7000 misfire at idle

[captainruss99]

I have an extra complete throttle body setup with injectors, harness, all sensors. runs the same

 

[mbarryracing]

I still say you have a wacky MAP signal at idle from that Cyl #1. Probably the only way to determine that is to check the vacuum on another Viper like you mentioned and compare it to what you see on the gauge hooked up to yours. Even though these triples with individual throttle bodies have very weak vacuum signals, you'd have to just look for a major difference. You pretty much eliminated everything else I can think of without digging down a valve spring or cam lobe rabbit hole...

 

[captainruss99]

There are plugged vacuum ports on each of the throttle bodies, besides the one MAP port. I just checked the MAP port. I will remove the plugs and check each one seperatley, to see if there is a variation between the three. I will also pick up the vacuum carb sync tool from a friend, and see if that tells me anything. I will check the Viper on Saturday to compare the readings to mine. If it leads me to pulling the head off, so be it, not that I really want to. Should have updates by Sunday, for those who are following this mess of a problem. Thanks again to those trying to assist me.

 

[captainruss99]

My boss at my second job unloaded a large project on me, so the sled will have to go on a back burner for a while. The break from it may also do me some good.

 

[captainruss99]

After a summer of storage, I have the 7000 back in the garage. Took a fresh look at it, and found the issue. It was the injector harness. I was twisting and tugging on the harness, there are two junction blocks where wires are connected together. when I was messing around with them, I could cause a breakdown/misfire condition. I believe I made a bit of a mistake last spring. I usually mark all of my new and used parts with a sharpie, as to not mix them up. Evidently, I must have mixed them up on the bench, and put my original harness back on the sled instead of the used one I had bought. Being used, it looked the same as my used one. I have way too much experience for such a rookie mistake. Anyway, it seems to be fixed. I will need to take it to a friends farm field when we get 2 or 3 inches of snow to verify it. I have a picture of those square blocks, if it loaded properly. Thanks to those who helped me with the ideas. I will update when I actually get to test it.

 

[74Nitro]

After a summer of storage, I have the 7000 back in the garage. Took a fresh look at it, and found the issue. It was the injector harness. I was twisting and tugging on the harness, there are two junction blocks where wires are connected together. when I was messing around with them, I could cause a breakdown/misfire condition. I believe I made a bit of a mistake last spring. I usually mark all of my new and used parts with a sharpie, as to not mix them up. Evidently, I must have mixed them up on the bench, and put my original harness back on the sled instead of the used one I had bought. Being used, it looked the same as my used one. I have way too much experience for such a rookie mistake. Anyway, it seems to be fixed. I will need to take it to a friends farm field when we get 2 or 3 inches of snow to verify it. I have a picture of those square blocks, if it loaded properly. Thanks to those who helped me with the ideas. I will update when I actually get to test it.

Glad to hear you got it. Those square blocks do give trouble quite often.

 

[captainruss99]

Well, due to lack of snow, I never got to test drive it locally. On blind faith, I loaded it up for a 4 hour drive for a 4 day ride, hoping for the best. The engine ran great, racked up about 800 miles. On a unrelated note, I did develop a small coolant leak somewhere, leaving some green snow under the sled. Not enough to end my trip, just kept the bottle full. I will diagnose that this week. So, the misfire issue is now done with.