Still diagnosing the stumble....... Now possibly fixed

jules · Postby **jules** » Sat Feb 23, 2008 10:59 am

And she is a terrible tart I have to say!

Jules

ampz · Postby **ampz** » Sat Feb 23, 2008 11:25 am

my AFRs went bezerk when i put in the AFM upside down fwiw.

It's a different world now without it ;)

Boags · Postby **Boags** » Sat Mar 08, 2008 9:36 pm

jules wrote:
Uncle Arthur wrote:Turn the clock back to October 07 when Jules had the car........ a hot day, and hard driving, up Springbrook

Ummm.. it might not have been just "that" run up Springbrook when I had Max

Glad to hear it's fixed though! Next question, Boags has a stumble. Is he using an RX-7 AFM too?

Jules

My stumble is not over bumps... My stumble is most definately caused by me being too cheap to spend money on DYNO time yet. It is poor tune for sure.

Boags

Boags · Postby **Boags** » Sat Mar 08, 2008 9:54 pm

jules wrote:And she is a terrible tart I have to say!

Jules

She is too; you should have heard the things she whispered in my ear on the way to dodgy day that time... I'd repeat but children would cry. :shock:

jules · Postby **jules** » Sun Mar 09, 2008 11:25 am

Great to have you back Boags!

Jules

Boags · Postby **Boags** » Sun Mar 09, 2008 12:06 pm

jules wrote:Great to have you back Boags!

Jules

Group hug!

Boags · Postby **Boags** » Mon Mar 24, 2008 7:43 pm

Boags'MX5 wrote:My stumble is not over bumps... My stumble is most definately caused by me being too cheap to spend money on DYNO time yet. It is poor tune for sure.

Boags

Yes, bad tune was the culprit. The bad tune was supplied by an "autotune" for the eManage. It is reported to work very well when upgrading from stock injectors to 1.8L injectors, but I found with the bigger injectors that I'm running (305cc) there isn't enough control and the stumbles result from rich spikes.

I spent a few hundred $$$ and got a wideband O2 sensor from the US; then spent good Friday installing it and the guage. I could see immediately that the whole system was very rich under boost, but inconsistently. I remeved the autotune and narrowband O2 sensor from the ECU and adjusted the injector correction in the emanage to make sure the engine didn't run lean. The engine ran off the open loop maps from the stock ECU and kept nicely rich (between 12.5 and 10:1). I went down to UA's place today and he helped me out with some maps and tuning and we got the car running smoothly... Hey presto; no stumbles.

I monitored it very closely on the way home and there aren't any lean spots and the air/fuel ratio glides smoothly towards rich as I increase boost. It is still too rich at full noise (10:1), but I think I'll solve that with a few more PSI... :twisted:

Big thanks to UA; and as I said in another thread; the whole process would have been cheaper and not taken as long if I'd spent a few more $$$ in the firstplace. :roll:

Boags (very happy). :mrgreen:

NMX516 · Postby **NMX516** » Mon Mar 24, 2008 7:47 pm

Ah glad to hear you got it sorted Boags! I still haven't had the chance to sit down and play with Virtual PC :roll:

Boags · Postby **Boags** » Mon Mar 24, 2008 7:49 pm

NMX516 wrote:Ah glad to hear you got it sorted Boags! I still haven't had the chance to sit down and play with Virtual PC

No probs. I forgot to thank you in my spiel; for coming out and trying to help a forumite in need!

You're a top bloke and it's great having you so close by.

Boags

Uncle Arthur · Postby **Uncle Arthur** » Mon Mar 24, 2008 10:23 pm

Boags'MX5 wrote:
Boags'MX5 wrote:My stumble is not over bumps... My stumble is most definately caused by me being too cheap to spend money on DYNO time yet. It is poor tune for sure.

Boags

I found with the bigger injectors that I'm running (305cc) there isn't enough control and the stumbles result from rich spikes.

Big thanks to UA; and as I said in another thread; the whole process would have been cheaper and not taken as long if I'd spent a few more $$$ in the firstplace.

You're (we're) gonna need to rejig the injector correction then - we set it to 275cc not 305cc.

And my pleasure to help

NMX516 · Postby **NMX516** » Tue Mar 25, 2008 9:04 am

Boags'MX5 wrote:
NMX516 wrote:Ah glad to hear you got it sorted Boags! I still haven't had the chance to sit down and play with Virtual PC

No probs. I forgot to thank you in my spiel; for coming out and trying to help a forumite in need!

You're a top bloke and it's great having you so close by.

Boags

Aw shucks

No worries mate, always happy to at least try and help out

Boags · Postby **Boags** » Tue Mar 25, 2008 11:50 am

Uncle Arthur wrote:You're (we're) gonna need to rejig the injector correction then - we set it to 275cc not 305cc.

And my pleasure to help

No we're not; eManage isn;t as good as it should be. :wink:

It idles at ~14.7, that is what's important for injector correction. Anything else the dyno tuner can figure out... :mrgreen:

Uncle Arthur · Postby **Uncle Arthur** » Tue Mar 25, 2008 12:19 pm

Well - we can always just pull fuel in the upper part of the map.

Do you want to check where it comes on really rich, both in terms of boost and revs, and I'll pull some numbers out of your base tune (which I have here) and then I'll email it to you, or you can come round and I'll reload it.

Boags · Postby **Boags** » Tue Mar 25, 2008 2:17 pm

Sounds good, I'll up ze boooost and then check where there is too much fuel... I'll let you know then come round for another tune up. When are we going on the dyno?

Uncle Arthur · Postby **Uncle Arthur** » Tue Mar 25, 2008 3:07 pm

Boags'MX5 wrote:Sounds good, I'll up ze boooost and then check where there is too much fuel... I'll let you know then come round for another tune up. When are we going on the dyno?

When I can afford it