I'm having a rough idle problem.
when the engine is cold, it idles fine, but after a good run on the highway, it idles like crap ... almost stalling and running rough.
Changing the plugs helped a bit.
I'm wondering if the TPS or the IAC valve has pooched.
Any ideas?
What engine? Any hanging rpms??
(03-27-2012, 10:32 AM)Platinum6316 Wrote: [ -> ]I'm having a rough idle problem.
when the engine is cold, it idles fine, but after a good run on the highway, it idles like crap ... almost stalling and running rough.
Changing the plugs helped a bit.
I'm wondering if the TPS or the IAC valve has pooched.
Any ideas?
Could be those things - I assume we're talking Zetec. Have you cleaned your MAF lately - no vacuum leaks?
if IACV is not function properly, there must be engine code popping up.
r u getting any engine code?
My SPI was running poorly once out on the highway. Replaced coil pack. (Went with MSD)
Depends on the engine. Coil pack can be bad if it's a SPI, as mentioned, or it could be the 3-wire harness going into distributor on a Zetec. If any of those wires are pooched, you'll have to get the replacement harness from Ford. Also, depending on KMs you could replace sparkplug wires and sparkplugs.
Check your plug wires, coil pack and plugs. I've only put 130k on my SPI and had to change all three at around 120k.
OK, I see I didn't provide enough info, sorry.
It's an '02 with the Zetec. about 145000 on it.
I've changed the plugs and the wires and the air filter.
I'm not getting a CEL so I don't have any codes.
I'd start getting into the Maf sensor and iacv... You can take the iacv off and clean it with some carb cleaner... I'm not sure what people use to clean their Maf sensors
(03-29-2012, 08:04 AM)MuskokaZX3 Wrote: [ -> ]I'd start getting into the Maf sensor and iacv... You can take the iacv off and clean it with some carb cleaner... I'm not sure what people use to clean their Maf sensors
There is actually a specialized MAF cleaner - at least in the US there is. But I think any non-chlorinated cleaner would do - even straight alcohol.
Bad idle can be soo many things. I had a horrible idle where my car would pretty much die at idle. I swapped my coil pack. Wires. Spark plugs. And found a nasty vacuum leak. That solved my problem lol.
vac leak is what i put my money on. check all hoses and make sure none have rotted out on you.
if not, revert to other options listed lol
Thanks for the great suggestions! I'll have a look as soon as I can get to it.
It's def a vac leak if it gets worse when it's more damp out. If it's shite 24/7, it's likely coil, sparkplug wires or the sparkplugs themselves.
OK, so after sticking my head too close for my liking to a running engine (managed to not get injured though, WHEW!) I hear a vac leak. It appears to be the hose that snakes around the intake manifold and leads to the fuel pressure regulator. Any way of replacing this easily? I don't want to dismantle anything I don't have to, ESPECIALLY the fuel rail or intake manifold.
I pretty much have the same issue with my 02 ZX5.
I've already replaced the plugs, cables, coil pack, coil pack pigtail, pcv valve, pcv hose, MAF, and the evap vacuum hose and it still idles rough.
Next up is the IAC valve and DPFE sensor and hopefully they fix it.
try adjusting the idle set screw on the TB itself? thats what i had to do with mine
My thought would be what happened to my car could be wrong with your car. There's a rubber hose from the valve cover that goes back to the firewall area and connects to a sensing unit. The hose gets soft and breaks at the bend to the sensor unit, very hard to see unless you take the hose off. But if you reach around back (engine off) you should be able to feel any soft spots (where the leak usually is). Long shot, but my best answer.
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