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Holley Sniper EFI and RobbMC Surge Tank, 351c and FMX


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Here are a couple pics of what it looked like.

IMG_2356.jpg

 

IMG_2357.jpg

 

Was this an option back in the day or was it standard on all 72 models? When I bought the car it already had an aftermarket carb on it, so if it was an option I don't know if I have it. I will search around near the firewall to see if I can find the wire that went to this regardless, thanks!

 

SUCCESS!! After tons of messing around under the dash and touching every connection possible with a test light and multimeter, finally found this right in the perfect spot behind the throttle body. 12v ignition, not being used.  :D 

 

IMG_6822.jpg

 

IMG_6826.jpg

 

Not sure if this is what 73pony was referring to, but regardless thank you for your help! 

 

Hopefully in the morning after wiring both the Sniper EFI and the PowerSurge to it, I'll be able to start her!

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Hard to see the connector, Is it not the one ment for the airco compressor? Its on when ignition key's on and stays on during kranking? If true this might become my guy too!

73 modified Grande 351C. Almost done. 

71 429CJ. In progress

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In side news of the install... Before ordering the kit, I was in contact with Holley techs and they provided me a pdf about the product and content of the kit.

One of them, as I wrote in a previous reply, was that the fuel lines supposed to cover feed and return lines said 40ft in this doc, were in fact 20ft on delivery.

 

Being an old monkey and because of the extra costs involved for us people of the other side of the pool. I've mailed them

asking for nothing, just to let them know that for a kit that cost us 1/3 more than US customers. It would not have made any difference

pay a few buxx more and be sure to have plenty length to make a secure install, with no worries about coming short.

 

Just got a reply from Holley: Looks like they do care about old monkeys. The missing 20ft line is about to take off and should land here in a few days, free of charges.

As I can work on the car only weekends and I'll prolly need that return line by next weekend. It might just be on time.

I was going to buy it locally and I will if its not here on time.

 

But from this Holley's reply, all I can say is: thumbs up!

73 modified Grande 351C. Almost done. 

71 429CJ. In progress

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Hard to see the connector, Is it not the one ment for the airco compressor? Its on when ignition key's on and stays on during kranking? If true this might become my guy too!

 

When emission modifications were made in the early '70s engines developed a tendency to continue to try to run after the key was turned off and was referred to as dieseling (no ignition, just fuel being drawn in through the carburetor). To try to stop this a throttle position solenoid was added to the carburetors that set the throttle plate idle position as soon as the key was turned on. When the key was turned off the throttle plates returned to the completely closed position so the engine couldn't run. For most of our cars this happened in 1972, although some 6 cylinder cars, with automatics, received it in 1971. My '71 M code did not have it, so I had to run a separate wire for the electric choke.

 

 

“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein

 

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SHE RUNS!!!

 

Took a while to get her going at the beginning because I forgot to set the idle screw back to normal after messing around with it  :shootself:   But all good now the car starts right up every time, just let it do some self learning. It's a pretty hot day and the car idling in the garage is getting up to 190 degrees so I shut her off for the time being while I research the other parameters.

 

Currently it's at around 13.5 AFR is this a decent number?

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That's great news. You must feel like turning cartwheels on the lawn.

 

13.5 sounds reasonable to me. Does your instruction manual say what to expect?

 

 

“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein

 

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That's great news. You must feel like turning cartwheels on the lawn.

 

13.5 sounds reasonable to me. Does your instruction manual say what to expect?

 

Yes I am very happy to say the least. Manual says it should be anywhere from 13.5-15 at idle, but may need to be richer than that for a bigger cam. This is my cam: https://www.summitracing.com/int/parts/cca-32-421-8/overview/ not sure what it's considered as in the grand scheme of things so I pressed the mild/stock cam category instead of the Street/Strip or Race categories (hopefully that was a good choice). It's a really hot day here in Vancouver though about 82F or 28 celsius, so when stopped at idle the car heats up pretty fast. While cruising shes around 86 F. Time for electric fans and an alum radiator next!!

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SHE RUNS!!!

