[pappy60]

I have a small problem. Car idles badly I changed spark plugs and it got worse.Cleaned throttle body,IAC.New plugs Autolite 104's & new NGK 8mm wires. New PVC hoses and valve. Car runs fine except when is sitting and idle. I have had bogg down a couple times going uphill the hill was really steep. but car acted like it wanted to stall when you gave it gas. Any thoughts.

 

[amc49]

TPS switch can do it but if ATX be prepared to buy the entire throttle body to get one. That has nothing to do with higher load like going up hill though. You are nowhere near idle then.

Motor condition could play here. Mileage? Fuel pump ever been changed? Which motor?

 

[sailor]

Autolite 104's are for the duratec engines, Zetec is different & I'm not sure on the SPI.

 

[amc49]

No duratec in '02, sure about those plugs OP? I personally do not memorize them.

 

[pappy60]

Has the Zetec dohc with 172,000 Had the car for 16 months never replaced the fuel pump. Car starts without any issues and runs with no issues just idles badly.
Here is a list of what I have done to the motor since I have had it
New timing set and water pump
New thermostat and housing
New plugs and wires
New PCV hoses
New fuel filter

 

[rhowe]

I'd cover some basics and run some injecter cleaner or seafoam thru it.

 

[amc49]

Compression check to make sure you're not wasting your time. Low compression results in crap idle and low overall power. Coil changes just like plugs on those. Can be coil connector too.

 

[pappy60]

Update compression check everything ok. Put in another set of plugs and smooth out some. Think I will try a new IAC had it off once and cleaned it. What a job getting it out. Have seafoam it and I use stp injector cleaner regularly

 

[Leora83]

I've heard of people having success cleaning IACs, and some having none and just having to replace it.
Check your coil and connector...both my Zetecs have had the wires fail right at the plug, causing poor idling and bogging under load. Did it for weeks before actually throwing a code.