i have a 89 hatch witha 1.6 block and 1.5 dual point head.... the problem is when i push the gas down hard it boggs down and about cuts off but the thing is is when i unplug the bottom injector it will rev up no problem except when i unpluged the bottom injector it idles rough by going from about 2000rpm to 750rpm back to 2000rpm and back to 750rpm over and over .... that is the only thing kepping the hatchie from being on the road. anyone have any suggestions let me know???

-thanks in advance

 

check resistor box.

 

My friend has that same setup...hahahah..

 

when my idle on my hatch was messed up like that it was throttle body make sure ur gasket is good. if you take the intake off start ur car there should be a hole in the inside stick your finger over the hole it might hurt a lil because it sucks really hard, but when u do that ur car should go back to a normal idle if it doe then its ur tb gasket if you need one i have 2 because i just fixed this on my car last week. hope that helps.

 

major your hatch was mpfi, not dpfi...mpfi is different

 

put he still has a throttle body maybe that could still be it

 

i took off the intake manifold off today and made sure that nothing was cloging it and i also replaced the throttle body with the other set of injectors... it is still doing the same thing so i then replaced the ecu with a spare that i had laying aroud... nothing changed... so i changed fuel filter yet again nothing happened... my only guess now is can it possibly be that the timing is off like one tooth? i am flat out of ideas...

 

Well you should of checked your timing first. Do a timing check let us know what is going on then. Shouldn't be anything to bad, could it be a bad Oxygen sensor? Not sure, but correct me if i'm wrong guys. Also try doing a leak down test/compression test.

 

ima do the timing today but i did a compression check a while back and its like 250psi in each cylinder...good compression