Yeeeeeha!

Dam I wish I could continue work on this install right now! Wife's todos during Sniper installs should be forbidden by law...

 

@Don C

Mine came with it, I recall dump the charcoal cannister, the old carb with that thing on it and most 2v specifics stuffs.. (was 18 at the time, something I would no longer do). So I should have that connector and it might still be hot... unless its one of the circuits I've shutdown/removed when I've done the dashboard.

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73 modified Grande 351C. Almost done. 

71 429CJ. In progress

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For some amazing reasons, wife's todo went "poof"

Guess what I did instead :)

 

More wiring, while at it renewed vaccum hoses, secured and sorted the mess of wires behind engine. Haven't found that connector.

So studied the ignition switch circuit in good old Haynes book, and so went the last unit wire for the engine baye to its place.

 

As I forgot buy an aluminum plate to make the kickdown bracket, I went back to the hood/ram air closing issue.

No matter how the sniper works, I can't drive with an open hood.

 

cut.jpg

Measured all again, so the extra height of the unit plus the spacer would match the arc of the hood while closing.

As there's no way back but redo an entire new one, took my time and the diff was out. Repainted the exposed polymer at the cut.

 

paintandback.jpg

Then after some massage it got its shine back, cleanup both unit and in ram-air high flow filters and re-oiled them.

 

fits.jpg

and voila! Fits perfect and hood closes tight on it.

 

Tomorrow I'll remove the front fender to see if there's a safer route than via trans tunnel and not too visible for the fuel lines...

73 modified Grande 351C. Almost done. 

71 429CJ. In progress

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For some amazing reasons, wife's todo went "poof"

Guess what I did instead :)

 

More wiring, while at it renewed vaccum hoses, secured and sorted the mess of wires behind engine. Haven't found that connector.

So studied the ignition switch circuit in good old Haynes book, and so went the last unit wire for the engine baye to its place.

 

As I forgot buy an aluminum plate to make the kickdown bracket, I went back to the hood/ram air closing issue.

No matter how the sniper works, I can't drive with an open hood.

 

cut.jpg

Measured all again, so the extra height of the unit plus the spacer would match the arc of the hood while closing.

As there's no way back but redo an entire new one, took my time and the diff was out. Repainted the exposed polymer at the cut.

 

paintandback.jpg

Then after some massage it got its shine back, cleanup both unit and in ram-air high flow filters and re-oiled them.

 

fits.jpg

and voila! Fits perfect and hood closes tight on it.

 

Tomorrow I'll remove the front fender to see if there's a safer route than via trans tunnel and not too visible for the fuel lines...

 

Happy to see you got it to fit Fabrice!!

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So after a couple hours now of driving the car the sniper seems to be doing pretty well. Initially right after startup the car was shooting up to 1100 or so rpm, but then after 2 seconds or so would drop down to the 800rpm range. Additionally, even though I set my idle to hover around 680rpm it was constantly 750-850 range. That's when I came across these two helpful links:

 

http://www.efisystempro.com/efi-pro-hangout/holley-sniper-installation-startup-troubleshooting

 

https://forums.holley.com/showthread.php?19723-Sniper-EFI-tuning-questions-amp-suggestions

 

I did what the first link recommended (adjusting the idle speed curve in advanced settings) and now my idle seems pretty consistent at where I want it right around 680  ::thumb::

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Hi guys so today I realized that my ground wire going to the PS is getting extremely hot. Both my power and ground wires are 10 gauge, and I have them both hooked up to the POS and NEG side of the starter solenoid. I have several things grounding off of the solenoid will that cause a problem? I'm new to wiring so am unsure of what could be wrong. 

 

Another thing that I suspect however is the difference in sizes for the Power wire as it goes to the relay and the fuse. Currently I have the Power Wire (10 gauge) attached to the solenoid, which then goes to a smaller gauge wire that came on the inline 15 amp fuse, then it goes to the fuse itself, then on the other side of the fuse is the same smaller wire it came with, which then goes to the relay wire which is the same size as the fuse wire, then out of the relay comes some more of the smaller gauge, then it goes back to 10 gauge to the PowerSurge. 

