Idle Surge AU2XR8 - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

ricks · 12-02-2003, 00:52

Recently after I had a fuel pump change on my AU2XR8 (220), when I pull up to idle, engine revs will drop to 500 pick up to 1200 drop to 500 then settle to a fairly rough idle @ approx 850. I have had engine stall on 3 occasions. I have had the car back to the workshop who did the fuel pump change, twice & they can't seem to rectify the problem.
Any ideas????????

svo347 · 12-02-2003, 23:18

Try resetting your TPS setting

ebxr8240 · 12-03-2003, 01:39

TPS and turn idle up its too low to 700rpm.The isc [idle speed control] is trying to stop stalling and causing surge....Adjust with isc disconnected, then re connect...

Latter models may not need to adjust tps as eec resets on start up on eec5's...But voltage should be .9 [or under 1 volt] up to 5v progresivley as throttle is opened..

Check for inlet leaks?? The pvc valve wasn't knocked out while working on engine???. Check that maf is clean...

ricks · 12-03-2003, 03:13

Thanks for the info guys. I have also had a Herrod exhaust (full system) & chip installed since the fuel pump change. I was hoping the new chip might sought any bugs out, but I have only done 250 odd k's since chip install & no change. It has been suggested the chip will take 1500 - 2000 k's to map itself in correctly. Leta hope that the info you have provided, achieves some results.

ebxr8240 · 12-03-2003, 03:19

Suspect chip !!! Na it should run o/k from start what chip?? No crap has followed through to injectors after pump install??? I usually purge fuel at front fuel rail for some time just incase some gets through.

ricks · 12-03-2003, 03:48

Nah, the chip should be cool, it was a unichip reprogammed at Herrods before it was installed.