My b2/z6 mini me ef tachs out at 3500. B series throttle body, chipped automatic to manual p28, cam gear has not been changed to y8 yet to compensate for half tooth retard but distributor is fully advanced toward the firewall. I can start and drive it but it's just like hitting a rev limiter. Doesn't try to die at all. I only have a code for the O2 heater circuit (41). If someone could point me in the right direction to solve this that would be great. I would suspect the crank sensor in the z6 distributor but there is no code. I've searched for solutions and found none. Thanks again.

 

What distributor and injectors? Fix your cam gear issue as well

 

D16Z6 distributor, OBD1 injectors (the ones that came on the Z6 that shouldn't need a resistor box), and you don't suppose the timing issue would cause this? Also I had codes for both the crank and cylinder one position sensors and solved it by soldering my own connectors from the wiring harness to the distributor which made it run much better and left me with this.

 

Also I am using the OBD0 MAP sensor on the firewall since the head I bought didn't come with one. It has never thrown a code so far.

 

Sorry I read that as cam gear advanced not distributor. The 41 code shouldn't cause the limiter. What trim is your civic, ex, si, etc?

 

It is a 1988 Honda Civic LX.

 

Did you convert the DPFI to MPFI yourself or buy a harness?

 

I converted DPFI to MPFI myself and put an eBay OBD0-OBD1 harness on that. I checked the wire routing before I put it in and everything went where it was supposed to. I think my injector wiring could be loose though since my distributor wiring was. So I'm going to try to look into that today before work.

 

Something I just thought of, my car is running an open header right now because my brother lost the header bolts. So my O2 is exposed. So that would make my car think it's running really rich or lean and then the ECU would compensate with limp mode to save the engine (lean) or save the catalytic converter (rich), right?

 

I know you don't have a code but check out this recent development (actually has been going on for a while but now confirmed) as this would cause the 3500RPM wall.
https://honda-tech.com/hybrid-engine...tions-3235473/

 

That's crazy! Mine has c1 (obd0) cyp spliced into c16 (obd0) O2 and then ran into b15 (it may have been b16 both are cyp) (obd1) cyp! Same thing! I'll definitely look into that. I guess I assumed the extra wire was for grounding purposes or something when I checked the harness. Thank you very much. I'll post back results after I try this. It will probably be tomorrow afternoon. I have to work tonight. Sounds promising though for sure!

 

That was the solution! The creepy part is there is no code for the 02 sensor. It could be my computer. There's no telling what else it is chipped for! Now all I need to do is get it to idle correctly. My IACV is throwing codes intermittently so I'm gonna see if there's air in my lines and then replace it if that doesn't fix it. Thanks for your help! I hope this post can help someone else out.

 

Have you cleaned the IACV first?

 

 

We sprayed it out with carb cleaner before putting it on the head. I'm mainly concerned with why when I unplug it the engine dies completely because I'm unable to get the idle up to 500 or to even idle at all with the idle screw without forcing the throttle plate open with throttle cable adjustments (I know, not correct procedure.) It's like the throttle plate isn't open at all. So I know it's compensating for quite a bit when it's on there. The car is startable with it unplugged but you have to feather the gas to keep it running and it dies as soon as you let the gas go, with all electronics off of course. I should mention I have an aftermarket (Gude Performance) B-series throttle body on. Am I supposed to tighten that screw to raise the throttle maybe?

 

I'm gonna do some research and get back with results. I'm asking questions I should be able to get off my *** and answer myself lol xD

 

Just in case you're wondering where my head's at, I was wondering if my throttle body has a similar issue to this https://honda-tech.com/all-motor-naturally-aspirated-44/skunk2-70mm-throttle-body-design-problem-2919680/ I feel like that would explain why my engine wants to idle at 250-300 when warm with IACV plugged in and bogs down so low I lose power steering when stopping.

 

So I fiddled with my IACV and my throttle body today. IACV is leaking coolant, that sucks lol. Nothing was clogged. Took the idle screw completely out. No change in idle. Purposely created a large vacuum leak. No change in idle. Sounds like something is going on with my MAP sensor, huh? That would definitely make it idle like poop. I'm gonna check my vacuum routing on that since it's not factory and go from there. If that doesn't work I am going to double check the wiring. If that doesn't work I'm gonna test the map and replace it with b-series if faulty xD