Stalling issue on somebody's tune. Bypass valve questions

[stewarts2008]

I got my car dyno tuned here by a local guy and it works great. That isnt the issue.

My issue is that with somebody elses tune that I got in a deal, my car isnt tuning as normally as every body elses. Why am I still bothering with it if i have a tune that works great, you ask? IDK. I just am. Here is whats going on.

With this email tune, I get compressor surge if i rev it high or do a pull. It also wants to die everytime I cruise to a stop. Sometimes it comes to a stop perfectly fine, other times the RPMs drop, goes rich, and dies. WOT is spot on though.

I spent entire days going back over the i/c piping as well as taking everything apart to include throttle body, boss intake mani, throttle body spacer... and i check to make sure they are seated properly. I even tried the debated method of spraying carb cleaner on the connections to see if the idle raises due to a leak. So that should eliminate boost and vacuum leaks.

My dyno tune sometimes goes a LITTLE rich on decel/coming to a stop, but it never thinks of stalling.

That leaves the Bypass valve. This is my latest theory. If i had a bypass that doenst compressor surge with my dyno tune, but does it on this other email tune, I could assume that the dyno tune guy has the cam positions set up more aggressively and it creates a larger vacuum to open the BPV. Now, in theory, if I thought my BPV was too tight, I would loosen it and that would resolve the fluttering of the other tune because it would take less vacuum to open the valve, right?

I have also been reading that faulty BPVs could lead to that stalling/rich condition on decel as well. Is that correct?


Any input is appreciated. Thanks for your help.

 

[Blazer707@TBR]

I got my car dyno tuned here by a local guy and it works great. That isnt the issue.

My issue is that with somebody elses tune that I got in a deal, my car isnt tuning as normally as every body elses. Why am I still bothering with it if i have a tune that works great, you ask? IDK. I just am. Here is whats going on.

With this email tune, I get compressor surge if i rev it high or do a pull. It also wants to die everytime I cruise to a stop. Sometimes it comes to a stop perfectly fine, other times the RPMs drop, goes rich, and dies. WOT is spot on though.

I spent entire days going back over the i/c piping as well as taking everything apart to include throttle body, boss intake mani, throttle body spacer... and i check to make sure they are seated properly. I even tried the debated method of spraying carb cleaner on the connections to see if the idle raises due to a leak. So that should eliminate boost and vacuum leaks.

My dyno tune sometimes goes a LITTLE rich on decel/coming to a stop, but it never thinks of stalling.

That leaves the Bypass valve. This is my latest theory. If i had a bypass that doenst compressor surge with my dyno tune, but does it on this other email tune, I could assume that the dyno tune guy has the cam positions set up more aggressively and it creates a larger vacuum to open the BPV. Now, in theory, if I thought my BPV was too tight, I would loosen it and that would resolve the fluttering of the other tune because it would take less vacuum to open the valve, right?

I have also been reading that faulty BPVs could lead to that stalling/rich condition on decel as well. Is that correct?


Any input is appreciated. Thanks for your help.

Have you asked beefcake for any help? He knows alot about these kits and also can get into contact with lund easier if its a tune concern.

-Thomas

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

 

[stewarts2008]

Have you asked beefcake for any help? He knows alot about these kits and also can get into contact with lund easier if its a tune concern.

-Thomas

Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

we have spoken, but we havent been able to come up with anything solid between all of us. Not sure is TPS would be an issue, but its hard to know why one tune works vs somebody who does this tune all of the time.

 

[bam2012@TBR]

Sorry to hear you are having issues. My lund tune has gotten better every revision. I would get with lund and remote tune your car on the dyno if you are having issues with it. I might remote tune later on when the 8.5 lbs gets boring.

 

[stang8psi]

my Lund tune stalled everytime the clutch was engaged and if you put in nuetral..

