Hesitation and high KR Cold weather issues?

S

ShoBoat

New member
So i have put my girl back in her summer mode once again, a little early this year. Installed my H&R's, summer wheels, tune, intake and 3 bar. Mine has the V8 LMS tune. I started seeing some KR at lower RPM's at 60 to 70 mph at mid throttle. Then I started to replicate the issue while logging with Forscan and my laptop. AT mid throttle (without downshifting) (once boost got above 4 PSI) I was seeing KR of 4.5???? I decided to try some WOT runs, no KR to speak of but I am getting a hesitation (shudder) at the top end to 2nd and 3rd. I checked all the usual suspects, oil in the CAC nope. Plugs, changed them and gapped to 30. Air cleaner check. Fuel was the last on my list as we still have winter gas in the pumps, changed stations and filled up with 94. No change. Called LMS and they said its probably the fuel. SO in goes some 110 Octane fuel. That should fix it? Nope.... So I then tried to load the 91 V8 tune. Same issues. Frustrated I went to the stock tune and the issues go away. I changed the map sensor only and returned it to stock. All other mods stayed on the car. I even swapped out the map sensor to rule that out. No luck. It was running strong at the end of last year with no problems with the tune and all the mods. I did put the winter package on a little early so it was still above freezing when I did.

Any thoughts? Has anyone experienced similar issues? 
 
I have noticed at any speed if I accelerate w/o enough throttle to get a downshift KR will rise.  As far as the stutter... Makes me think about the transmission speed sensor... I think  there is a TSB on that.
 
Thanks BiGMaC, I will look into that. Interesting that it only happens with the Tune loaded. That will be difficult to explain to the dealer lol.


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I see the same thing in terms of knock with winter gas but I don't have any hesitation so I'm not sure your symptoms are related?
 
ShoBoat said:
Thanks BiGMaC, I will look into that. Interesting that it only happens with the Tune loaded. That will be difficult to explain to the dealer lol
Click to expand...

Larrylu had a heck of a time getting them to replace his, but it resolved the shift problem... Otherwise gotta look to the tuner about excessive shift pressures ... Often over 200psi will cause problems.
 
Have you tried to something to eat up the possible water build up in gas tank?

Almost sounds like infant stages of injector issue also.

Rich

 
It could be the case that the 2 are unrelated. I will speak to my Dealer regarding the TSB. I will also be speaking to LMS on Monday. The KR was non existent last year in warmer weather. Thanks for the responses.


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SHOnUup said:
Have you tried to something to eat up the possible water build up in gas tank?

Almost sounds like infant stages of injector issue also.

Rich
Click to expand...

Injector issues, damn I'll look into that one too.


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BiGMaC said:
I have noticed at any speed if I accelerate w/o enough throttle to get a downshift KR will rise.  As far as the stutter... Makes me think about the transmission speed sensor... I think  there is a TSB on that.
Click to expand...
Some e-85 will stop that completely and give you -KR instead  :)
 
Shoboat, you could drop a couple bottles of heet in on next fill up his in case its H2O in the tank.

Heet just happens to be 99% meth as well....
 
Did you check for any loose turbo,cac,wastegate hoses being loose or split due to the cold weather,also clean those map,iat sensors with some maf cleaner.Z
 
Thanks for all the responses, I did double check the hoses. I am going to be tearing all of the hoses off and clean the tb and sensors tonight. The heet idea also sounds interesting. I am also going to take some pics of the intake valves with my snake cam. Will report back.


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ShoBoat said:
Thanks for all the responses, I did double check the hoses. I am going to be tearing all of the hoses off and clean the tb and sensors tonight. The heet idea also sounds interesting. I am also going to take some pics of the intake valves with my snake cam. Will report back.


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Click to expand...
I wondered about the valves as I read over your posts...great idea.

When you logged did you notice any changes in fuel data compared to old logs?

Rich

 
When issues "go away" with the stock tune, it is usually because the engine/drivetrain is not being asked to perform to as tight a tolerance as with a tune.  So what might be acceptable stock/OEM, becomes unacceptable tuned.
 
So after a bit of time messing around in the garage, I am no closer to discovering the culprit. I have looked into the intake and CAC with my snake cam. Found noting really special in the intake, no real additional build up on the valves. And the CAC is bone dry. Cleaned the TB and sensors. I have gone over the logs and compared them to last year the only thing that stands out is the outside temp. Today it's a balmy -1C and like my friends to the South we also had some snow overnight. Since I also tossed in 10L of 110 race gas, I'm thinking it's not fuel related.
The shudder is registering as misfires (feels like it too) on Forscan and Torque. With the stock tune it's perfectly fine, no shudder and nearly 0 KR at all. At least the list is getting smaller.

Spark blowout? (Doesn't explain the KR) Also plugs are at 30.
I know that with the V7 LMS tune some were reporting similar issues. Maybe Tune? In combination with the cold? (Could possibly explain both)
Injector(s)?

I still plan on getting with the guys at LMS tomorrow and see what they have to say. I should be able to get my dealer to do the TSB for the trans. 

SHOnUup I had my trans fluid changed last fall. But thanks anyway. 
 
Oh one other thing, what all the talk of blowing turbos with induction cleaning. Is anyone still doing this? I wanted to have this done (again) this spring but am on the fence.
 
No codes being set?  I know you said Forscan/Torque are registering misfires.  I would pay attention to a faulty injector possibility, maybe more than 1.  How are the fuel pressure readings?
 
ShoBoat said:
Oh one other thing, what all the talk of blowing turbos with induction cleaning. Is anyone still doing this? I wanted to have this done (again) this spring but am on the fence.
Click to expand...
I don't think the BG service is really worth it. I had the service completed 6-6-14 @ 33,291 miles.
I just rechecked my intake valves and CAC today.
I'm now at 39,400....... So a little more than 6,000 miles and they still look like this......
d2c5788b9c1be678a7c9a670f6d3b1e6.jpg

f2c7a7a6365d89f12460f71205f46254.jpg

http://tapatalk.imageshack.com
v2/15/04/05/1252de3b73888e52948843e056c56b35.jpg

2010 RCM non PP
K&N panel filter
sp534 @ 30
unleashed 93 performance+boost 3bar
more to come.....

 
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