Problem with highway driving

[cwallace12]

Hopefully someone has had a similar problem as mine. While driving on the interstate running maybe about 75 to 85 under constant boost suddenly my boost gauge drops to 0 and I lose all throttle response until I push it all the way to the floor at which point my boost kicks back up and I resume to accelerate. I have replaced the TPS b/c the old one did have a bad spot in it when I ohm'd it out. This did not fix the issue. I then did some research and found that my boost controller was set incorrectly. This did fix the problem at lower speeds say around 70 - 75 and as long as I dont get into the throttle very hard. Above that though it still will happen. I have a s13 blacktop with t25, stock injectors, z32 maf, un-tuned ecu, and am running about 15lbs of boost. My boost controller is a greddy profec b spec 2. I have checked the ecu for codes and nothing comes up there either. Thanks for any help.

[the converted]

Not really much I can think of. Have you checked the turbo for shaft play? 15 psi is a little high for a stock turbo.

[cwallace12]

No I have not checked that yet. I am wondering though if maybe the boost controller could be the problem since it used to do the same thing at lower speeds before I adjusted it. I have it set to 40% gain and the set boost (2nd setting) which should control spool is set to 24.

[cwallace12]

To make a correction the maf is a sr20det maf not a z32. Could this problem potentially be a problem with the maf ,maybe the fuel pump, or a bad boost controller.

[IWANTAKOUKI]

Could be something like heat soak.

[cwallace12]

Could be something like heat soak.

I dunno. This problem was happening at lower speeds and less aggressive highway driving b4 I adjusted the boost controller. So I wonder if the solenoid under the hood might be bad. Street driving is completely unaffected by the way, this is only happening on the highway.

[the converted]

Take the boost controller out and see what happens.

[SullivanRacing06]

i thin kyour running outta fuel pressure, remove the boost controller like stated above n return the engine back to stock boost settings n see if its still cutin out, if this fixxes the problem then buy a walbro 255 pump, if not then its other issues

[the converted]

Yeah I'm sure he's running out of fuel cruising on the highway.......

[cwallace12]

i thin kyour running outta fuel pressure, remove the boost controller like stated above n return the engine back to stock boost settings n see if its still cutin out, if this fixxes the problem then buy a walbro 255 pump, if not then its other issues

Its already got a walbro.

[SullivanRacing06]

Yeah I'm sure he's running out of fuel cruising on the highway.......

because everyone drives at 70-80 at 5 psi of boost?

come on man giving suggestions

[RedlineDriftCoalition]

just an idea...cant say this could be it but if your turbo is spooling to quickly and the waste gate isnt letting some of the gasses to bypass the turbine it could make the turbo bog down over time....and in turn screw with the maf because there is to much of a pressure build up in the intake which could also cause the car to bog down....just a thought.