Ok. I'm borrowing a board member's P28 by Kenji. So I know it works just fine, must be my car...

Here's the story...
With my stock ecu, my idle is often around 1000-1100. Idle seems to 'slowly' (i.e., VERY slowly) move itself down towards 750 after being on the highway or kept at a certain rpm for a length of time.

I put the P28 in today, and started up the car. Same old, so I thought. I blipped the throttle a few times before backing out of the driveway. I stopped to clean up a few things in the garage and let the car idle. Vroom (up), vroom (down), over and over. RPM is going from 750 to 1750 like clockwork. I've read a million times on h-t about that. I drive around the block and it continues. I then get on to a few main roads and open it up a big. Nice difference from the stock ecu in the midrange.

I pull back in the garage, no idle problem, dead on 750rpms. The car was warmed up the entire time, so I don't suspect that the idle hunting has anything to do with being cold.

Anyone have any ideas? I'm stumped. I'm worried this is a sign that something (tps, iacv, something else) is not quite right under my hood, something that oddly enough my stock ecu obviously doesn't care about.

 

Chris - I've never had the problem with the ECU.

Did you disconnect the battery when you swapped out the ECU?

Also, did you let the car run with the ECU for several minutes without tapping the throttle?

 

Yea, this all happened AFTER letting the car sit and idle. Battery was disconnected, etc. Maybe i'll go try again and let it sit for a few minutes longer.

Like I said, I KNOW it isn't the ecu, since you had no problems with it at all. Just thinking it was an indicator that something was odd with my car.

 

From Sean, from a post in a thread by Raging Angel:

does anyone else have this problem, and should i not be concerned about it happening on my car, but not others who have used this very same ecu??

I'm going to do a little more playing around to see if the idle hunting persists and find the big vacuum hose and do some pinching.


[Modified by 1107, 6:36 PM 11/21/2002]

 

Foo, try driving 4mins below 3500 rpm. Then check, I bet it stay at 750-800rpm.
Most likely you warmup the car improperly.

 

the Kenji ecu's do not read all of the sensors of the stock ecu's so a bit of a idle problem occurs once the car is warm its fine.

 

My kenji p28 idles fine for mine. 800~

It only idles at 800 when it's warmed up though..

 

What sensors exactly does Kenji's ECU disregard?

As for the question, the p28 on my car has a slight fluctuation during cold starts but not as drastic as what you're experiencing. Mine goes from 1350 to ~1225 approx 5 times but once warm, it fluctuates from 735 to 755 according to the VAFC.

 

I had a same problem. I just disconneted the EVAP connetor near the firewall.

 

No worries. Thanks for the info. I just wanted to be sure that it wasn't something with MY car/engine, since i knew it wasn't some ecu error.

After driving around tonight, it went away. DIdn't really come back, and nothing i couldn't get used to if this ecu was here to stay.

 

George,

You took the words right out of my mouth . Thanks for posting that info for me.


A few cars may experience idle issues. These can easily be fixed and I provide technical support to all of my customers (and just about anybody else). If you are experiencing issues with any of my products please let me know so I can tell you how to correct them.

The idle adjustment screw will fix low idle and surging idle conditions.

The quote above will fix hard start-up conditions on all cars that have an OBD2 to OBD1 ECU conversion harness. This applies to ALL OBD2 to OBD1 ECU conversion harnesses, not just mine.

If anybody has any questions please ask.

I want to take this opportunity to thank all of the people who purchased ECUs and harnesses from me. I also want to thank all of you for the kind words and support on this board regarding my products.

I do virtually no advertising. All of my business over the years have come from word of mouth and without you guys I would not be where I am now. Thank you all.

-kenji

 

Thanks Kenji.

Again, just so I'm clear, I never thought this was a 'defect' in Kenji's ecu/harness. Just concerned about a sensor or something being bad in my car. Now that I know what the real problem is.... thanks, no big deal.

By the way, on the ecu and harness.

 

Kenji's ECU works for me. No Probs.

 

Where's that? About to retire from selling harnesses? j/k

 

I have the same problem with my car using Hondata Stage II and a P28 ECU.

I'm going to see if this "fix" helps my car too.

BPR

 

I hope my P28 and Hondata stage 2 didn't have this problem, if not, I will have to save this thread!!

 

That might explain why it's har to start the car at times...

 

I was having this problem with my hatch, I have a OBD2 B16A2 from a 99 SI and a Skunk2 ecu and conversion harness. I was getting a hunting Idle after my car would warm up but It would only go away after a month or so and playing with the idle screw. Then every time I disconnect the battery it would reset the ECU and I'd be back to square one.

After reading this I disconnected my EVAP sensor and the idle is steady. But my problem is now, that the weather is very cold, the engine wants to stall out when starting my car in the morning. I have to keep my foot on the gas on until the car warms up, but once warm it's fine. Any thoughts?

 

i am having the same prolem with my p28 i dont have the evap hooked up but i still get the hunting idle what to do what could be wrong???

 

Maybe you need a new Throttle Position Sensor (TPS). IF you have unplugged the evap solenoid and still have hunting idle, i'd say that is your problem, TPS.

 

OT: ............. Chris N ........... what the hell did you do wrong to get the Eye of Sauron on you!!

 

Ha! The eye of sauron sees all!!! mwhahaha!!!!

OT: I tried to grab a better pic of the Eye from the DVD I have, tried to use the printscreen program I have, but it was doing some odd things, so I had to settle for this eye.

 

LOTR rules ......... just got the extended DVD, halfway through it last night before wife started falling asleep and we went to bed ........

Sorry ....... no thread hyjacking .....

 

Tell me about it. His Im screen pops up and i see the eye first. ahahha
cool avatar, Chris.

 

for starters the tps is brand new from the spoon throttle body but the hunting idle has stopped do to the test pipe i put on could it be that there was to much back pressure ???