Boss Engines with full Herrod Exhaust - Idle Speed/Sensitivity - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

burnsi · 12-16-2003, 01:33

Did anyone notice that their idle speed seemed to have reduced after the Herrod (full) exhaust was fitted?? I'm not sure that this actually happened, or just seems to have happened.

Also, the sensitivity around idle seems to have increased. For instance, if I blip the throttle, engine revs obviously rise, then sink below the normal idle revs of about 650ish rpm to about 450 rpm, then return to normal. Also, if i manually try (with accelerator pedal) to get it to idle at above the normal idle speed, but not above say 1100 rpm, the engine gets all cranky and revs start to swing up and down - sometimes (twice now) stalling!!

If the car is left alone to sort out idle speeds - all seems to be OK.

Interested in your experiences.

GTP 320 · 12-16-2003, 04:10

I found that the idle does vary sometimes but have put this down to a re mapping to be done in the future at Herrods when i will get it dynod.
Cheers John

GTP193 · 12-16-2003, 14:42

Same thing here. Have been toldt this is because its electronic throttle. If you watch the tacho when you just move the steering wheel the rpm hunts slightly. Air con on will make the rpm hunt. My car is set at 630rpm. Idle increase to about 720 rpm while trying to settle after a run.

Charliewool · 12-16-2003, 15:28

Mines the same!..... And with aircon on, & on a hot day the idle falls & sometimes stalls!
Only been happening since the onset of really warm weather though.

sniper545 · 12-19-2003, 20:03

This is happening to many of my GT friends that have had the exaust changed. it does make the engine feel lumpier at idle, and as the engines loosen up after a few thousand Km's, they finally settle down to a nice rythm. Keep an eye on it though and let me know if you want our techs to have a closer look.

GTP 200 · 12-20-2003, 17:32

I had that issue but after 10,000 it went away.

cam

yatesy · 12-30-2003, 01:56

Ditto, same problem.. Thanks guys for the info, i'll keep an eye on mine and see how it goes... the only other thing i've noticed since having the full system fitted is now sometimes the car will not start on the first press of the starter button, simply winds over... stopping then trying again after about 5 secs gets it firing straight away... anyone else had that problem?

stricky · 12-30-2003, 14:44

A hunting idle with the aircon on seems to be worldwide Ford feature

XRFPV8 · 01-08-2004, 21:29

Quote:

Originally Posted by GTP 200

I had that issue but after 10,000 it went away.

cam

hi Cam, your on the mark had my Herrods headers put two weeks ago had 9200klms on the vechicle, now i have just over 10,000 klms and idle has settled down.

thx...

smokinjoe · 03-30-2004, 03:30

have your ford dealer check the operation of the canister purge solenoid, some are causing this very concern. Exhaust mods seem to highlight this problem for some reason. My s/c BA with 350+kwatrw had same issue.