Dave in balto

SOLVED: ( MISMATCHED AND DEFECTIVE ECU replaced ECU, runs like a champ)

Hey. 1997 5gen prelude, 5 speed, swapped H22A running on a P5P JDM ECU. Was running a H22A4 well on this ECU, now, it won't go uphill and can't get above 2100 RPM, pedal to the floor. I have examined the harness and unit, and have found the PO did a few wiring mods in the harness. New to Honda so don't have a feel for whats going on. Swap was done by competent mechanic, but they're asking me to get a scanner that can read this ECU. Just tried that and got a Comm error on all modes. Suggested next steps? Thanks.

TimiK

if its in limp mode whats the codes?

AndyD

iTrader: (1)

Have you checked for any vacuum leaks? I one time had a weird issue like this when the intake tube wasn't secured to the throttle body properly.

Accordian47

Do you have a check engine light? If you had codes, it'd be on. I mean it's always worth checking with a scanner regardless of whether its on or not but it sounds like your having trouble scanning.
First step would be to get a scanner that can communicate with the JDM ecu (I'm assuming thats the problem)
Could be a bad sensor (MAP/TPS etc.), vacuum leak, bad ground (engine harness/intake manifold sensor ground), bad ecu, fuel problem (injector clogged, fuel filter clogged, low fuel pressure), ignition problem (bad coil, faulty distributor).
Does the engine rev, unloaded past 2,100RPM? What does the engine do when driving once it hit 2,100RPM? Does it just bog out or does it misfire?
What engine harness are you running? What distrubutor?