Strange behavior at full boost

Oggers

Oggers

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Good evening all,

Having a little trouble with my truck need some help

It's a Paxton truck with a full Torrie sct tune and parts

When I'm at the top end of the rev range (about 4.5-5k) in 4th and 5th gear it will suddenly go very rich and bog down a/f hits about 8.5
6446064d901adc340b649c118ab36922.jpg

It's a lot more obvious in this one where the cursor is
f4f7bf8767f356700fda1d33179e4333.jpg


I'm ruling out belt slip because boost is still good.

Any thought?

Charles
 
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Is the tune, a base tune that he sent you? or is it one that he did on a dyno for you?
 
Santeen? Do my eyes deceive me?
 
We need more info. Has it been like this or just start? Did you change anything? What fuel set up you running? Once it does this if you immediately slow down and gear down and go again does it act normal again tell the same gear?
 
Charles,

Looks like you did the Paxton split second box delete?
If so, did it have the same behavior with the stock set up eg split second box, twin pumps etc?
Seems a little odd that it's over fueling in higher gears? I'd have thought the behavior should be the same thoughout as I'd suspect the fuel table is the same no matter what gear?
I did wonder about clutch slip in higher gears - so power requirement would drop momentarily (assuming an rc) but it looks like the engine speed is climbing normally?

Neil
 
the two things I see are a flat MAP signal and rich 02 readings happening in 4th gear. Fuel tables don't know what gear you are in and I highly doubt that vehicle speed would be an adjustment variable for the fuel tables. It's hard to tell if the flat MAP signal is the root cause or whatever causing the rich condition is affecting the MAP signal. Can you log any other parameters? Logging fuel trims or ignition timing might be a good start. Any other recent mods or changes? Are you getting any codes?
 
bmxam962 said:
We need more info. Has it been like this or just start? Did you change anything? What fuel set up you running? Once it does this if you immediately slow down and gear down and go again does it act normal again tell the same gear?
Click to expand...

This was the first run after installing everything

Walbro
69lb injectors
2bar map
Sct

I will try the gear down and pull again, 1st-3rd seem to pull normally it just the bigger gears that's giving me trouble.
 
Neil said:
Charles,

Looks like you did the Paxton split second box delete?
If so, did it have the same behavior with the stock set up eg split second box, twin pumps etc?
Seems a little odd that it's over fueling in higher gears? I'd have thought the behavior should be the same thoughout as I'd suspect the fuel table is the same no matter what gear?
I did wonder about clutch slip in higher gears - so power requirement would drop momentarily (assuming an rc) but it looks like the engine speed is climbing normally?

Neil
Click to expand...

Correct split second is gone along with helper pumps and all the other bits bolted to the frame.

it just ran normally with the split second on it, I just wanted something a bit safer that could be adjusted that's why I went for the sct..

Don't think it's clutch slip as revs don't rise. It just bogs and won't pull through.
 
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seethrough said:
the two things I see are a flat MAP signal and rich 02 readings happening in 4th gear. Fuel tables don't know what gear you are in and I highly doubt that vehicle speed would be an adjustment variable for the fuel tables. It's hard to tell if the flat MAP signal is the root cause or whatever causing the rich condition is affecting the MAP signal. Can you log any other parameters? Logging fuel trims or ignition timing might be a good start. Any other recent mods or changes? Are you getting any codes?
Click to expand...

I can only log a/f and boost from the aem gauge.
No engine codes
This was the first run after installing all the bits from Torrie.
 
Thank you for all the input people, I'm possibly the only one in the uk with this setup so it's very difficult/impossible to find someone that knows what I'm talking about. So all your information/ideas/problem solving is a great help.

Charlie
 
Last edited:
Oggers said:
This is the first base tune that he sent me. Not been on the dyno yet
Click to expand...

Well there's ur answer. get with Torrie. Get it on a dyno and email him the data while its on the dyno. He'll get it sorted out
 
Now that were talking about not acting normal mine 10 is kind of the same way but its on low rpms doesn't have a good response at all till like about 3k a/f is where is always has been SCT tune, paxton can anybody help me out ?
 
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