Holley Sniper Trouble (1 Viewer)

[SSICKLE1]

I've been working with Holley or should I say I've been communicating with Holley for several months off and on. I'm getting nowhere so I thought I would try here.

Im put a sniper 2300 on my 1985 FJ60 just about a year ago. I spent a lot of time looking at the threads on this sight before buying and installing. The sniper worked OK for a while other than a dead spot at WOT, it's an FJ60 with a 2f so WOT isn't really a thing so I lived with it. down the road had to change an O2 sensor due to an exhaust leak.

I now have a real problem. Truck starts and runs fine through the idle circuit and sometimes run fine through the entire range. But, at some point I go to a very lean condition under load, say above the idle circuit, ie, excelleration, going up hill. The lean condition is >35AFR so it's more than a stumble. At this point I wish I left the carb on in every way.

I have a fuel pressure gauge at the unit, it's right around 58. The injectors are working here's a video

Per Holley, we have changes regulators, changed the filter, checked the pump for signs of being hot during episodes. I have logged the incident and sent it to them. They are stating the obvious, it's not getting fuel.

For my part It's installed correctly close to and below the fuel tank on the frame rails with a corvette type regulator, bottom fuel line feed top fuel line return.

Holley wants me to get a fuel pressure gauge inside my vehicle which is either very expensive or not safe/recommended. They also want me to drop the tank, they think the return is oxygenating the fuel and thereby creating this event.

I think this product is defective, and so we're in a pissing match.

If you are familiar with this product love to hear some other ideas because I'm getting close to junking this thing even though I'm over $2k into it right now.

Thanks. Here's some pictures of the filters pump exc.

 

[britbike2001]

I put the same Sniper in one of my FJ60's and have been very happy with it. Seat of the pants dyno showed noticeable horsepower gains and improvements when making large elevation changes.

The WOT stumble and bogging happened to me, though my AFR was too rich. I changed the fueling curve and resolved the issue that way.

If you are not getting any fuel, I'd look at the pump and filter mounting. Being on its side you can get a big gas bubble on top and at high fuel flows you could be pumping some gas instead of liquid fuel which would cause issues. I'd try mounting the pump and filter so they are vertical thus self venting.

Not wanting to put a pump in my tank, I opted for an Edelbrock Universal Fuel Pump 36032 which retains the mechanical pump to fill a chamber and the high pressure pump draws from it. I mounted that in my engine bay with all the fuel lines and filters having a slightly upward pitch so there are no gas pockets.

It has worked just fine and even survived a three hour drive, while towing, with diminishing power, due to undiagnosed rotten wire inside the fusible link. I got home with only 9.2V in the system. The Holley was not happy but worked enough to get me home and the fuel pump got really, really hot but carried on as well.

I know how much work it takes to put the Sniper in and tune it, so I appreciate your desire to not undo all that effort.

 

[Skreddy]

What is you idle AFR and MAP? That looks like it’s spraying a ton of fuel at idle which would lead me to think maybe it’s trying to compensate for a big vacuum leak?
My sniper sprayed fuel like that at idle to compensate for a vacuum leak: from the factory, the boost plug was left out. It was sent to Holley twice and they said it tested fine. I saw the missing plug by chance. I had a very high MAP when it should’ve been; like 75 kPa at idle where I was expecting closer to 35 ish.

Maybe not your issue but worth a look?

 

[SSICKLE1]

What is you idle AFR and MAP? That looks like it’s spraying a ton of fuel at idle which would lead me to think maybe it’s trying to compensate for a big vacuum leak?
My sniper sprayed fuel like that at idle to compensate for a vacuum leak: from the factory, the boost plug was left out. It was sent to Holley twice and they said it tested fine. I saw the missing plug by chance. I had a very high MAP when it should’ve been; like 75 kPa at idle where I was expecting closer to 35 ish.

Maybe not your issue but worth a look?

Seems like it is spraying too much to me as well so I should look into that. My main problem is it not spraying enough under load and with the butterflies opened past the idle circuit.

My rig is and 85 fj60 and it is desmogged. I'll put a vacuum gauge on it and see what it reads. Just out of curiosity where does one read manifold vacuum on an fj60?

 

[SSICKLE1]

Seems like it is spraying too much to me as well so I should look into that. My main problem is it not spraying enough under load and with the butterflies opened past the idle circuit.

My rig is and 85 fj60 and it is desmogged. I'll put a vacuum gauge on it and see what it reads. Just out of curiosity where does one read manifold vacuum on an fj60?

its making 19 on the vacuum gauge. Looks like two sources of manifold vacuum are attached to each other. Seems like they should have just capped it all. Anyhow, the vacuum seems fine, doesn't look like there are any leaks...amazingly.

 

[SSICKLE1]

Seems like it is spraying too much to me as well so I should look into that. My main problem is it not spraying enough under load and with the butterflies opened past the idle circuit.

My rig is and 85 fj60 and it is desmogged. I'll put a vacuum gauge on it and see what it reads. Just out of curiosity where does one read manifold vacuum on an fj60?

further prompted by your question I pulled a plug and it's fouled, chances are the O2 sensor is fouled as well. If that's the case one or both of the collectors for my headers must be leaking. Funny thing is there are no signs of an exhaust leak. There's no backfiring using the engine as a break down hill none of that...except I have fouled plugs so it's giving me too much fuel.

