DEKA

Problem
Lack of power/boost idle speed is around 1500rpm. This is only happening now and again.
Car will boost up to 1.1bar on the boost gauge when running ok. But when it hangs back its only hitting 0.5
Car spec
93 wrx import, Blitz sbc boost controller,HKS fuel cut defencer, HKS air fuel ratio regulator, K&N cone filter, irridium plugs, centre section de-cat.

I have recently replaced 4 coilpacks, O2 sensor and the plugs.

I have done a Diagnostic check and there are no fault codes flashing, If the MAF sensor was on its way out would i be getting this problem?
Would it not show as a fault?

Any suggestions welcome
DEKA

red wrex

I have had this problem lately, mine runs at about 1100 for a while (even when warm) then drops to 900 after about 25 mins

I found when i reset the ecu ( as you told me how to) It seems to have cleared it up, it started doing this when i put my pipercross filter and dv26 on

If all else fails call out the trusty cleaning fluid!!

DEKA

I have cleaned the boost solinoid/pipes, i have also cleaned the MAF sensor with a cotton ear bud. Still the same
Very puzzled and starting to get P1$$ed off

The_Judge

Does it do it in all gears?

My money would have been on the MAF, as you've ruled out most other things. What was on the end of the cotton wool bud? It still might be shagged, even though you've "cleaned" it. Have you tried disconnecting it with the (warm) engine idling, to see if the revs drop? Also, have you tried resetting the ECU to see if it makes it worse...?

You say you've tried cleaning the wastegaste solenoid. Does the Blitz still need that connected then? I've only got experience in Dawes/GBE type controllers...

I'm wondering if it's going into limp home mode, as 0.5bar is quite ominous...

You would only get a CEL error if the MAF was completely shagged, or disconnected...

DEKA

When i cleaned the maf it was fairly grubby, the cotton but was covered in dust/grease.
I will try disconnecting the maf when the engine is warm also will do an ecu reset
As for the controller i had it fitted around 18 months ago, and have never changed any settings that was programmed into it.

The_Judge

Sorry, what I meant was what cleaning product did you use on the cotton bud...!

Do you know if the hose to the wastegate solenoid is connected to your Blitz, or simply disconnected and plugged?

DEKA

Disconnected MAF when engine was warm, revs dropped and the engine stalled.
Reset the ecu(no faults) seems a little better
Thrashed it along the duel carrige way
When i get to about 5000/5500rpm engine seems to hesitate a little. Seems to only do it in 3rd,4th and fifth gear

The_Judge

You've got an AFR regulator, but what about an AFR gauge? Be interesting to know what it's doing under WOT. And what about a knocklink...?

Also, what fuel you running it on? Should have asked that first really...

DEKA

No afr gauge
Knocklink fitted lights bottom green light(bright) when hitting the red on the rev
counter
Use Optimax and Millers booster

DEKA

If the afr is not set correct
Would this cause this problem?

The_Judge

Is your knocklink set to max sensitivity (fully clockwise)?

Is the sensor installed in the right place (under near side of TMIC)?

Have you lit up all the lights on it to prove it's working OK (gentle tap of bolt holding sensor, or a firmer knock of the block near the sensor)?

Optimax and millers is probably as good as you're gonna get without getting a ScoobyECU mapped to our fuel (which is probably a good idea anyway!)

Regarding the AFR regulator, never used one so can't comment...

DEKA

Yes knocklink is set up as you have described, and have done the knock test and all lights light up.
Dont really want to adjust the afr dont feel confident enough
Thanks for the advice it has been very helpful
DEKA

The_Judge

Sorry couldn't be of more help... hopefully someone knowledgeable will be able to sort you out.

DEKA

MAF sensor failed on Saturday.Fitted new one today and the problem as described in my first thread is still there. My next question is. If the boost solenoid is failing will this cause the problem?
What is the best stuff to clean the boost solenoid

The_Judge

The wastegate solenoid would certainly be a possible reason for your boost problem, assuming it's still connected (as stated above, I'm not sure about the setup of the Blitz SBC).

It wouldn't be a reason for your idle problem though. You've changed the lambda and MAF sensor, which rules those out. Another possibility would be ICSV (idle control solenoid), which I think is cleanable in the same way as the wastegate solenoid (with brake cleaner). The only other thing I can think of is the TPS (throttle position sensor)...

DEKA

The wastegate solenoid is still connected. I have gave it a good clean plus all the pipe work, fingers crossed it seems okay at the moment.
What is the price roughly fo a new boost solenoid?

The_Judge

Don't know, but you could try somewhere like Grade A...