Rough Idle and Hesitation

pebbles22 · Postby **pebbles22** » Fri Apr 26, 2013 11:45 pm

Hey, i just recently purchased a 1990 Mazda MX5 NA6, it already has an aftermarket ecu and an mx5 mania enlarged air intake. However im finding when i start on cold or when its warmed that my idle fluctuates between 400rpm to 1000rpm. Also if im downshifting into 3rd or 2nd my revs go so low that the car stalls. Im also finding that when i accelerate there is a delay then it starts accelerating.

Im new to modern style cars so if anyone could point me in the right direction that would be greatly appreciated.

thanks

Postby **NitroDann** » Fri Apr 26, 2013 11:51 pm

98% chance it needs a tune, the past tuner didnt put a lot of effort into the idle. A common place the tuner doesnt get right.

Dann

pebbles22 · Postby **pebbles22** » Sat Apr 27, 2013 1:52 am

how much would a decent tune set me back?

project.r.racing · Postby **project.r.racing** » Sat Apr 27, 2013 10:31 am

Sorry I cannot help you with your situation, I just found this ammusing.

pebbles22 wrote:Hey, i just recently purchased a 1990 Mazda MX5 NA6, ... Im new to modern style cars so if anyone could point me in the right direction that would be greatly appreciated.

Not sure if I'd call a 23yo car modern.

p.s. Welcome to the community. :beer:

pebbles22 · Postby **pebbles22** » Wed May 01, 2013 1:02 am

i came from a 70's car though, btw problem is fixed.

ausbuoy · Postby **ausbuoy** » Wed May 01, 2013 5:39 am

How so?

pebbles22 · Postby **pebbles22** » Wed May 01, 2013 2:34 pm

The previous mechanic who installed the aftermarket ECU used the vacuum line which goes to the cruise control as MAP sensor. So i uninstalled the charcoal canister and used the vacuum line to the purge control to go to the ECU instead. Now the car runs very nice.

93_Clubman · Postby **93_Clubman** » Sat May 04, 2013 1:06 pm

pebbles22 wrote:The previous mechanic who installed the aftermarket ECU used the vacuum line which goes to the cruise control as MAP sensor. So i uninstalled the charcoal canister and used the vacuum line to the purge control to go to the ECU instead. Now the car runs very nice.

Welcome, congrats & well done!