Flutter under boost

[91blazins10]

Re: Flutter under boost

You have a code 22-

Throttle position sensor/voltage low-Check TPS adjustment. Check the ECM connector. Replace the TPS.


That might be your problem. :dunno:

 

[Tooky]

Re: Flutter under boost

I looked at your file. Your boost comes up really fast. You're getting 15-16 PSI at less than 50% throttle. On my PT51 that was enough to get me into "compressor surge" which is a situation similar to when you slam off the throttle and our trucks make that "Pfffffttt" noise. The air being pumped into the motor is more than the motor can take and some of it is reversing back out the compressor wheel causing a really weird noise.

However - your shifts look nice and crisp so I'm suspecting a stock torque converter? In that case I'm not sure what to tell you. Does it run any different at WOT? Mine will only do the compressor surge if I do like your Datamaster file indicates - goose the gas about 50% and let it sit so the turbo spools without really being at WOT. Once I floor it, it clears up 100%. It's sort of an indication of a turbo being too large for the motor. However, I'm only offering a suggestion - your problem could be something totally different.

 

[viperman5]

Re: Flutter under boost

Is the code occuring on these runs or does DM store the last code thrown? When I replaced the clamps on the IC to TB, I unhooked the TPS started the truck up then saw the code and instantly knew what I forgot.

You have a code 22-

Throttle position sensor/voltage low-Check TPS adjustment. Check the ECM connector. Replace the TPS.


That might be your problem. :dunno:

 

[viperman5]

Re: Flutter under boost

Yes, I do have the stock converter. It is a 20g with 50 trim compressor wheel. It is interesting part throttle would give me that much boost. I will change the boost valve and get it dialed in around 20psi. I have not done this yet because of the current problem. I will then do a WOT pass and record the run.

I appreciate all the help.

I looked at your file. Your boost comes up really fast. You're getting 15-16 PSI at less than 50% throttle. On my PT51 that was enough to get me into "compressor surge" which is a situation similar to when you slam off the throttle and our trucks make that "Pfffffttt" noise. The air being pumped into the motor is more than the motor can take and some of it is reversing back out the compressor wheel causing a really weird noise.

However - your shifts look nice and crisp so I'm suspecting a stock torque converter? In that case I'm not sure what to tell you. Does it run any different at WOT? Mine will only do the compressor surge if I do like your Datamaster file indicates - goose the gas about 50% and let it sit so the turbo spools without really being at WOT. Once I floor it, it clears up 100%. It's sort of an indication of a turbo being too large for the motor. However, I'm only offering a suggestion - your problem could be something totally different.

 

[viperman5]

Re: Flutter under boost

I did the bike tube test today. I hooked it up to a compressor, pumped until the tube was nice and full then listened.

I can hear a hissing coming from passenger side. It sounds like it is coming from around or under the EGR.

Does that make sense to anyone? Normal or bad?

I'm with Jimmy
Definitely sounds like a boost leak. It won't run rich since it's a MAP-based system so the only negatives you'll find are possibly noise and a hotter intake charge (low power).

Do a bike tube pressure test.

 

[Jimmy]

Re: Flutter under boost

I did the bike tube test today. I hooked it up to a compressor, pumped until the tube was nice and full then listened.

I can hear a hissing coming from passenger side. It sounds like it is coming from around or under the EGR.

Does that make sense to anyone? Normal or bad?

You need to find the leak and fix it.

 

[viperman5]

Re: Flutter under boost

Are there gaskets in the area I describe? Could the EGR be making that sound with the bicycle tube filled with air?

You need to find the leak and fix it.

 

[Flyin Ryan]

Re: Flutter under boost

Are there gaskets in the area I describe? Could the EGR be making that sound with the bicycle tube filled with air?

There is a gasket where the egr valve bolts to the intake manifold if that's what your asking but can't help with the function of the egr as mine has been deleted.. but Im pretty sure it shouldn't many any hissing sounds when it's working though

 

[Ty1642]

Re: Flutter under boost

I'm digging up this old post because I was having the exact same problems as the original poster (when the engine hit about 10 pounds of boost, it would lose power and there was a 'fluttering' sound.) Below 10 psi it ran great, but as soon as it hit that level it would fall on it's face.

After trying several other fixes, I put in new spark plug wires as Dig had suggested several posts above. I hadn't tried that at first because they looked fine and were all zip-tied clear of the manifolds and downpipe. They also only had about 15,000 miles on them.

Changing them did the trick though - the beast is back. 18 pounds of boost on 94 octane without a hiccup. I've heard so many times how these trucks eat ignition components, but now I'm really a believer. Hope this helps someone else.

 

[viperman5]

Re: Flutter under boost

I changed the plugs and still have the problem. The truck is now at Rockford Racecraft as I am not having any luck.

I will be sure to post when we find the problem.

 

[Mtn Z]

Re: Flutter under boost

I had this fluttering problem for awhile. I changed the plugs, cap and rotor and none of them helped the issue. I decided to do the vacuum lines and plug wires. The problem went away. My vacuum lines were thrashed for the most part and I had a wire that had the sheath burned through. Who knows which one it was, but I would try checking all of the vacuum lines and the plug wires. The problem is probably simple and dumb like always.

 

[Syclone#2960]

Re: Flutter under boost

I am getting a flutter when I hit 10psi. Truck runs great, no codes, spools fine, can make boost as long as under 10 psi, it feels fine. Hit 10 psi, power goes away and I start hearing a flutter sound coming from the turbo area. You can feel it in the truck slightly.

Here is what I have done:
Took air filter off to make sure it was not coming from intake and re-secured.

Took turbo to IC hose off and re-secured.

Thought my IC to Throttle body was loose. took off and used T-bolts to secure.

Thought my boost control solenoid was bad so I went back to boost valve.

Thought waste-gate actuator was bad, took off put old working one back on.

Prior to this happening, had waste-gate ported, 3"DP put on. Truck ran fine when I got it back for about three weeks.

Any help would be appreciated.

Jay

Well Jay As I stated before I was having similar symptoms as you. I was going to replace the pte67 w/ the new 52 turbo and noticed my waste-gate arm was sticking. I loosen up all the Allen head bolts that hold the turbo to the down pipe and walla the arm stops sticking allowing the waste-gate to close complete. I should know if this fixed the problem tomorrow.

 

[viperman5]

Re: Flutter under boost

Turns out the cause of my flutter was too much ALKY. Turned the ALKY down, flutter goes away, turn it back up, flutter comes back. It was set at around 7 on ALKY control controller, set just under 3 and truck runs great.

 

[chicows18]

Re: Flutter under boost

Turns out the cause of my flutter was too much ALKY. Turned the ALKY down, flutter goes away, turn it back up, flutter comes back. It was set at around 7 on ALKY control controller, set just under 3 and truck runs great.

What is ALKY?

 

[TNPhoon]

Re: Flutter under boost

What is ALKY?

alcohol injection