My car 87 gxl, has this weird problem where one minute it will run fine then will have no power, fluctuating idle, engine shakes really bad-worse when I give it gas and give off an exhaust note of a wildy ported engine.



Now so far Ive checked, replaced, fixed-

leading coil

spark plugs and wires

fuel filter

full tune up

pre cats replaced by straight pipe

catco high flow cat to replace main cat

tps set over and over unpluged it too nothing changed

anything else I should check??

Do what ford Techs call "The Wiggle test" basically grab various parts of the underhoos wiring harness and give it a good shake, twist or other movement and see if the problem changes. if it does you may have a bad connector, or loose or broken wire.

Ive done that many times right now I think im gonna put my s6 alt in and re ground my ecu and see if that helps

Check the battery terminals.Got an engine bay pic?

not yet I will update after Im done installing the alt but its too cold outside. I'll finsh when the sun comes back

I just checked my battery terminals my neg. terminal needed alil cleaning but both were fine other wise

Add new grounds to everything. It seriously makes a world of difference.



Reground the lead coil, and the main engine ground. Or something like a new ground going up to the alternator mount bracket will do the same.

it sounds like spark....like its not running on all plugs



it felt like that when i ripped off a plug wire by accident and drove a few blocks....

My car smoked a storm and had no power at all until I spend 4 bucks and regrounded my lead coil, bam no smoke and alot more pull (in comparison to before).



Ever since then I have regrounded anything that has given me a problem and not surprisingly it has usually solved or aided the problem.

Update: due to freezing weather I had to wait a day to finish.

s6 alt. done

ecu re-grounded. done

problem still there not as bad though



Next I will add more grounds and pics