desmocruiser
SILVER Star
Holley Sniper 2GC to 2F Install using Mosley Motors adapter (9 Viewers)
- Thread starter KY Longhunter
- Start date
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desmocruiser
SILVER Star
Yeah I checked everything, replaced a couple of vacuum caps and resealed the base to make certain. I may run a new vacuum line between the advance and front of throttle body to make sure there isn’t a hairline crack I couldn’t see, feel, or get carb cleaner into.
you’ve taken the brake booster off line? Double checked the wiring coming off of coil like Cam suggested?
desmocruiser
SILVER Star
Double checked the wiring, haven’t opened the cap, rerun vacuum hose from the advance or disconnected vacuum from the brake booster, next on the list.
Also- i’d let her come up past the 160* before making any adjustments.
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MOTOV8R
SILVER Star
@desmocruiser did you follow up on this? I would also check the power lead to the DUI, several folks run the DUI power via relay to make sure it gets what it needs.
@Coolerman even sells a specific sub harness if you need one.
desmocruiser
SILVER Star
I inspected to the best of my abilities, admittedly not very familiar, but looked good to my untrained eyes. Wiring seems simple, just one from the alternator and it is getting power, I assume since it ran power is moving to the ignition?….
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One more suggestion to add to my one from above that doesn't cost money. Take the air cleaner assembly off and look down the throttle body with it running (and revving) to make sure that the fuel mist looks even on both sides. It should be apparent if one isn't functioning correctly. It'll look like one is putting out twice as much fuel and the spray pattern won't look refined. And while you're there, watch the fuel pressure gauge while revving it. A lot of times the fuel pressure will be steady at idle but will drop under throttle. (you might have already done this, and I missed it) If you dive far enough in to check the fuel injectors, put a zip tie around where the connector mates to the injector to hold the two snug together. Sounds hokey, but it has been discussed a million times on the Holley forum, and this seems to be the preferred method of remedy. If it ran fine before, it's something fairly simple I'd bet.
desmocruiser
SILVER Star
I thought it looked correct in the throttle bodies. Here is a poor quality video of starting/running.
desmocruiser
SILVER Star
I have checked and readjusted the timing a couple of times and it’s at the same setting the truck had always ran well, that was one of my initial thoughts. The rough running really doesn’t go away at any timing point.
I am at a spot where I am beginning to consider other internal issues with the valve train etc., just don’t want to jump to that conclusion until the experienced Sniper members confirm that everything with the Sniper operation is within proper parameters.
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What is your timing set to?
As everything in life we all have an area of expertise in something …rest assured engine mechanics is not mine. Something in the last 50 years has helped me survive my lack of knowledge. It sounds like you have run through the gamut of circumstances other than an actual issue in the ECU of the sniper, but it sounds to me like you may be having ignition troubles. I had a performance distributors DUI On my FJ40 for the Weber carburetor that was on it.
I had a few minor issues with it being a little sluggish and started to dig into why the timing could be an issue or a distributor malfunction either mechanically or electronically. I can’t steer you in any of these directions but timing is a critical function for proper combustion. Is your timing set properly With the bead in the flywheel and have you had the engine running while rotating the distributor to see the bead follow towards the left or to the right of the pointer. And then make note of the changes that you will hear?
When I changed the DUI distributor to the Holley hyper Spark system, I noticed a big change in the hesitations and response. However, it was likely that my DUI was never set properly.
I had a few minor issues with it being a little sluggish and started to dig into why the timing could be an issue or a distributor malfunction either mechanically or electronically. I can’t steer you in any of these directions but timing is a critical function for proper combustion. Is your timing set properly With the bead in the flywheel and have you had the engine running while rotating the distributor to see the bead follow towards the left or to the right of the pointer. And then make note of the changes that you will hear?
When I changed the DUI distributor to the Holley hyper Spark system, I noticed a big change in the hesitations and response. However, it was likely that my DUI was never set properly.
So I’m going to be converting over to a sniper sometime in the near future. Have majority of the items to make the move but waiting to get the sniper itself after I add the other goodie’s first.
I just started my cruiser for the first time in a few years and it sounded pretty good. The motor was rebuilt several years ago but have been working on the 40 within those years.
What recommendations do you guys suggest to make sure everything is in working order before switching over?
I just started my cruiser for the first time in a few years and it sounded pretty good. The motor was rebuilt several years ago but have been working on the 40 within those years.
What recommendations do you guys suggest to make sure everything is in working order before switching over?
desmocruiser
SILVER Star
It should be around 12, I traditionally have gotten it there and fine tuned to eliminate detonation and smooth power.
Thanks again for all the help!
Good compression is one… clean electrics is more important than you’d believe. Check your vacuum and guard against vacuum leaks around the intake manifold.
Doesn't Sniper react to an intake vacuum leak (i.e., increased MAP) by increasing fuel, resulting in higher idle RPMs?
This is not an ignition issue.
Have you checked the plugs? Any chance they got fouled?
The numbers look right on the screen. The MAP is not hopping around too crazy like a vacuum leak would cause.
I really don't think you have ECU problems. It would not run that good.
Stumped along with you.
Have you checked the plugs? Any chance they got fouled?
The numbers look right on the screen. The MAP is not hopping around too crazy like a vacuum leak would cause.
I really don't think you have ECU problems. It would not run that good.
Stumped along with you.
desmocruiser
SILVER Star
Yes, Along with checking the timing, vacuum caps and lines, I put in new spark plugs, and a new O2 sensor. With the help of the forum I have been able to go a few steps further and rule out a few more things.
If the ECU is good, could a bad HEI Coil cause that miss?
Is a valve spring, rocker, or something else in the top end a possibility?
