Ok, here's the setup:

90 Civic EX
JDM b16a/S1 Tranny/PR3 ECU - all stock, bolt ons only at this point.
Bolt ons include: AEM CAI, DC 4-1 header w/extra o2 bung welded in next to the stock location & a custom cat-back exhaust.

Replaced the tbelt/h2o pump/cap/rotor/plugs/wires with swap. Couple of days after everything's running, confirm that the alternator is bad, replaced it with a 91 LS alternator. The new alternator isn't putting out enough juice at higher rpm's - I get the charge warning light above 6k or so - so I'm replacing it tomorrow with a 90 amp 94 GSR alternator.

Problems with swap that have been corrected:
Loose ground wires on the thermostat housing and oil pressure switch.
Bad thermostat - replaced.
Broken TPS housing, causing the TPS sensor plug to come undone - taped sensor plug into TPS for right now, until I replace the throttlebody.

The current problem:
I'm getting hesitation/surge on partial throttle cruising. Either when accelerating or decelerating. Just enough to feel it. At WOT, there doesn't seem to be any noticable hesitation, but I could be wrong, as I can't say I've felt the motor when all problems were fixed. This problem also seems to be increasing in frequency over the last couple of days.

My gut feeling is that this has something to do with the ignition system. I'm not sure if the alternator can have an effect on this problem, but if it does, I'll find out tomorrow when I put the new one in. While I'm doing that, I'll also check the plugs to see if they're telling me anything.

I'm also a bit worried that my non-heated o2 sensors may not be getting hot enough, given where they are mounted. Anyone with a comment on this? I'm considering wiring in a pair of Bosch universal 3 wire heated o2 sensors just in case...

Thanks for any ideas,
Eric

 

Well, I got the new alternator in - it seems to help with the hesitation/surge a bit - it's less noticable now. Checked the plugs - they all look just fine. Unless someone has a good idea on what to check, I may turn it over to a real mechanic. I can fix/replace just about anything, but diagnosing problems just isn't a talent at this point...

Eric