Boosting for no reason??

[changeddsm]

I have a 90 laser w/JDM cyclone motor,HKS boost controller and a few other little mods done. When I'm driving down the highway the car will just boost for no reason.(gradually about 5-10sec.) I don't mean a little either it pegs my stock boost guage. If I let off the gas it will drop but it does it again shortly. I can rev the car and it goes away for some time but then it always comes back. Any ideas????

 

[DSM90AWD]

The stock boost gauge is controlled by the ECU to approximate boost by using input from the MAS, TPS and engine RPM (i.e. not accurate).

The erratic behaviour may be an indicator that one/more sensors is going bad (do you have a CEL?) or that the ECU is either bad or has an aftermarket EPROM inside that is using the stock boost gauge to read other data (Knock, timing.etc) ala TMO / DSMChips.

 

[xchox]

Check the computer harness under the carpet/dash passenger side! I took my car in for a stereo install at The Power Center and the slit the wires! Now the turbo wasnt kicking in as your describing but the car was doing weird things! Hamilton Audio fixed everything my talon needed and she works fine now! So if you have problems down there it may cause problems with the sensors!

 

[oldman]

Check your ECU. When mine was on it's way out, it would do something wired like that. One time I was coming to a red light in neutral and the rpm shot up to 6k, I had to pull over and shut the engine off.

 

[DSM90AWD]

One time I was coming to a red light in neutral and the rpm shot up to 6k, I had to pull over and shut the engine off.

nice.. did the officer buy that one

 

[oldman]

nice.. did the officer buy that one

Funny you said that, I actually pulled into a police department parking lot, were you there?

 

[DSM90AWD]

unless the statute of limitations has expired for unpaid tix.. I'm still not allowed to drive in NJ

Actually reminicent of an "incident" I had at a stop light as a teen with my '80 Toyota Tercel in which I "spun wheels" (what the ticket said) for nearly 40feet.

I used a similar excuse.. but didn't work so good

 

[oldman]

unless the statute of limitations has expired for unpaid tix.. I'm still not allowed to drive in NJ

Actually reminicent of an "incident" I had at a stop light as a teen with my '80 Toyota Tercel in which I "spun wheels" (what the ticket said) for nearly 40feet.

I used a similar excuse.. but didn't work so good

My license has been suspended since 1992 and that's a year before I got my dsm. I live right across the street from the PD.

 

[changeddsm]

I just got a new ECU so I now it's not that before my old ECU went out it did it too. The shop that did my swap opened the BOV to the atmosphere could that be part of the prob???

 

[oldman]

I just got a new ECU so I now it's not that before my old ECU went out it did it too. The shop that did my swap opened the BOV to the atmosphere could that be part of the prob???

First I would recirculate anyway, see if that helps the situation. Did you get jdm ECU as well with the swap? Maybe you didn't get the correct jdm ECU replacement.