 

[stewarts2008]

my Lund tune stalled everytime the clutch was engaged and if you put in nuetral..

yea, if i try to coast to a stop in neutral, it stalls on that tune

 

[bam2012@TBR]

yea, if i try to coast to a stop in neutral, it stalls on that tune

Wow, how many revisons have you gone thru with lund? Including my gear swap I have had five, and even the base tune had zero of the issues that you have had. Sorry to hear about your issues, I'm sure that ken and Jon can get you fixed up if given the chance on a dyno. I had a slight issue with my last revision were the rpms would hang during decel in first and second gear. I reloaded the prior tune and am now waiting to hear back about what could have caused that.

My car runs strong, but i'm sure with only street data logs i'm leaving a little on the table. When the time comes I will let lund remote tune my car on a dyno for the next pulley.

 

[stewarts2008]

well, i already have a good dyno tune that doesnt stall and runs great, but like i said, i am just interested as to why my car has been so much different to tune than other paxton set ups and im trying to figure out why that is.

 

[bam2012@TBR]

When you got the dyno tune did they start over or just work from the lund tune? Might give you an idea what the issue was, or is with your tune. Every car is different, but they should have got you in the ballpark with some logs.

 

[stewarts2008]

The dyno tuner started from scratch. He used the Boss strategy tune, 12 degrees timing, changed the cams around, took a little fuel out down low to keep it from being rich, and he thinks that it runs perfect. He also street tuned it by taking it out and making it butter smooth.

Just not sure why lund's tune has been giving me issues.

 

[BigMackCoyote]

Do you ever have the stalling issue when going to reverse or 1st from neutral?

 

[bam2012@TBR]

Do you ever have the stalling issue when going to reverse or 1st from neutral?

If you are asking me, then no never had any stalling issues.

 

[stewarts2008]

Do you ever have the stalling issue when going to reverse or 1st from neutral?

Nope, its only when moving forward and i clutch in, and put it in neutral to coast.... the RPMs drop, and either its fine, or it drops to around 500 RPM and stalls out.

 

[Blazer707@TBR]

OP, did your paxton kit come with a lund remote tune? Or just a "canned" lund paxton tune?

-Thomas

 

[stang8psi]

Do you ever have the stalling issue when going to reverse or 1st from neutral?

Nope, its only when moving forward and i clutch in, and put it in neutral to coast.... the RPMs drop, and either its fine, or it drops to around 500 RPM and stalls out.

Mine did this in both situations! And I had Jon tune my car first Hand on the dyno!

car was fine for about an hour after the dyno session, and than I have been back and forth with Jon for weeks, and logs, and tunes.. And it still did the same thing! Now I just don't get any responses or revisions, or anything? Kind of annoying and honestly pissed me off!

 

[stewarts2008]

Mine did this in both situations! And I had Jon tune my car first Hand on the dyno!

car was fine for about an hour after the dyno session, and than I have been back and forth with Jon for weeks, and logs, and tunes.. And it still did the same thing! Now I just don't get any responses or revisions, or anything? Kind of annoying and honestly pissed me off!

Yea, when i got ken to send me back to back revisions and i literally did logs back and forth for one afternoon... the tune got dialed in and had no problems.... later that night, it started stalling. Ken says that im the first this has happened to in all of his experience, but i know of 2 other people that are having this issue now. It sucks.

All in all, like i said, i have a great tune from somebody else, but this was kind of a let down. Every car is different, but there is something going on between all of our cars that is making this different. I think it has something to do with vacuum pressure and the BOV opening/closing at weird times, but i dont know if im going to invest anything else to investigate it.

 

[stewarts2008]

hmmmm, im looking at some of your signatures as well and the 3 people that i know that are having this issue have the boss intake manifold...... do you have one bam?

 

[bam2012@TBR]

hmmmm, im looking at some of your signatures as well and the 3 people that i know that are having this issue have the boss intake manifold...... do you have one bam?

No I do not have a boss intake.

 

[manolith]

i have the same issue that op is having. i have to get some data logs and send them to ken. its an annoying issue and kind of embarrassing sometimes because once the car stops you get slapped with gas fumes.

 

[stang8psi]

i have the same issue that op is having. i have to get some data logs and send them to ken. its an annoying issue and kind of embarrassing sometimes because once the car stops you get slapped with gas fumes.

Yes this happens also..