nj0127

Credentials:
97 civic
obd2a-obd1 v2 jumper harness
complete obd1 ls swap
p75 obd1 ls ecu
What looks to be like a d series throttle body? measured to 56mm give or take .100ish
ex harness converted to obd1
used obd2 injectors to avoid splicing harness more then i had
Vehicle Currently throwing a code 14 for the IACV
rpm gauge shoots all the way around to the very bottom upon start up, and on occasion will fluctuate very aggresively depending on the amount of throttle given.
vehicle is currently in limp mode, and backfires more than anything ive heard in my life, when you first start up and drive it runs smooth to 3000rpm then acts like theres a rev limiter , after about 2 min of driving it starts to sputter and backfire more, still holding out giving no more than 3000rpm.
now when i rev it up by hand with the butterfly you can hear the intake sucking in more air the higher you rev, but it just bounces around 3000rpm
- we tried swapping out the ls with the only other ecu we had laying around a known good obd1 p14, but still no difference.
Checked for misfires and all cylinders are operating normally. compression reads 160/150 /150/160
kinda feelin like this right now
i know im just one step away from finishing my swap, but im stumped on this one. What else should i be looking for now that the ecu has been ruled out.

grumblemarc

iTrader: (4)

Unless it's something simple like swapping the MAP AND TPS sensor plugs around I've NEVER seen anyone solve these "Won't rev past.." issues after they've done a swap.

nj0127

yea just for ***** and giggles i tried swapping the tps and map plugs around, it started idling worse, im probably gonna double check my distributor wiring tomorrow, but im thinking either way if my distributor wiring was off it would throw some type of distributor code, and possibly gonna try a rywire jumper harness and see where that takes me. When i first got the car 6 of the wires on one of the junction plugs had torn off, so i had to do alot of soldering on that side as well.

nj0127

Could the smaller throttle body be throwing off the tps or map readings? therefore causing it to run limp?

grumblemarc

iTrader: (4)

Test the TPS voltage. I doubt it.

nj0127

well after further diagnosis, and correcting a simple mistake ive found the issue, or so i think i have, i misread the code , its throwing a code 14, i checked resistance at the distributor plug, then checked continuity, at the wire harness, the wire harness showed 5 ohms of continuity, i unplugged the ecu, plugged the jumper harness to my engine wire harness and measured continuity from the jumper harness ( ecu side) and got a reading of 2200 ohms, kinda high, i compared it to other sensors such as the tdc sensor and cyp all show readings of 5 ohms, so my conclusion is there is a break in the ecu jumper harness circuit , i will be getting in contact with the company i purchased it from and either asking for a refund or a replacement.