Idle Surge with Hydra Install - Desperate for help
 

All,

I have been trying to install a Hydra (v2.17) on my '01 for longer than I care to admit and have not been able to resolve an idle surge issue. It sounds like a vacuum leak, but I sprayed carb cleaner around the RC 550cc injectors and there is no change in idle.
I put the stock injectors back in, connected the stock ECU and the car idles fine, which would indicate to me if it is a vacuum leak, it would have to be at the injectors. I have pulled and reseated the 550cc injectors numerours times with the same result. I also replaced the insulators with OEM, as well as the insulators Stephanie and Apexonyou recommended in this thread from a couple of weeks ago.

I found this thread about Revs oscillating, but I don't think that is my issue as last fall, Jeremy checked the default map I'm using.

Here is a crappy video of the surge sound. I should note, I am at the point in the install where you first start the car and set the timing. I have done no tuning as of yet.

A similar problem happened to me when I installed my turbo kit. I had removed the throttle body and when I reattached it, the throttle cable was too tight and the throttle was pulled partially open. It sounded similar to what yours sounds like.

I have to idle pretty rich-- like 13.7 with my 750cc injectors. Perhaps try enrichening your idle cells dramatically.

I updated the thread you linked to. For that problem, I was running lean because my wideband had died.


I would check the throttle cable first, then calibrate the throttle positioning sensor, then try enrichening, then mess with the ISC settings. My settings had to be pretty far from the base settings to idle properly. Try setting it to zero for the max and min and see what it does. Mine is set to 5/40 or something like that..

The stock ECU may just respond to the "error condition" more happily than the hydra so that may be misleading. Good luck!

I agree, My idle fluctuates with the A/C on. I tried to correct it by setting the idle screw on the TB. When I turned it up the fluctuation continued and increased in frequency and sounded like your video. I am not telling you that decreasing the idle screw will fix it but it should get you closer to the fix.

I resolved this a few weeks ago. Turns out it was an issue with the VVT adjustment. I found the solution on M.net in an old thread by Y8s.

I'm digging for it now. Any key word or a link?

Here is a link to the thread. Post #8 is where it talks about the surge problem.

Thanks