RPM's DROP AND GO UP AND DROP

[herb165]

1998 GTX LIMITED 951,HAD IT OUT THE THE LAKE 2 WEEKS AGO AND RAN FINE,TODAY WENT TO THE RIVER AND SEEM TO RUN GOOD FOR ABOUT 1/2 HOUR AND THEN I WHEN HIT ABOUT 6100 RPMS IT WOULD DIE DOWN (NOT STALL OUT) TO ABOUT 4800 RPM's AND WORK ITS WAY BACK UP AND WOULD BOG AGAIN.BETWEEN 5800 AND 6100 RPM's IT DROPS AND NEVER CUTS OUT BUT CONTINUED TO DO IT SO I PUT IT BACK ON THE TRAILER,I FINISHED MY BREAK IN ON THE MOTOR A FEW HOURS AGO AND MAY STILL HAVE A LIL HEAVY OIL MIXTURE IN THE TANK BUT I DID NOT PUT IN ANY FUEL SINCE LAST TIME I WAS OUT,IDLES FINE AND RUNS GOOD TO THE DEMON RPM's

 

[LouDoo]

Have you cleaned your rave valves lately? It could be the extra oil has gummed them up. Also check the spark plugs.

Lou

 

[Dr Honda]

First... turn your caps off.

Second... do you still have tempo fuel hoses? You are describing plugged carb filters.

 

[herb165]

Copy on the caps,took the fuel filter out and it had alot of sediment inside the screen and the plastic bowl(looked like mud),the screen has a micro fine rip in it and will replace tomorrow and it does have the grey tempo lines

 

[El Toro 33809]

That's how our 99 GTX LTD ran before we changed the fuel lines. Change them and clean the carbs/filters and fuel selector.

 

[herb165]

Will try that,thanks alot.

 

[herb165]

Is their a certain fuel line that is better than another.

 

[Dr Honda]

Just replace it with rubber automotive hose.

 

[SabrToothSqrl]

Doubt it's the problem, but verify the operation of the water regulator as well.
Also, new plugs after that first break in tank.

 

[msmith53]

Copy on the caps,took the fuel filter out and it had alot of sediment inside the screen and the plastic bowl(looked like mud),the screen has a micro fine rip in it and will replace tomorrow and it does have the grey tempo lines

I had the same problem with my 98 GTI...would surge/drop at high rpms...did the same thing mentioned above and it fixed it 100%. Cleaned the bowl and the inside screen, and now it runs great...no surges.