Multiport EFI on a 66 Triumph TR4a. It idles nicely, but to pull out from a stop you have to gradually increase the throttle to get the revs up, then it has pretty good power but only for about 1/4 to 1/3 throttle. Push the gas any more than that and it stumbles badly. Let up on the gas and ease it down and the power comes back on. I have tried adjusting the fuel map but can't seem to make a difference. What could be causing this and how do I fix it?
Thanks
Dan B
Stumbling under WOT but idles great
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Re: Stumbling under WOT but idles great
Possibly this is more tied to the ignition map. I have tweaked it some after talking to Jim Blackwood, but right now I can't get TS to connect to my controller. It cannot recognize the signature. It says my controller has * version. It should be 2.3....
Re: Stumbling under WOT but idles great
IMHO, the ignition map would have to be miles out to cause a stumble. Far more likely to be mixture too weak. Have you got a wideband O2 sensor fitted? This should show up the problem instantly.
Dave P, London UK.
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
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Matt Cramer
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Re: Stumbling under WOT but idles great
Please post a data log of the problem and a copy of your MSQ file.
Re: Stumbling under WOT but idles great
The datalog from Sunday's drive.
The tune.
Thanks!
The tune.
Thanks!
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Re: Stumbling under WOT but idles great
Over a year later? 
Dave P, London UK.
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
-
Matt Cramer
- Super Squirter
- Posts: 2951
- Joined: Sat Jul 03, 2004 11:35 am
Re: Stumbling under WOT but idles great
Your AE is triggering way too easily; try increasing the TPSDot threshold to 75%/sec.
What sort of O2 sensor are you using, and what calibration data?
What sort of O2 sensor are you using, and what calibration data?
Re: Stumbling under WOT but idles great
I'll try that. I'm using an LC-1. Not sure what you mean by calibration data. I did recalibrate the sensor in fresh air following Innovate's instructions. Am I missing something in TunerStudio?
Re: Stumbling under WOT but idles great
Yes, Dave, I had to pull the engine and change the bearings over the winter. Just now getting back to tuning. 
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Matt Cramer
- Super Squirter
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- Joined: Sat Jul 03, 2004 11:35 am
Re: Stumbling under WOT but idles great
It's under Tools -> Calibrate AFR Table. Please re-send the LC-1 default settings. It seems you are using a different calibration as some of the readings in the data log are out of the range a standard LC-1 calibration will supply.DanB wrote:Am I missing something in TunerStudio?
Re: Stumbling under WOT but idles great
I played with it some this weekend after brother Jim helped me tweak the tables a couple of weeks before. I have not done the software calibration yet. Perhaps that will make a difference. Here is the data log from Sunday.