The tach in my son's B16a has started jumping around while driving. Can someone give me some ideas of what to "search" for that might help with this problem? I've looked, but must not be entering enough info to find related topics. Any help is appreciated!

 

Is the tach the only problem or is it an eratic idle causing the tach to jump around.

If the tach is just eratic odds are the distrib needs to be replaced.

 

Also have an irratic idle that occurs when you start driving. If you crank the car and just let it idle, the idle is fine. After you start driving, the idle jumps up and down. This has happened before and seemed to "fix" itself, the tach problem is new. My son said someone told him the distributor was going bad. I have just replaced the main relay because the car would not start.

 

I would agree that the distributor is the most likely cause, its usually just the ignitor unit inside that makes these symptoms appear, but for the price an ignitor costs I would just replace the whole unit with a distributor king unit(he has a store on ebay) most likely the coil or bearing inside will go out soon as well so you might as well get a brand new one

 

I just went out and looked at the car and the CEL is on and the ecu is showing codes 21 and 23. Could this be part of the problem?

 

Code 21 is the Vtec solenoid.

Code 23 is the Knock sensor.

https://honda-tech.com/zerothread/1710584

I have never personally ran into the codes but look into the FAQ's

 

its not the full dizzy, swap out the igniter from and dizzy.. Also check the ground on the thermostat housing.. check for loose wires as well.. bad groungs etc..

For your Vtec selonide run new wire coming from it back to the ecu, and knock senser do the same.. I had both these problems with my crx with the same swap when i went obd1..

Is yours obd1 or 0

 

 

OBD0

 

Use this to help wire in them both sensors! Do that and get back to me, ill help from there..

-Chris

 

Thanks Chris, I had this motor running in a 91 Civic dx and swapped it into an 89 CRX Si. I guess I could have swiched some wires when I rewired the ECU. I know the knock sensor is bad- because it was broken when I did the swap.... I should have replaced it when I had the motor out! Any ideas on the tach or irratic idle problems? I haven't had time to try any suggestions offered yet, but plan on doing so Saturday. Thanks for your response Dan

 

The irratic idle can be vacume lines.. Also if your idle is set to high it will start to surge, same with low coolent.. Check all of thoes..

This video is when i had loose wires from my gay *** aftermarket tach and it was shorting out. Causing me to throw code 15 "igniter".. Lol i swaped my cluster and got ride of thoes gay white faces.

For the tach it has to do with just your igniter in your dizzy. Nuthing else in there will cause rpm to jump.. You can swap the out with any obd0 or obd1 igniter, it takes like 5min to change. If that is not the problem i would turn your key to the on position but dont have the car running. Open and slam your door, bang around the dash and any where there could be a loose connection.. If it jumps you narrowed down the location and fix it..