hello everyone. I bought this car from a buddy of mine as a project car we knew it had a blown head gasket. It's a 93 civic ex 4 door with a D16z6 swap with high compression pistons. After replacing the head gasket head studs plugs wires and injectors it started up and ran on all 4 just one problem. When it started up cold it idles at 3000 rpm's. there is no fluctuation in the idle its just rediculiously high. After it warms up it will idle down to 1500-1600 rpm's which is still too high. The tps is working correctly and the throttle is not cracked open all. Could this be because a dirty iacv? Also is there anything else I should clean/ check.

 

Did you try to use a flathead and adjust the idle manually?
Should be located near the throttle body.

 

for the love of god please update us when you figure it out haha. i got a 93 civic dx that idles high cold and then when warm it goes down some but then it will bounce up and down and up and down. and also when the car warms up it runs like ****. everytime i give it gas it kinda boggs out and has hardly any power. had a mechanic look at it and he said try a new ecu so i did that and the idle still bounces and the car still runs like **** when its warm. so please let me know when you find out what your idle problem is. i have cleaned my fit valve. replaces iacv and have all new coil pack, rotor, dizzy cap, wires, and plugs. and ecm. no clue what my problem is.

 

Yes, this and if there is a small vaccumm leak, it might cause this too. But normally those leaks, cause fluctuations. Sounds like u just need to adjust the tb set screw.

 

fitv adjustment or vacuum leak. Adjusting the base idle is not the way to fix it.
http://www.preterhuman.net/texts/aut...a_CRX/FITV.pdf

 

You should check your fuel filter

 

Clean adjust the FITV and also make sure that the throttle cable is not adjusted too tightly - there should be some slack.

 

Did the cleaning it work? I'm having the same problem.

 

first off an ex is not 4 door its 2 door with a sun roof and they came stock with the d16z6 the ex ones the 4 doors came stock with a d15 anyways my 93 ex does this at cold start up 3k but it goes down to about 1k at idle warm or 1100 but anyways i would start with the iacv sounds like its sticking open and check vac lines u can do this with some carb cleaner just spray around the lines and if the motor changes in sound or cuts out u know where its leakin

 

oh one more thing check the distributor timing this can affect idle 2 as it also controls injector timing

 

ok i changed my fuel filter. runs a little bit better but still has hardly any power when accelerating and kind of bogs out. any other ideas?

 

Yes, fitv

 

Please research...you dont know what your are talking about. There are 3 trims for the 4 door. ex (d16z6) dx (d15b7) lx (d15b7) and all 92-95 civic ex whether its a 2 or 4 door came standard with the d16z6.


OP...is the tps calibrated? Besides that I would check that the idle is adjusted properly, and that the FITV is clean and in working order.

 

I sorta have the some problem but my IDLE sometimes goes to like 2000rpm while on the road and it cause my shifting to only catch the clutch in high rpms its terrible idk whats wrong.

 

If I unplug the electrical connector to the IACV, engine speed bounces like that because (obviously) the ECU can no longer make adjustments via the IACV. The ECU is apparently adjusting "something else" that causes the bouncing.

So make sure your IACV is actually getting a signal back from the ECU. Unplug the connector while the car is running and check the pins with a voltmeter to see if it is dead or not. Also, if you plug and unplug the connector and nothing about the idle changes, then maybe a break in the wire somewhere between the ECU and the IACV?