guys, with some software guys thrown in. You can't just put a piece of foil between the distributor and the rest of the system. Some people have alluded to making certain that all the grounds go back to the system, and not depend on "chassis ground". That's a major step in the right direction. On spacecraft, every system that has a power feed to it has its own ground back to the battery. Stray currents everywhere cause major havoc, otherwise.
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~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA |
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#19 | |
Registered User
Join Date: Mar 2011
Location: MA
Posts: 354
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Re: Done with EFI, back to carb
Quote:
Also must shout out to Holley tech support for their help. Great guys to deal with. They know about the EMI but not sure why they do anything about it. My suggestion would be to keep it on their and either figure it out yourself or bring it to someone who knows them. I can tune a carb pretty damn good but these things take it to a whole new level. I did a 67 Firebird that has a mildly built 455 and would break the tires loose in 3rd gear after. I’d offer to play around with it for nothing if I could. It’s worth it in the end. |
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#20 | |
Registered User
Join Date: Jan 2009
Location: colorado springs
Posts: 479
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Re: Done with EFI, back to carb
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#21 |
Registered User
Join Date: Feb 2007
Location: Cali Central Coast
Posts: 5,191
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Re: Done with EFI, back to carb
I had a guy that works on street rods and had done a couple of them put my FItech EFI in, and I had real problems for the first month. I had an electric fuel pump mounted to the frame, and it wasn't working. We ended up putting one in the tank, and it runs great, really feel it is stronger with the EFI than it was with the carb. First start up it cranks a bit, but after that it kicks right over, great response, and it's got a little computer that I can tune it with if I want. Once you get it right, they are really nice.
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'67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD ![]() Click here to support the board Philippians 4: 6-7 |
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#22 |
Senior Member
![]() Join Date: May 2006
Location: Philadelphia, Pa. 19454
Posts: 9,505
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Re: Done with EFI, back to carb
That would help, if we could get a EFI forum on our boards, or at least a link to other sources for info.
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Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim |
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#23 |
Moderator
![]() Join Date: Jun 2017
Location: Cherryville, NC
Posts: 2,193
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Re: Done with EFI, back to carb
The "Electrical" sub forum lists EFI swaps as a component thats permitted to be posted.....perhaps a sub forum listed under Electrical would be the easiest to deploy....
BTW...best practice is to always run dedicated ground feeds back to ground bus.... When I built my shop...I ran all power feeds thru EMT plus dedicated ground return wires back to the panel, along with grounding the EMT to the panel....makes certain the circuits work correctly...
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#24 |
Registered User
Join Date: Feb 2011
Location: Under the Truck Dreaming
Posts: 702
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Re: Done with EFI, back to carb
Yes X2 a separate sub forum would be great, maybe a Mod will see this and agree (or not).
__________________
72 K20 Custom Camper, D60, 14BFF, full roller 406 TPI w custom built ECU and yes..it has tow hooks... |
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#25 | |
Registered User
Join Date: Mar 2011
Location: MA
Posts: 354
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Re: Done with EFI, back to carb
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