1999 DIYPNP IDLE VALVE ISSUE
#1
Junior Member
Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
1999 DIYPNP idle valve issue (now with MSQ)
I am having a hard time getting the idle valve to function. I have gone through all the Mega Miata blog posts and the information here on this site. I was able to get the idle valve to function correctly in the previous 3 DIYPNP's that I have built, one for my racecar and two for friends, but this one has got me stumped. I will post up my msq later this afternoon, when I have access to my tuning laptop. Basically, when I have the idle valve set to 480hz, and I do the idle valve test, I am getting little to no action until I get very high in the duty cycle. From 0-40 there is no change, from 41-75 there is a 10-20rpm change and from 76-88 the rpms go up as expected, but from 88-99 there is a LARGE jump, like from 1500 to 4000rpms. Also, when I start the car, the idle valve does not run and fast idle for a brief moment like it does on all the other installs I have done. I am thinking it may be the idle valve itself as it has 190,000 miles on it, but I want to make sure it is not a simple setting I am missing. I have tried to run the idle valve inverted as well and I get similar behavior in the test mode, but the numbers are reversed in 100% gives no valve action and 0% is fully open. Also, no matter what frequency I put, the valve makes noise.
Thanks for any suggestions and I will get my MSQ posted up this afternoon.
Thanks for any suggestions and I will get my MSQ posted up this afternoon.
Last edited by MX5RACER; 01-23-2017 at 06:03 PM.
#3
Junior Member
Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
Diode is installed and I do not have any higher frequency to chose from other than 480hz. Is there another firmware that can get me there or is there a script change needed via the notepad edit of the MSQ file?
#4
Junior Member
Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
Here is my most recent MSQ file. I did some playing this afternoon with voltage compensation idle values and did not get much results. Please take a look and tell me what little setting I am missing!
Thanks for your help.
2017-01-23_17.57.37.msq
Idle valve changes 2017-01-20_17.53.55.msq
Thanks for your help.
2017-01-23_17.57.37.msq
Idle valve changes 2017-01-20_17.53.55.msq
#6
Junior Member
Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
I am getting little to no action of the idle valve. I have to hold the revs up first thing in the morning until a little warm and then it will maintain its own idle. What spefically would you like to see in the log? Cold or hot, a rev and return to idle a few times?
Thanks for the help.
Thanks for the help.
#9
Junior Member
Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
Here is a log of an idle valve test from 100 to 0, please see attached.
Idle valve test 2017-01-24_17.39.29.msl
Idle valve test 2017-01-24_17.39.29.msl
#11
Junior Member
Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
A lower frequency will cause the valve to make more noise, but lowers the range at which the valve responds within test mode, but I still get no idle increase even with the new values from the test mode entered.
When I get home this evening, I will remove the DIYPNP and open up the case and report back with the findings.
When I get home this evening, I will remove the DIYPNP and open up the case and report back with the findings.
#15
Junior Member
Thread Starter
Join Date: Dec 2008
Location: Ft. Lauderdale, FL
Posts: 315
Total Cats: 9
Ok, update time! Lesson for the day... When you guy second hand devices do NOT assume the previous owner assembled the device correctly. I opened up the unit and there is no diode. In its place there is a resistor to 5v. I de-soldered the resistor and soldered in a diode I had from other Megasquirt builds. Put the unit back in the car and I now have a normally functioning idle valve! Thanks for all who helped.