won't idle

[jb513]

So I have been trying to help out my friend with his 03 MM. He puts it away in the winter time and starts it up occasionally during the winter months. This year when he took it out it wouldn’t start. When he finally did it ran rough and wouldn’t idle. He took it to a shop and was told the IAC wasn’t working properly. I got him an IAC from ford, installed it and it fired right up but soon after died. I checked the plugs and changed a few COPs, changed fuel filter then ran a fuel injector kit on it. Once again it fired right up, then died. I pulled a code from it P0511, the IAC faulty circuit . I thought maybe a bad connection and told him to put some dielectric grease on the connection. He called me later that night and said it still won’t idle or run well. Any info would be greatly appreciated. Thanks.

[MOTOWN]

Sounds like bad gas, or a fuel pump about to get ghost! did he put stabilizer in the tank before storage?

[jb513]

Sounds like bad gas, or a fuel pump about to get ghost! did he put stabilizer in the tank before storage?

Yes he put in stabilizer and ran most the old gas out and put in fresh. That's why we changed the fuel filter and did an injector clean. When I hooked up the cleaner to the fuel rail I perched the gas line at the shrader valve and he had plenty of pressure.

[MOTOWN]

If your fuel pump has varnish build up from setting its not going to idle properly, check pressure at the rails on the schrader valve

[MOTOWN]

Just noticed you said you had pressure, what was it at idle?

[B.C. Bake]

+1 on possibly "fuel pump" they just go out, and that's what it sounds like. And when you get it running can you rev it up?

[UncleLar]

I found out after getting an IAC fron AutoZone and having it throw a code of PO507 that the 03's and 04's used different IAC's.
I should've know when the connector on the one they gave me stuck out on the end at a 90 degree angle.Also the openings on the 03 were rectangular and much bigger than the 04 (although the gasket supplied with it had the two smaller round openings like the 2004's gasket and IAC) and so was the piston when I pulled the new one and compared it to my original.
Mine drove fine with the wrong one but idle was way high after starting or hitting the gas and finally dropped down to 1100 rpms.It also started making a honking type noise when it was idling when stopped at a light in gear.

[jb513]

It’s definitely not the fuel pump, Lots of pressure. He can rev it up when he gets it running. The IAC replacement part was bought from Ford using his vin# so I doubt it’s that but I haven’t looked closely at it. Can’t tell what it is at idle because, it won’t idle. The code set P0511 points to maybe a bad connection at the IAC. This is all stuff done while talking to him on the phone after I gave him the new IAC so I guess I’ll have to pay a visit again. I just want to go over there with as much ideas as possible. Thanks for the ones I’ve gotten so far but I could use more ideas Thanks...

[jb513]

anybody out there?..

[HorneDogg]

Have you cleaned the MAF? It could also be the temperature sensor that senses the intake air temperature. If it is reading extremely cold temps it will tell the computer to just dump in gas.

You can also pull off the battery terminals for a few mins, clean them and the cable connections if needed, especially ensure the ground is clean both for the battery connection and the body.

Another thing to look for is a vacuum leak, use a can of cold starting fluid, carb cleaner, or brake cleaner and spray the ends of all the vacuum lines while someone is holding the RPMs steady. If the motor RPMs increase after you spray the vacuum line connection you have a leak, replace the hose or use small zip ties to clamp down and try it again.


Jamie Horne "HorneDogg"
BFE Quincy, Washington
2004 Black Mercury Marauder
2011 Silica Black Pearl Subara Outback
2005 Blue Onyx Pearl Scion xB
1978 Chevy C10 4X4
1974 Pontiac Ventura Custom

[jb513]

Yes I cleaned the MAF with specific spray. We have disconected the battery. I have checked all vacuum lines. I just came back from his house. I cleaned the butterfly and then took the IAC (new) out and cleaned out the ports. When I checked the connection to the IAC there seemed to be a push out, so I took the wrap off and played with the connection. It started right up. took it for a good run and it ran like a champ. Took it back and let it idle for 10 mins. It idled perfect then it just died. It started right up again and then same thing, it just shut down. I double checked the fuel presure and it had plennty. It did this cycle of starting up Ideling for a few mins and then like someone pushed a switch it shut down?? I think the problem is in the connection to the IAC but not sure... Any feed back would be greatly appreciated!!!

[jb513]

So after everything it turned out to be a bad MAF sensor. The car runs like a champ!! Thanks everyone for their ideas..