 

Sorry if that was confusing. So the question is are mismatching power wire sizes something that would cause a ground to heat up even if the ground wire is the same size or bigger than all the power wire connections? The power wire isn't hot at all if thats relevant..

 

Thanks,

 

Adam

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Awesome Adam, wish I was there :)

Never got it on the carb to idle that low, 800+ yes, bellow would have ment for me be shaken crazy and have

to keep it on pedal for minutes during winter before it could keep it without dying. Curious to hear the steady "blom blo blom blom"...

 

Regarding higher rmp's in first seconds, My 5.0 t-bird does that too, it goes 1100, then goes gradually back to +-800.

 

On my side, far from hearing the sweet low rpm sound, went bits further, installed the monitor inside, and routed it.

I was yesterday worried about being to short on wire length, but turned out be spot on.

 

Today showed me, that every new step in this install adds up to the todo...

I wasn't convinced at all about the safety of installing the two fuel lines via the tunnel already crowded by a shit load of wires.

Going bits left or right, the lines would comes too near of the exhaust heat... Plus I already know that if i would go this way,

as I plan an AOD swap, that these might be in my way soon or later and make me regret I've installed them this way.

On my 93 tbird its also coming form the side, so I've removed the front panel to see and pick the shortest and safest way.

 

Of course after I started remove the old line and tried pick the "ideal" location, the todo grown on me, as I need relocate

previous wirings, like my extra electric fan to clear up some space... todo++

 

inbay.jpg

The location should also allow me to secure them bellow the reinforcement bar (or whatever these massives brackets are named)

 

holes.jpg

but then comes another prob in sight. Even with a nice fat grommet, once on the wheel side, they need follow some serious

curves and I really not sure I can do this with the fuels lines in one go. (I mean I could, but not sure thats the way at all)

I think 90 degrees connections would be better here.. and also may be at the bottom, where the original line takes a 90 degree turn to be aligned to the floor.

From there its straight line to rear of the car, and I haven't seen (yet) a place where it would become a problem

 

I even wonder if two metal lines bigger but identical in shape to the original would not even be better...

 

Any suggestions about eventual hardware I should use here?

73 modified Grande 351C. Almost done. 

71 429CJ. In progress

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oh I see my reply came 1 min too late...

 

Is the use of the starter solenoid indicated for this install? Could you share the diagram?

 

oh and don't read this one unless you want to leave the car in garage bits longer like me and end up recheck all connections you found :)

http://www.mustangandfords.com/how-to/interior-electrical/1511-dont-do-it-top-12-wiring-mistakes/

73 modified Grande 351C. Almost done. 

71 429CJ. In progress

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oh I see my reply came 1 min too late...

 

Is the use of the starter solenoid indicated for this install? Could you share the diagram?

 

oh and don't read this one unless you want to leave the car in garage bits longer like me and end up recheck all connections you found :)

http://www.mustangandfords.com/how-to/interior-electrical/1511-dont-do-it-top-12-wiring-mistakes/

 

No the use of the solenoid is not indicated, but it seemed like a good place for me to ground / get power form for the Surge Tank. Thanks for the link, I took a look at it seems like I have done everything correctly, (the PS has a dedicated power line, ground, relay and fuse), but I will try switching the ground location now to see if that helps!

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Awesome Adam, wish I was there :)

Never got it on the carb to idle that low, 800+ yes, bellow would have ment for me be shaken crazy and have

to keep it on pedal for minutes during winter before it could keep it without dying. Curious to hear the steady "blom blo blom blom"...

 

Regarding higher rmp's in first seconds, My 5.0 t-bird does that too, it goes 1100, then goes gradually back to +-800.

 

On my side, far from hearing the sweet low rpm sound, went bits further, installed the monitor inside, and routed it.

I was yesterday worried about being to short on wire length, but turned out be spot on.

 

Today showed me, that every new step in this install adds up to the todo...

I wasn't convinced at all about the safety of installing the two fuel lines via the tunnel already crowded by a shit load of wires.

