dissapearing heater...

Ive got a bit of a strange problem in my 91 xj. When im driving around with the heater on full (blower resistor must have died previous owner by passed it) when i am excelerating up a hill or hard on flat ground my blower dies right out so theres next to no air, as soon as i let off the gas pedal the heater comes back.

Any ideas?

You have a vacuum leak. Your blower is not dieing, the hot air is blowing out the defrost vents due to the lack of vacuum. Once you back off the gas, the vacuum builds and the vents shifts. Try using the search function. You'll find lot's of info.

Im not sure its a vaccum leak. The engine doesnt hunt it runs fine, and the blowing disapears no matter which vents its coming out of, ill hook a vaccum guage upto it tommorow tho to make sure.

vacuum leak in the plastic lines for blend door