1996 ford aerostar xlt all wheel drive, 4.0 litre 96,000 kms
I had the cyl. head replaced along with all gaskets above the piston level. Work was done by ford mechs. where I bought the van new. As soon as I picked it up it misses or "chugs" like crazy mostly when driving flat and level at 57-63 kmh, when the throttle is lightly depressed.
It has been back in the shop 12 times in the last five months to fix this without results. all computer specs are o.k. parts replaced, plugs, wires, coil, engine vac, egr, both egr control boxes without success. If the egr is unplugged the van runs perfect with the check engine light on.
Ford mechs are baffled... :banghead: :ohcrap:
Have someone hold the brake while in gear an accelerate until this starts happening, and check manifold pressure at that point. Then check it at just enough gas to were it runs fine(above the previous point), then check it at idling speed in gear. Let me know these figures. We can start there. Make sure fuel injector harnesses are plugged in tightly, and are clean inside and out. Make sure fuel rail is tight on fuel injectors. Make sure they're are no vacuum leaks around fuel injectors.
I am copying your suggestions and will pass them along to the mech. I am not actually doing any troubleshooting myself as this is their problem. I paid $2500. already for the orig. repair job and am not paying a dime more. Therefore I am looking fo advice that I will pass on to them. (I am not toooo mechanical so I don't want to bugger something and give them any reason to blame me) Van goes back in 2 days, all your suggestions will be left on the drivers seat. greatly appreciated :thumbs: