3.0 V6. This vehicle has been sitting for some time without a battery and with a bad starter. Replaced the battery and starter and it started, but idles rough. Give it throttle and it increases RPM verrrrry slowly. Put it in drive and give it gas and it dies. It was parked because it did this, i.e., started running rough with no power while it was being driven, so the the driver brought it home immediately, then it died when it was parked. A short time later an attempt was made to start it and the starter just whirred without engaging the flywheel. At that point a new starter was purchased, but stored in the car overnight. It was stolen and the battery was stolen, so it sat for a while.
NO CODES. So, it's gotta be air, fuel or ignition, but which?
Any thoughts?

Air filter is clean and nothing is blocking the intake. Could be the MAF--any way to test that with an ohmeter?--but that would throw a code. Could be the TPS, but that would throw a code also. But can that be tested with an ohmeter? Could have a bad or dirty IAC valve, but that should just affect the idle... Could be a collapsed catalytic converter I suppose, but shouldn't that throw a code also???

Could be a fuel problem I guess. Dirty filter, bad fuel pump, bad fuel pressure regulator or even just bad gas. Any idea where a fuel pressure test valve is on the fuel rail or where the fuel filter is? I don't really want to pull the fuel pump unless I know it's not putting out enough pressure.

Having suggested all those possibilities, my experience tells me it's electrical--that is, ignition. Coils, plugs, ignition module or maybe even the computer. How do you test the coils? Most cars have a maximum/minimum resistance rating on a coil. Anybody know what it is for these coils? Where is the ignition module and is there any way to test it, or can a parts store do it? On the other hand, there should be codes being thrown for ignition parts failing too, shouldn't there?

Lots of questions--sorry, but this thing has got me puzzled and I'm not used to working on Fords, having owned very few of them and never one this new. Any help appreciated.

kjhansen

 

Well, no replies, but the saga continues. I still haven't been able to test the MAF or the TPS, but there's a test you can do for a clogged catalytic convertor. You attach a vacuum gauge to an intake manifold vacuum port and you maintain a steady rpm. If vacuum stays the same, no problem. If the exhaust system is clogged, burned exhaust gases will be forced up into the cylinders, thus reducing the amount of air that can be pulled into the cylinders, so vacuum will drop steadily. It didn't drop at all--it stayed steady.

Also, I found the fuel pressure test valve on the fuel rail (it's right under the plastic air tube that goes into the throttle body--you have to remove the plastic tube and the throttle body to get to it) and hooked up a pressure gauge. Mitchell's Engine Performance Manual says the car should run OK with fuel pressure from 35 to 65 PSI. Fuel pressure was a steady 65. So I guess the fuel system is relatively clean and functioning properly from the fuel sock to the injectors. I didn't check the injectors though--didn't want to take the intake manifold off. I have a noid injector tester, but you can't get to the injector connections without removing the entire intake manifold.

So that leaves electrical (probably ignition) problems (maybe). Surely there must be someone technical out there that can tell me how to test the MAF, TPS, coils and/or the ignition controller, whether that is an ignition module or the powertrain control module (computer). Mitchell's says to put it on a diagnostics computer and review the readings for the MAF, TPS, spark, timing advance and computer control. Since I don't have a diagnostics computer I can't do that. Oh, and don't test timing with a timing light because it will give you false readings... Hmm. Plus, now it's throwing a code which I can't read because I don't have a scan tool.... and I can't get it to a parts store that does free code scans because it won't move.
kjhansen