 

[WildernessRimFab]

If your AFR is reading at >35AFR your 02 sensor is either dirty or nuked.
I have a sniper on my 40 and it goes through 02 sensors. I installed a heat sink spacer and that semi-helped.

Id bet that if you take out the O2 sensor its covered in carbon.
It will be covered in carbon because the O2 sensor is reading ultra lean so it will add tons of fuel to compensate.
The massive stumble that you get is actually rich, not lean.

Put it in a vise and heat the end up cherry red with a blowtorch and the carbon will be gone.
Reinstall in the truck and all will be well.
I have to do this about once every 14-16 months.

 

[SSICKLE1]

If your AFR is reading at >35AFR your 02 sensor is either dirty or nuked.
I have a sniper on my 40 and it goes through 02 sensors. I installed a heat sink spacer and that semi-helped.

Id bet that if you take out the O2 sensor its covered in carbon.
It will be covered in carbon because the O2 sensor is reading ultra lean so it will add tons of fuel to compensate.
The massive stumble that you get is actually rich, not lean.

Put it in a vise and heat the end up cherry red with a blowtorch and the carbon will be gone.
Reinstall in the truck and all will be well.
I have to do this about once every 14-16 months.

You are spot on. The fuel sputtering above the sniper at idle should have been my first giveaway. Now I need to try and find where the exhaust leak is.

I was wondering if I could clean the O2 sensors, thanks for that.

 

[Rustyj41]

I smoke an O2 sensor about once a year. I’ll notice my AFR jump to 15-17 and hesitation at 2700 RPM. New sensor all is well.

I do have an intake pump and I had to reroute the return outside of the dish in the take as it was creating bubbles and allowing air into the system.

At that time I switched to a DW200 fuel pump. It’s wicked silent. I also swapped to the corvette style fuel regulator and filter.

I still need to finish adding my hyperspark CEI and distributor. Once that is finish I will have successfully deleted all vacuum lines.

 

[klinetime574]

I think your pump is too far away from your tank. I have mine much closer and have not had the issues you describe. Old picture from my initial install back in 2021.

Also how is your oxygen sensor placed?

 

[Skreddy]

its making 19 on the vacuum gauge. Looks like two sources of manifold vacuum are attached to each other. Seems like they should have just capped it all. Anyhow, the vacuum seems fine, doesn't look like there are any leaks...amazingly.

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What’s the handheld saying for MAP? I was still seeing good vacuum readings off my manifold with the missing plug.
Looking at that last pic, that hose looks toast. I wouldn’t be surprised if you had vacuum leaks even with a good vac reading.

Also curious how your O2 sensor is mounted. I’ve put 5-6000 miles on the sniper in my 40 and I’ve never had an O2 sensor problem. For guys that this is happening to, are you still in learning mode all the time? What’s your idle speed and target afr’s?

 

[SSICKLE1]

What’s the handheld saying for MAP? I was still seeing good vacuum readings off my manifold with the missing plug.
Looking at that last pic, that hose looks toast. I wouldn’t be surprised if you had vacuum leaks even with a good vac reading.

Also curious how your O2 sensor is mounted. I’ve put 5-6000 miles on the sniper in my 40 and I’ve never had an O2 sensor problem. For guys that this is happening to, are you still in learning mode all the time? What’s your idle speed and target afr’s?

MAP bouncing 29 to 30. O2 sensor behind the collector where header goes to tailpipe. It's as far tilted up I can can get it without removing the exhaust. Agree on the vacuum hoses. Most can be plugged off really only need vacuum to the booster and the Dizzy.

 

[Skreddy]

MAP sounds good then. I wonder if the distance headers add make much difference. I’m running a stock manifold and mounted about 6” below the collector on the vertical downpipe. Finding any exhaust leaks like you mentioned is a good start. Good luck!

 

[SSICKLE1]

MAP sounds good then. I wonder if the distance headers add make much difference. I’m running a stock manifold and mounted about 6” below the collector on the vertical downpipe. Finding any exhaust leaks like you mentioned is a good start. Good luck!

ya two headers have two collectors, they they Y into the final collector, O2 sensor is there. It's most likely an exhaust leak I can't detect.

 

[DrRock]

One thing you might consider once you cleaned the o2 sensor and baselined other items is to re-do the initial setup on the Sniper. I did this after my first startup as things seemed off after the first 200 miles or so. Once I did this, all has been fine and the learning/AFR has been spot on.

 

[Rustyj41]

What’s the handheld saying for MAP? I was still seeing good vacuum readings off my manifold with the missing plug.
Looking at that last pic, that hose looks toast. I wouldn’t be surprised if you had vacuum leaks even with a good vac reading.

Also curious how your O2 sensor is mounted. I’ve put 5-6000 miles on the sniper in my 40 and I’ve never had an O2 sensor problem. For guys that this is happening to, are you still in learning mode all the time? What’s your idle speed and target afr’s?

I’ve always left mine in learn. Are you disabling yours. Target ideal is at 800. AFR at idle 13.5.

 

[Skreddy]

I’ve always left mine in learn. Are you disabling yours. Target ideal is at 800. AFR at idle 13.5.

Mine has been in learn for about 5000 miles now. It seemed to have finished learning by about 150-200 miles but I left it in learn.

 

[Seth S]

Maybe I missed mention of it but have you baselined the rest of your truck? Valve
Clearance, timing, compression check, intake and exhaust manifold gaskets and seals, and vacuum leaks?