Top misfiring

About a month ago I scored a great deal on a 1988 turbo coupe canyon red with a 5-speed. I've since been fixing little things here and there and reversing PO's "Mods". I found he had v8 plugs in, not the 4 cylinder ones so I swapped with a set of copper motorcraft plugs. He said he had the timing advanced so I've been turning it back in small increments but can't seem to get ride of the miss. I've turned the boost down from 17psi to 14 or 15 and that doesn't seem to help. Pulls and spools good with part throttle but wide open starts randomly missing missing after 4K rpm. Vac lines feel solid. Any ideas?

What kind and how old on the plug wires? We recommend the Motorcraft wires: Motorcraft: WR-4011-C
These things are temperamental about plug wires. Lots of brand don't work.

Good to know, no they're not motorcraft. I would like to do a CoP setup in the future or a coil pack at the least when I switch to pimp.

This sounds like to me that you have a problem with the VAM. Mine does the same thing. I dug around through my spare parts and found another one and the full throttle miss went away. But as of late, it has came back. So for me, a MAF is in order.

Jim B .

Man I can't wait to ditch that thing! I really want to PIMP it lol

I've read a MAF swap isn't easy without aftermarket engine management, is this still true? I have a 90mm lightening MAF lying around I would love to put on.

would a maf and throttle body from a 2001 v6 f150 work?

Any MAF could be made to work, I would try to find a 6-wire though.

It is not easy to get a MAF to work right with the stock electronics. Jeff K knows a lot more about this than I do. With aftermarket engine management like the Pimp it is unnecessary since the Pimp uses a MAP sensor instead.

Swapping to MAF definitely isn't plug and play.. and it will need to be tuned, that's a requirement. I'm running an '03 Focus slot MAF in my setup. Quarterhorse on LA3 using a MAF binary that includes the additional MAF backflow code.

Plug gap was wayyyyyy off. Regapped to .035 and installed motorcraft plug wires. Still a tidbit misfiery after 4K rpms. Is there anyway I can rule out the VAM as the culprit? Vac gauge shows the motor pulling around 18 at idle.