I have 750cc injectors and hondata 2b. The car drives impeccable except for one thing, once I let off the throttle from higher than 3000 rpm, the rpm drops to like 200 rpm and then catches itself back up to 800 rpm. Sometimes the car stalls but most of the time it catches itself. What can I do?

 

My car does the samething with my hondata and 440cc's. Im not sure how to stop this But would also like to know....Better tunning maybe?

 

Count me in as wanting to know, my car does this with 450s and i'm not even running a hondata, i have an e6k.

 

ive got the same problem here, ive got 440's. It hasnt stalled since a retune, but it still goes pretty low.

 

i have the same exact problem...it doesnt do it all the time, but rarely..

 

I have the 2B with 720s and no off idle or return to idle problems. Might just be the amount of time tuning. I spent $400 in dyno tune time alone once the system was installed, so I was sure it was done right.

 

i have the same problem with 750cc's and hondata 3b. kinda sux but oh well

 

My personal fix with my E6K was to raise the cut off point for fuel cut in decel. It started out at 1200, its now at 2000 to stop that problem. It's my personal opinion, that because most large injectors take near 1 ms to open, that extra 1ms is allowing the engine to get to low enough an idle speed to almost die when in fuel cut decel. I'm sure setting up the idle speed might help a little.

 

I have the same thing with 550's. Kind of dangerous sometimes.

 

thanks, good place to start

 

mine does that only when its stuck in open loop. when it is in closed loop it idles as perfect as stock. sounds like u could just use some more tuning at idle with wideband/.

whoops noticed its a decel problem hehe. sorry, i was describing a similar idle. but then again its probably nothing a lil dyno time cant fix haha.


[Modified by DIRep972, 4:08 AM 10/14/2002]

 

i have the 4b and 720cc injectors. idles like stock with no hesistations, everyone is right... you need a little more tuning to fix this and youll be good to go.

 

Anyone using the S200 yet? I had this same issue with my 2b and 550cc injectors, but it's gone now. Same map burned to a chip with the new romeditor and no more dipping issues. I guess it could've been a bad chip, burn, or some other reason (on the 2b), but so far so good with the new unit.

 

I have the same problem. but since i got it tuned it is not nearly as bad, and only drops around 100 rpms and idles around 600 rpms. maybe a tuning issue.

-deepsi

 

I might have the key to all your problems. Look at the throttle body. There should be a flat head screw on there. I believe this this call the throttle body inlet screw. Allow your car to come to normal temperature. Adjust this screw so that more air can be release. Adjust yout idle RPM to about 800 or whatever is the best case for you.

Hope this works! :D

 

The injectors are not your problem. You just need to tune your idle properly. Follow the instructions:

http://www.hondaprelude.to/hitman-bac.html

You also need to play with the fuel map around the idle points alot. It has to be pretty flat. I found my car likes to idle pretty lean, around 14:1 for a stable idle.

It took me a little while to get a good idle. I get no dipping or surging at all and I get good hot and cold starts with 550cc injectors.

 

I have already done this, dont work, the problem is that sometime the idle jumps and falls so the car almost stalls, It does not care what the idle is set at....

 

In that case then it sounds like a tuning issue. Could be something else that went bad.

Good luck.

 

For some reason mine seems to want to idle a little on the rich side, may be the manifold design and huge throttle body, not sure yet.

 

sometimes my car randomly goes into open loop at idle. the idle will flucuate and the car almost feels like it wants to die. all i do is turn it off and then back on again and its back in closed loop. wierd

 

What you said earlier, Jared, about raising fuel cut off for decel sounds good.
If i let off the accel at anything less than 2000 rpm it doesnt drop past idle, it catches itself right at idle or near and doesnt go lower.

If I let off the accel at anything over 3000 rpm then i experience the drop. Im thinking an rpm decel from over 3000 rpm must be too fast for injectors to adjust back to idle in time if cut off point is too low. I hope this feature on the hondata is adjustable.

 

No problems here either. I'm running 550's and raised my idle to 900. Only time it does it if I'm driving around in open loop, or sometimes when I have the a/c on it drops a little low. Like everyone else said, sounds like you just have to tune it a little better around idle.

-Mike

 

My Talon does this too. Boost to 17.5.. hits full boost by 33-3400 let off and it stumbles around 200rpm then catches.
Hmm.. I think the ecu is still dumping fuel and not reacting quick enough... Or It may just be excess fuel pressure (in the lines) coming out when you let off from +boost to vac.. because your fuel is increasing with boost obviously.. the injectors might be letting the extra fuel off causing a stumble... I dunno its a shot in the dark.