Holley Sniper Tech ?

[hammerhead]

Does anyone know how to test the ECU on a Holley Sniper? I have a Jeep with a sniper that began to run very rich causing poor idle and running condition then eventually lost spark. Installed a new ICM and coil still no spark. Gone thru all wires and grounds. Suspecting also the o2 sensor could have thrown off the AFR but unsure if this would cause the loss of spark.

[ZR]

Is it hooked up to control spark?

[hammerhead]

If you mean hyper coil no just hooked to stock distributer. Was running great but then suddenly crapped out.

[5.4MarkVIII]

Is it possible it was running rich due to lack of or intermittent spark. Leading to unburnt fuel? Could be unrelated to the holly system?

[ZR]

What yr / engine Jeep / stock ignition?
If your only using a reference wire from dist to Holley, should be able to disconnect and whirl over to check for spark.

[ZR]

Is it possible it was running rich due to lack of or intermittent spark. Leading to unburnt fuel? Could be unrelated to the holly system?

Absolutely.

[hammerhead]

Is it possible it was running rich due to lack of or intermittent spark. Leading to unburnt fuel? Could be unrelated to the holly system?

When it was running it appeared to be dumping too much fuel it wasn’t a nice flow. It ran like a carb with the float bowl stuck open. I immediately thought it was a fuel and replaced the fuel regulator in the throttle body. Once I lost spark I thought maybe that was the problem - maybe getting weak spark from the coil. I replaced the coil and the ICM thinking the coil may have taken that down too. Still no luck.

[hammerhead]

What yr / engine Jeep / stock ignition?
If your only using a reference wire from dist to Holley, should be able to disconnect and whirl over to check for spark.

It’s an 86 with the 258 six with stock ignition. I’ll check that out I’m not sure if it wires to the distributor direct. I did read a thread last night about a guy who somehow bypassed the o2 sensor to get it running. I’ll have to try and find that thread again. The o2 sensor now is probably pretty carboned up. I read about lots of peeps having trouble with the stock Holley o2. It lost spark while running. I’m leaning towards the ECU just because of the way it was feeding fuel. The battery was 12.3 volts and dropped to 11.6 turning over so the battery is good. Also replaced the fuel reg. Removed the fuel rail and flushed sensors and fuel passages in the throttle body with carb cleaner. Going to try and get at her again tomorrow gotta pickup up a volt meter mine moved out when my son moved out lol

[ZR]

Pick up in the dist are somewhat common as is new ICM being fubar from second one.

[hammerhead]

I was looking closer at the distributor and found the connector joining the wires together feeding the distributor green corroded. May try and bypass the connector and hardwire the distributor see if that works. Going to pickup a volt meter tomorrow and run some tests. Also found on the handheld screen today that I was not getting rpm reading turning over the engine. Last time running the engine stalled and that what is still reading on the hand held screen.

[ZR]

No rpm signal, connection or pick up.

[hammerhead]

No rpm signal, connection or pick up.

I hope so. Been reading a ton of Holley horror stories lol but mostly with the hyper spark systems. This Jeep is just setup on self learn.

[ZR]

We have installed a few kits with no issues. Bulk of the problems we see with electronics installed elsewhere (EFI kits / MSD boxes etc), poor attention to proper dedicated grounds.

[hammerhead]

I didn’t want to leave this short thread hanging. Had a bit of time this week to get back into it.

37148

Unwrapped the firewall harness and found a bad wire spliced into the negative side of the coil from from the ICM. Cleaned up this wire and a few tarnished connectors. Turned the key and she fired right up. She’s running but a little rough because the AFR is way out and it’s not reaching temp. Thanks Rick for chatting this up with me. It’s been a while since I’ve had to deal with these types of issues. I’m very happy it’s running because the owners of this Jeep have had such a rough go. First Covid-19 set their business way back and last year cancer was introduced into their lives. I’ve been helping any way I can including financially to get this Jeep up and running. I still have to sort out the idle and many small tasks to finish up I put aside once it was a no start.

37149

[ZR]

Thats awesome news, even better for a great cause.
Good on you for helping them out like that.