[Traderssd]

Can anyone help?........We're restoring a '91 Bronco with the 351W and 55K original miles on it.

When we first got the rig, it was doing that typical "Ford truck/Bronco idle surge" thing where it would have a high idle at between 1200 - 1500 RPM and never lower. I replaced the IAC thinking that was the problem but found the real problem to be that one of the computers had gone bad. We replaced the computer and it now starts and idles perfectly at about 800 RPM and accelerates well.

The problem now is that it surges while cruising down the road but goes away under hard acceleration. Not something you can see on the tach but rather can feel and it's really irritating. It acts like it's almost running too lean. Maybe a bad O2 sensor or something to do with the EGR system? I can't find any reference to this issue on the site so I was wondering if anyone might have any ideas. Sure appreciate any thoughts you guys might have.

Thanks a lot
Stuart
Portland, Oregon

 

[Bad Droid]

........ Not something you can see on the tach but rather can feel and it's really irritating. It acts like it's almost running too lean.

Thanks a lot
Stuart
Portland, Oregon

If it was a carburetor model then thats exactly what I would say, too lean and fatten it up a touch. I would definitely start there. Did you check for codes after your latest repairs? It will probably only give basic codes being its pre OBDII but its a start..

 

[Jasonhughes2009]

if your feeling it that could be a sign of the torque converter going out, just my .02