- 2002 Accord EX with F23A1.
- OBD1 Swapped
- Motor has about 67k miles on it, longblock was installed with all new parts about 25k miles ago by a Honda dealership.

The car was running great on a street tune before I parked it for a couple of weeks. Filled her up and parked her in the garage.

Had one CEL code at the time which was for the primary O2 sensor (had been bad for quite some time before ever converting to OBD1). I compared part numbers for Denso universal sensors between the primary and secondary sensors, cause the secondary was still installed. Same part number.

So last week when I returned home, I pulled the second sensor, and installed an O2 bung plug in its place. Installed that sensor into the O2 bung in the header just after the collectors merged, and wired it up to the primary O2's wiring. Cleared the CEL and no more codes.

Now to the problem. Ever since I started driving it again, (before and after my O2 mod) the car drives fine in town, keeping it under 3K, but at WOT above ~4200rpm the intake sounds like a banshee, and the car barely pulls. Seriously, we're talking the bark of a K20 swap, the bite of a 300k mile D15.

VTEC is engaging correctly (~2400rpm @ high load), and I'm not throwing any codes. It just sounds like my motor's gonna pop above 4500 @ WOT. I tried a basic tune up, checked the plugs, wires, oil change, and adjusted the valves. Checked for leaks around the block but none, only some oil residue around the VC gasket, and even replaced the gasket. Car runs super smooth at idle and part throttle up to around 4k. After that, it sounds like my intake swallowed a swapped civic with no exhaust.

Bad gas? Clogged cat? I don't know what's going on, and it'll be a few weeks before I can get to my tuner to check things out on the electrical side. Any suggestions?

Changed out plugs, wires, and replaced a leaking radiator cap. Changed the oil and checked coolant levels, all good there. I've run through nearly two tanks with the car acting this way, so I can't imagine bad gas. Swapped in a couple OBD2 ECUs and the car behaves the same way.

If I run the car with an OBD2 ECU, might I be able to find some kind of indicator to the problem if I check the codes and rule out the obvious ones from the swap?

 

Check the timing. A kid in town here had a B20 that did the same thing. So I looked it over and the cams were 180 deg. out of time.

 

Timing was spot on when it was tuned, and the cam/timing belt hasn't been touched since the motor was installed 25k miles ago. Drove it for a week afterward the tune and all was fine. Now, after it sat, it's acting up. Behaves fine when driving normal, but as soon as I push it past 50% throttle, it feels as if I just lost 100hp.

Being that I have to pull out onto a highway from a dead stop and merge onto the same highway a few times each day, my slow 0-60mph sprint becomes rather dangerous.

Possibly injectors or dizzy you say? How do I go about testing those without throwing parts at the problem? 1696 pages and the Factory service manual doesn't cover that.

 

to test the injectors, disconnect the distributor plugs, pull the fuel rail out of the manifold(with injectors still stuck in the rail), have someone turn it over while you watch to see if each injector sprays fuel.

With the distributor, does the cap get hot to the touch at first startup within a couple of minutes of idling? If so, the coil is your culprit on that sort of problem. you should honestly just check the timing and all plugs also. Check your map sensor plug. Rotate the crank until piston #1 is at TDC, then check to be sure cam timing is where it should be. That generally only takes 5 minutes. Good luck!

 

Cool. If an injector wasn't spraying fuel, the car probably wouldn't run as smooth as does right?

I'll have to check the dizzy out tonight. Not sure how timing could be affected, as much as I'd like for that to be the answer. Plugs and wires were already replaced.

 

Pulled off the dizzy cap tonight. Here's what I've got...









Before I rubbed it down with my glove.




Could this be the culprit or part of the reason the car is acting this way?

 

That rotor looks cherry new.

Loud, slow, power fades out slowly sounds like a fuel problem to me. I'd check fuel pressure under load.

 

Exactly the response I was looking for.