New owner w/a dohc ZC: uneven hi idle & erratic rpm gauge

[89ZCteg]

Hey guys, new owner here needing help.

I just bought a 89 Integra w/a dohc ZC w/ a DC CARB header. I have 2 issues right now: uneven hi idle (1400ish rpm & intermittent erratic tachometer).
I replaced: IACV, fuel filter, thermostat, PCV. I also had had the TB & throttle cable checked. I just reset the ECU.
The mechanic figured out that if one of the vacuum hoses (the left most of the 3 coming out the of the TB) are pinched shut, the idle drops to normal.

Am I having vacuum issues only or is this something to do with one of the 3 black valves (purge valve & dashpot) located on the firewall?

I've read somewhere the erratic rpm gauge might be distributor related: is the uneven high idle somehow related to the erratic rpm gauge?

Please help! I've searched all over and can't figure this out.

 

[enoch723]

Most the time irratic idle is from a vacuum leak. And the d16a1 has a lot of problems with the dashpot. I would just delete it.. cause it isnt needed.

Find the vacuum leaks with a cigar or something. Blow smoke everywhere and if it doesnt drop in idle then you dont have any leaks

 

[89ZCteg]

Enoch,

thanks 4 your reply, its the most helpful advice I've gotten to date.

When you mean to delete the dashpots (theres 3 of them), do you mean bypass them or simply plug or remove the lines.

thanks again!

 

[enoch723]

I just took all of them off conpletly and plugged off outlets from the manifold. Im one of those people that follow the rule of that the less that could go wrong, then less will go wrong.

 

[89ZCteg]

I have 3 outlets from the top of the manifold. Didn't know they were not critical. Who knew.

thanks again. I'll try this out.

 

[enoch723]

Yeah vacuum lines arent exactly critical if there isnt some kind of sensor on it. As long as the lines arent leaking its fine. With the dashpot its fine cause all the dashpot really does is return the throttle back to normal. I removed mine already

 

[89ZCteg]

Im gonna try & remove as many lines as possible!!