I have an 05 700 EFI. It will start and idle without any problems. It will also accelerate rapidly with no problem I am experiencing a sputter/miss when I am running 5-15 MPH at a constant speed. It will also backfire if I decelerate rapidly from 30-40 MPH. I have tried everything I can think of. It runs fine at idle and WOT. It is just in the lower-middle range that it has a sputter or miss. Any suggestions would be appreciated. I really do not want to bring this thing in to a shop.

I have changed fuel, fuel filter, air filter, plugs and plug wires. I have checked the T-BAP wires (and others), TPS voltage, throttle cable adjustment, intake for holes/leaks and fuel pressure. I have cleaned the throttle body. I have removed and cleaned the coil and connections. I have disconnected the T-BAP and TPS wire harnesses and still have the same issue.

Do you think it could be the coil? Throttle body issue??? HELP PLEASE!!!

 

Check your exhaust manifold, mine was backfiring (no sputtering though) on decel because my maifold was cracked.

 

How many miles and hours? Ever had the valves adjusted? It's just a guess, but I've seen in some cases where valve adjustment has been the culprit of rough running in the low end, top end or even both. If I'm not mistaken, the 500's are supposed to be checked/ or adjusted every 100 hours. BLONDE moment! no adjustment on a 700. DUH!

 

On the 05's we have had quite a few T-bap problems,repair kit #2875542 could solve your problems if backfiring,not idling well or not running good low to middle rpms? Also check the connector coming from the back of the engine from the stator for wires touching the starter and rubbing the insulation off. Also no valve adjustment on the 600,700,800 engines,hydraulic operated valves. OPT

 

I have checked the T-Bap. There was one wire that had the insulation rubbed off. When I went to splice it the wire came (not even a pull) right out of the harness. I have done the repair. I have not looked at the wires coming off the back of the engine. I will look at those now. Have there been issues with the coil grounding out? I have pulled it off, cleaned all the plates and put everything back together.

thanks for the help. Keep it coming.

 

05 did have coil issues. I replaced mine with the newer coil and different mount,

 

Just to update anyone that has similar issues. After tearing apart everything I had already checked for a second time, I noticed that the throttle body adapter (rubber adapter between the throttle body and the head) had a tear in it. SOOOO, that would explain all of my problems. Backfiring due to the lean condition and running rough at 5-15 MPH because of the "extra air" getting into the mix. On WOT the suction on the intake was probably so great that it sucked the tear together and did not allow air in. Sometimes it is just the simple things!!! Thanks for everyone's help.

 

Good to see You goter figured out.

 

to check those for leaks , spray carb cleaner around them while engine is running, rpms will change if they have a leak.