Going bits left or right, the lines would comes too near of the exhaust heat... Plus I already know that if i would go this way,

as I plan an AOD swap, that these might be in my way soon or later and make me regret I've installed them this way.

On my 93 tbird its also coming form the side, so I've removed the front panel to see and pick the shortest and safest way.

 

Of course after I started remove the old line and tried pick the "ideal" location, the todo grown on me, as I need relocate

previous wirings, like my extra electric fan to clear up some space...  todo++

 

inbay.jpg

The location should also allow me to secure them bellow the reinforcement bar (or whatever these massives brackets are named)

 

holes.jpg

but then comes another prob in sight. Even with a nice fat grommet, once on the wheel side, they need follow some serious

curves and I really not sure I can do this with the fuels lines in one go. (I mean I could, but not sure thats the way at all)

I think 90 degrees connections would be better here.. and also may be at the bottom, where the original line takes a 90 degree turn to be aligned to the floor.

From there its straight line to rear of the car, and I haven't seen (yet) a place where it would become a problem

 

I even wonder if two metal lines bigger but identical in shape to the original would not even be better...

 

Any suggestions about eventual hardware I should use here?

 

Went through the exact same experience with my carb this winter holding the pedal down to keep the car alive, glad I don't have to do that anymore! I do love the low rpm sound, nothing beats a grumbly american V8! 

 

Your plan for the gas line route looks pretty good! Not sure what kinds of hardware you should be using, hopefully another member with some more experience can point you in the right direction. Got my fingers crossed that you'll get her on the road soon!

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Hi guys so today I realized that my ground wire going to the PS is getting extremely hot. Both my power and ground wires are 10 gauge, and I have them both hooked up to the POS and NEG side of the starter solenoid. I have several things grounding off of the solenoid will that cause a problem? I'm new to wiring so am unsure of what could be wrong. 

 

There is no positive or negative side of the starter solenoid.  There is a battery side and a starter side, however. 

 

All the solenoid does is act as a relay.

Let me check your shorts!

http://midlifeharness.com

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Hi guys so today I realized that my ground wire going to the PS is getting extremely hot. Both my power and ground wires are 10 gauge, and I have them both hooked up to the POS and NEG side of the starter solenoid. I have several things grounding off of the solenoid will that cause a problem? I'm new to wiring so am unsure of what could be wrong. 

 

There is no positive or negative side of the starter solenoid.  There is a battery side and a starter side, however. 

 

All the solenoid does is act as a relay.

 

Well that's embarrassing...  :shootself:  Switched the ground and now she works perfect... Haha.... Kill me now. Thanks midlife

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So its my 3rd day driving the sniper and after some spirited driving an old problem of mine occurred... dieseling. I didn't know what to call it before 73pony referenced it, but previously I just thought it was the old carb's fault. Now that it happened with the new sniper, I'm wondering how I can fix it? Any suggestions would be great!

 

Note: it only does this when I don't use 94 octane, but with a 9:5:1 compression I didn't think I would need 94 octane..? A couple of people I spoke in person with suspected that the 94 octane here in Vancouver has 0 ethanol while the others do. Another suspects some type of additive in the 94 is making the fuel less prone to explosion when hot, therefore not exploding after the sparks cut or "dieseling"

 

-EDIT-

 

Just tried stomping on the gas from a stop and the car backfired through the Throttle body and died... I

thought this issue would be gone when I swapped out the carb as I thought that was a symptom of a bad accelerator pump, but I guess I was wrong. Can't hear any pinging (at one point I did, but retarded the timing just enough so I couldn't hear it anymore), but even without the pinging aren't dieseling and backfires a sign of the timing being too far advanced?

 

Thanks in advance,

 

Adam

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Octane level is most important, in fact that the very definition of it. How it resists to compression to self ignition.

Over here we have only 95 and 98 and never got that issue on 95. I've got some pinging during accelerations running on 95 depending on brands, but never got engine run-on on shutdown.

Going lower octane will increase chances it occurs.

On mine, I've set double electrodes platinums plugs and the pingings were practically gone.

