Running issues after swap

[Kroenen]

I’m nearing the end of my swap into my gen 2 surf, but I’m having some running issues. The car starts fine, but seems to be running incredibly rich, even after getting up to temp. Also when you rev it, it really starts popping and banging towards the top of the rev range. It almost sounds like it’s bouncing off a limiter, but it’s nowhere near redline.

I’ve checked the tps, and have new o2 sensors and efi temp sensor ordered. Anything else I should be looking at?

 

[gloverman]

Which version of 1uz did you use? Have you confirmed the iac reset is correct? Have you checked codes or have access to live data?

 

[Kroenen]

Ufc20.

I actually looked at your iac reset video, but my iac looks quite a bit different. You can’t see the plunger, just a small hole when you take it off. Mine also has an additional coolant pipe that goes into the top of the thermostat housing near the top hose.

I pulled only one code which was 12. As far as I can tell this is rpm signal bank 1?

curiously I was checking the timing wasn’t a tooth out, and when I had the timing light on it, cylinder 1 was only strobing intermittently.

could this be as simple as a cam position sensor?

 

[Kroenen]

Well I checked the resistance of both cam sensors and crank sensor, and they’re all reading 1k ohms when cold. Strangely, plugged everything back in and it seems to run better now, so must have been bad connection. Still shows code 12 though, and when it gets hot, the idle is hunting up and down constantly.

 

[gloverman]

Ok.

So you have checked the codes and gotten code 12.
When checking the resistance did you do it cold only or again once the engine warmed up and was faulting again?

Which version of 1uz did you use? Maybe the ecu number would be helpful.

Did you actually check the IAC reset? The principle is the same regardless of which version of IAC it is.

 

[Kroenen]

I checked the sensors cold and hot. 1k ohms when cold, 1.2k hot on all three.

Its a UFC20 with ecu 89661-50251

As for the IAC reset, I’m a little confused as in your video you had a spare, which I don’t have, so not sure how to carry out the reset. Am I just blanking the air hoses?

 

[Kroenen]

Figured I should update this with the fix. As Kelvin correctly suggested, carrying out the IAC reset cured the problem. Had to make a plate to blank off the inlet plenum, then a few starts seem to have fixed it.

Thanks again for the help!