06 900 missfire at @ 6700 RPM

[Colorado Kid]

Runs great to @ 6500-6700 and then starts to cut out until you get under this RPM range. Any ideas????? Not sure if this is when the upper injectors are to start coming in? Do I have a bad connection to an injector or just a bad injector?

Help please!

 

[Cerialsledder]

Runs great to @ 6500-6700 and then starts to cut out until you get under this RPM range. Any ideas????? Not sure if this is when the upper injectors are to start coming in? Do I have a bad connection to an injector or just a bad injector?

Help please!

When was the last time you checked you exhaust valves?

 

[SixtySevenGT]

Exhaust Valve Solenoid

You don' need to have the Vacum lines hooked to it, but it needs have the electric part pugged in or it will miss at at about that RPM. The ECU senses it.

 

[Colorado Kid]

Thanks for the suggestions.

Thanks for the replies on the exhaust valves as I have not checked them for a bit, I was stuck on an electrical issue with the injectors.

 

[Cerialsledder]

Thanks for the replies on the exhaust valves as I have not checked them for a bit, I was stuck on an electrical issue with the injectors.

So did it work? lol

 

[Colorado Kid]

Still missig

Cleaned the exhaust valves but this did not resolve the misfire. Did run a voltage check on the TPS and will generally see a slight break in the readings at 1.98 t 2.0 volts but then is steady after 0 volts. If there is a slight break I the voltage reading in the TPS, will this cause it to continue to miss at all RPM ranges above this level? Once I bring the RPM's down below this range, it runs fine again.

Any ideas?

 

[garlic bear]

It could be the tps...had a similar issue with mine would idle but would break up when reved up..Changed the tps and all was good on mine

 

[Cerialsledder]

I have a spare tps I can let go if needed.... Let me know

 

[guidoxpress]

Dead spot in TPS
Bad TPS harness
Hole in Exhaust bellows
Clogged Fuel filter
Chipped Reeds
Improper gap on plugs


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[Fuse900]

I would say dead spot in TPS. In addition, if you don't have the best quality tps adjuster, it's worth the money to have it set at a trusted dealer. My home made TPS adjuster could not get precise enough values to set the TPS correctly. Out of 5 Radio Shack resistors, none were in spec, 1 was close (.01v variance) so I used it. My sled would run, but cut out and surge at 4500 rpm. Took it to my local dealer (first time I've paid for labor on my sled) and for $50 it was done and my headache was gone.

 

[Colorado Kid]

Finally got it.

Thanks for all the suggestions on possible causes of the misfire. Replaced the TPS with known good one, no positive results. Had dealer readjust TPS and replace exhaust bellows, no positive results. Changed the fuel filter and installed new reed petals, now runs through the entire RPM range very strong. Not sure if it was a clogged fuel filter or weak reads but glad I got it to perform well again.

Thanks again for all of the input and suggestions.

 

[guidoxpress]

I thank u for the update. It's very frustrating for us to help ppl diagnose their sled and then never get feedback. This helps us with others and helps others learn preventative measures.