Author Topic: Missing at only a certain RPM (Read 3725 times)

bvolks73 · « **on:** February 27, 2008, 02:16:38 pm »

I noticed while boosting my brother's car the other day that my Jetta (85 N/A) misses/ stumbles at a certain RPM, just a bit above idle. He had mentioned that he noticed a miss every once in a while while driving though I never have. I don't have a tach so I can't tell what RPM it's happening at but it's very consistent, never a miss below or above that RPM. Car seems to work ok otherwise, except for pressurizing the coolant a bit. I hauled a 1/3 cord of wood with it yesterday with no problems. Any idea what it might be?

zukgod1 · « **Reply #1 on:** February 27, 2008, 02:31:16 pm »

Until you eliminate the head gasket problem from the equation I dont think we can help much.

jtanguay · « **Reply #2 on:** February 27, 2008, 03:02:40 pm »

do a pressure check... make sure the engine is cold and take off the cap. put it back on and start the engine up. run it for about a minute and take the cap off while its running... if it has built up pressure in that small timeframe then its most likely the head gasket.

the missing at upper rpm's could possibly be lack of fuel... any wet spots under the hood near fuel lines??? check cloth lines and lines near the fuel filter.

bvolks73 · « **Reply #3 on:** February 27, 2008, 07:11:11 pm »

I did the pressure test and I'm sure the head gasket is getting bad but I figured the miss at a certain RPM could be something else. I see no wet spots or fuel leaks anywhere.