I've has my rtek 2.1 in my 88 t2 for quite some time now. Was running it with stock fuel system and air pump systems removed. Over the winter I upgraded fuel systems with 720cc primary and 850cc secondary injectors. Just got everything back together and now it doesn't idle the same as it used to. It seems very erratic, bounces between 700 and 900 rpm when warm. I've checked for vacuum leaks, set the tps with the rtek, tried setting the idle with the rtek. Still not happy. I did remove all of the emissions equipment, but kept the throttle body stock and kept the stock pcv system. Any ideas? Do the 720cc primary injectors effect idle quality that much?

 

have 800 cc primarys and a perfect idle.
vacuum leak..
or it could be a vacuum leak
then again a vacuum leak would do that everytime.
assuming your setting the tps right.

 

Tps is set at 20% on the Rtek with engine hot. Also checked it the mazda way with the lights and only one bulb lights. I will double check for vacuum leaks as its the only thing that makes sense at this point. I'll see if I can borrow a smoke machine from someone.

 

Well I figured out the problem tonight. Wasn't a vacuum leak. Turns out the alternator has packed it in. With the walbro fuel pump you can hear the pump whine in the car. It was idling good for a while and then it started idling crappy. When the idle changed so did the fuel pump sound. I decided to check the voltage at the battery and it was only 12v at idle. I put the battery charger on the car while running and that brought the idle right back to where it should be.

 

ah the ole no voltmeter on the cluster trick, got em.

you can view volts thru the rtek. also i dont tipically log it unless i suspect a problem.

 

Ya not having a voltmeter and the fact that the charge light never came on either both screwed me. The thought never occurred to me that charging system could have been the issue so I wasn't focused on that. I was focused on things that I had changed over the winter.

 

i warped a motor because well i was paying more attention to my gf than my dimming head lights. only realised i had no alt belt was b/c the radiator hose blew off.. live and learn.