 

I know you have more friends running similar V8's combos, so if this is not a common issue for those running lower than 94 octane, I'd first loose the plugs and inspect them carefully.

If of wrong grade, they may become too hot. They would look glazed. if they look to white, its mixture that is too lean.

if they look fine, i'd go for an air leak test (intake to heads). Using some paste, oil around intake to close potential source of air succion.

Then I'd look at the timing.

73 modified Grande 351C. Almost done. 

71 429CJ. In progress

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Dieseling requires a fuel source. It should not be possible to have dieseling with fuel injection. As soon as the ignition switch is shut off the injectors remain closed, eliminating the fuel source that causes dieseling with carburetors.

 

Two possibilities that I can think of, one, debris in the injectors preventing them from closing and continuing to drip fuel until the pressure in the system bleeds off. Two, the crankcase is saturated with fuel and the fuel vapors are drawn through the PCV.

 

Make that 3, because the injectors are inside the throttle body, if they or the fuel connections are loose, the fuel could come from them, also.

 

 

“If you can't explain it simply, you don't understand it well enough.”

--Albert Einstein

 

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What is the car idling at? Higher idle is usually a sign that the throttle plate is not set up properly or you have a faulty IAC motor. You will have residual fuel in the plenum and if the IAC motor is allowing sufficient air in you could have dieseling if the fuel octane is too low. The idle solenoids in the carb systems were used to close the throttle plates to avoid dieseling by choking the air flow similar to a IAC motor in TBI systems.

-john

(jbojo)

351C 4V cc heads, 10.5 : 1 CR, 290 Herbert cam, Flat top forged pistons, forged connecting rods, Atomic efi,

C6 with Gear Vendor overdrive, 3.89 Tru Trac, Hooker Super Comp with 2 1/2" Pypes Exhaust.        

 

Some Mod pictures can be seen at: [button=http://www.7173mustangs.com/forum-garage?filterxt_uid=2026]Bojo's Garage[/button]

 

 

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From video's I saw on his channel, he runs a spacer looking like if made of flexible plastic.

I've seen on mine (aluminum one) that the upper gasket was distorted following the surface of the carb plate. So same "print" could occur on this spacer

and create a small air leak if he kept this one to receive the new unit. That's what made me think of air leak before timing issue.

but yeah, I have zero experience with low octane fuel. So that might simply be it.

 

Out of curiosity, what are the octane levels you guys can buy in regular stations?

73 modified Grande 351C. Almost done. 

71 429CJ. In progress

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Dieseling requires a fuel source. It should not be possible to have dieseling with fuel injection. As soon as the ignition switch is shut off the injectors remain closed, eliminating the fuel source that causes dieseling with carburetors.

 

Two possibilities that I can think of, one, debris in the injectors preventing them from closing and continuing to drip fuel until the pressure in the system bleeds off. Two, the crankcase is saturated with fuel and the fuel vapors are drawn through the PCV.

 

Make that 3, because the injectors are inside the throttle body, if they or the fuel connections are loose, the fuel could come from them, also.

 

Hmm.. Given that the EFI is brand new and the previous carb also did the same thing, I'd like to think it's not debris in the injector especially with the 10 micron fuel filter. How can I tell if the crankcase is saturated? My PCV is not currently hooked up.

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What is the car idling at?  Higher idle is usually a sign that the throttle plate is not set up properly or you have a faulty IAC motor.  You will have residual fuel in the plenum and if the IAC motor is allowing sufficient air in you could have dieseling if the fuel octane is too low.  The idle solenoids in the carb systems were used to close the throttle plates to avoid dieseling by choking the air flow similar to a IAC motor in TBI systems.

 

I have the idle fluctuating from around 680-800 when in drive. Should I have to run 94 octane for an engine with a supposed 9:5:1 compression ratio? (as a note that's the compression ratio I was told by the guy who spec'd out my engine. I have 2v aussie closed wedged chamber heads, dished pistons and a mild cam) Also any input on the backfire and stall when I floor it from a stop? Thanks

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