[Slow03]

OK heres the deal. Whenever I am cruising in uetral to a stop the car will be idiling normal, then rev to about 1100rpm and dip to about 700 or 600rpm. It does it all the time. I have yet figured out whet in the world it is.

The car did it when it was stock. I figured a full metal tb would fix the problem but it didnt. Only thing differnet on the intake side is a 65mm tb and a CAI.

Anybody have any ideas on what it could be?


To the next problem, whenever the car has sat for a while it takes a little while for the car to start up. I notices it more often when it got colder outside. So I decided to get a new battery. Put the new battery in. After that it seemed to help a little bit but did not cure the problem. I also put a grounding kit on the car, but I did that a long time ago.

Any ideas?

 

[jetrinka]

I would check out the idle air control valve. Sometimes these get gummed up and stick or just get worn out. A bad one will cause the sypmtoms you are having and apparently its pretty common for them to go out on Foci. Seem to be a lot of problems on the boards here with them. I know when I did a wire tuck on my cars engine I accidentally got some solder down the throttle body and it found its way into the IACV. Ran great but wouldn't idle afterwards. Had those same symptoms. Took the IACV off, jiggled it a bit and that solder fell out.... Ran great ever since.

 

[dirtbrown]

tps or bad o2 sensor.

 

[svtf1417]

i have this same problem but here is the weird thing. If im cruising in neutral it will rev up to about the same rpm and dip to about the same UNTIL i come to a complete stop and then it idles like a champ. i have no idea.

 

[Czechmate]

My SVT idles fine but the start up is a little delayed. I got my battery and starter checked and ford told me there were no problems so i left it. Before i bought my car though i read a whole bunch of reviews from car magazines and online car sites and a few of the reviews said that the car took a little while to return to idle.

 

[djmontara]

vacuum leaks? any CELs? any misfires? but i agree with jetrinka.. most likely ur iacv is gunked up.. it will definitely affect both your starting and the over-revving when you dip the clutch..

as for your cold start up problem.. i think of engine oil viscosity.. u are using the recommended grade and type right? ie the one ford says to use.. i believe the foci are quite particular about the engine oil thats in them.. it maybe too thick and of course the colder it gets, the thicker itll get... this can cause problems on start up.. donno, just an idea..

 

[Slow03]

-I do have a checkl engine light but it is from the ORP. Car had these symptoms before ORP install though.

-I am using Mobil 1 fully synthetic 5w-30

-O2 Sensors are good. Front one is brand new.

I was thinking it could be the TPS but the IACV never crossed my mind. Where exactly the the IACV located on the SVT. Same area as the regular ZX3?

Also if the IACV is dirty what do you all recomend cleaning it?

 

[dirtbrown]

id put money on the TPS going out before the IACV....its located on the throttle body facing the battery

 

[SVT_BMXer]

I'm going to go with everyone else on this but also, is your car tuned? You could have an issue with your stock tune.

 

[Slow03]

Car is not tuned yet. Will be soon though. You think I should wait to replace anything until I get the tune?

 

[Slow03]

I have a new sypmtom that I forgot to mention.

I replaced my vavle cover gasket not even 2 months ago and its leaking in the same place again. It leaks right above the thermostat housing where it dips down for the cams. I heard this might be something with the PCV and blowby? I am kinda confused on what to look for.

 

[PoweredByFord]

with what everyone else is saying I would also check out the crank sensor an tps.

same problem I had with my Taurus SHO an my instructor at UTI who was a ford master tech instantly said the crank sensor so I replaced it an no more dying, crazy idle, an eractic starting problems.

 

[JK03SVT]

My car had the same issues that you are having. I replaced my IACV and the idle problem disappeared. As for the starting problems, check your plug wires and plugs. I somewhat had the same problem like that but mine wasn't really a worry. I changed over to Screamin Demon/Livewires combination and noticed a better start than before.

Not that you have to do it, but it is a recommendation. Grab a new IACV from Ford instead of Autozone or equivalent. I noticed that several sensors I bought as replacments from Autozone actually made the problem worse. IACV at Ford is something like $70 but worth it.

 

[Yocrew]

id put money on the TPS going out before the IACV....its located on the throttle body facing the battery

This should be your problem. Since you have a CAI you might gotten water on the TPS causing the high revs.

 

[Slow03]

As far as plugs go, I have the Motorcraft Coppers, Taylor thundervolts and stock coil. All tight, nothing loose.

Ah you guys are confusing me. ONce I think it is the TPS someone else says its the IACV. I want to try and clean the IACV first.

What can you clean that with?

Also I noticed something today about the idiling. Car was almost at correct temp. Only been running for about 10 mins. I turned the heat to 1 and it started idiling a little funny. It was going up and down but only maybe up and down about 100rpms. I can notice it a lot cause I have the VF rear mount and I felt it shaking a lot. I then turned the heat off and it was back to normal symptoms.

I plan on ordering the TPS tomorrow and if it is in stock then I might try and put it on when I get off.

 

[JK03SVT]

Almost starting to sound like an alternator problem as far as when you turn your heat on. Check all of the above. From a personal experience stand point, a new or "cleaned" IACV worked for me. It could be the TPS. I haven't had one of those go out yet, so I can't rule that out. Yocrew may be right. When in doubt, check them all.

 

[JK03SVT]

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[JK03SVT]

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[JK03SVT]

^^^ hit the button too many times. sorry.

 

[orange04s281]

I have the same startup problem but my car seems to hold rpm ok just shakes the car alot. its an 05 with only 35,000 miles. I change the syn oil every 5000 and use 5-20 so I dont think that is the problem.