I have the 2.8l 1987 model. It does not idle right. It goes up to 3500 and runs and then goes to1500 then back up

 

need more info. does it sound like its revving that high? third gen tachs are notorious for reading double

 

It does sound and does rev that high. What other info do you need?

 

is it temperature related? does it do it worse hot or cold? does it do it only in park, or will it do the same in gear? if so, worse at highway or slow speeds? any smoke or smells from the exhaust? is it using a lot of fuel? does it hesitate if you rev it? if you rev it, does it hover at an rpm before starting to drop? does it feel like it has enough power or does it take all it has to get to 50?

 

it stays high hot or cold. in park 3000 to 3500 in gear 2000 to 2500. don't know about on the road. smells gase. That's all th info i have for now. If it was reading double rpm's how can i fix it

 

Don't know if this could help there is a 20 amp fuse in the gauge slot where there should be a 10 amp if i put one in it will not run at all.

 

how hard is it pulling through the brakes when its in gear? do you really have to hold them hard to keep it from going? how does the brake pedal itself feel, hard or soft?

i would first check to make sure your throttle cable isnt sticking. remove the air inlet ducting and check the throttle body. there should be no open space around the butterfly. if there is any, check for binding

 

found one problem the TPS is bad

 

that would help solve the issue

 

ya very confusing