Low Power

Been having issues with loss of power. I feel good pressure in the motor and exhaust but it feels like its being held back. As far as I can tell there isn't anything loose or any vacuum leaks. There is an exhaust leak at the head due to a snapped off bolt. Odd thing is that I had this issue before for a few weeks and it resolved itself on its own. Its an 87 with the 4.0, any ideas? I have about 30% power I would guess and the only way I can get any decent acceleration is to drop the pedal to the floor. I alsohave issues with the exhaust/motor doing a hiccup when trying to accelerate.

Catalytic converter could be clogged.

Doubtful, 3 months ago I had a complete exhaust system put on, from the end of the manifold back.

I'm gonna do a full tune up this weekend, plugs, wires, cap, rotor, fuel filters, air filter and vacuum lines, plus check the cylinder compression. Is there anything else I should do for the tune up?

DT|Ac1d said:

I'm gonna do a full tune up this weekend, plugs, wires, cap, rotor, fuel filters, air filter and vacuum lines, plus check the cylinder compression. Is there anything else I should do for the tune up?

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Yes. Use only Champion or NGK plugs. Use only distributor caps which have brass terminals instead of aluminum. Napa wires are good. Don't go El Cheapo on those. Clean your throttle body with an oxygen sensor safe cleaner along with your IAC.
Check all your vacuum lines and CCV grommets for integrity.

What's an IAC?

Idle Air Controller, an electrical item, and it's located on the front of your throttle body, closer to the head than the Throttle Position Sensor aka TPS..

Oh that reminds me, ive been having issues with my idle as well. Sometimes it will idle really high. Sometimes its only 1500 other times it can go up to 2200rpms. It varies how long it does it. Sometimes it will go away after 10 min our could last the whole 40 min trip to work. I would say it does this about 20% of the time. Could this be a bad IAC?

Clean your throttle body as part of your tune up along with your IAC. We'll go from there.