sti-spec-a

Please this has been doing my nut in BIG style

Started on a motorway trip sitting at 60-70 The CEL came on,i pulled on to the hard shoulder The revs would pulse very gently around the 1600 mark,switched it off,restarted it everything ok idled at 900 no CEL
When i got home connected the black plugs got 3 codes 24 44 and 45 ( Idle valve,MAP sensor and wastegate control solenoid ) Cleaned the 3 parts up Connected the green plugs to do the ECU reset,i could hear the relays fuel pump fans all giving it yeeehaaa but not the boost solenoid It wasnt clicking
Changed for one i knew was working but nothing I carried on with the ECU reset fine flashed up the all clear but still no clicking from boost solenoid

A couple of days later CEL light came up again on the motorway for about 10 seconds then off,i pulled into McDonalds checked the code 24 44 and 45 Started it CEL stayed on revs pulsed gently about the 1600 mark for about 30 seconds then dropped to 900 and idled perfectly but the CEL stayed on Drove home like a nun replaced the MAP sensor and idle control with ones i knew worked ECU reset fine

Again a couple of days later started it,after being sat in garage for a week,CEL stayed on and idle speed was 900rpm and the engine was stone cold Same 3 codes Switched it off then restarted it perfect cold idle speed,about 1250 Its really starting to scramble my brain I cleaned the 2 multiplugs behind the battery and the one under the intercooler Started her perfect idle CEL stayed on for about 2 or 3 seconds then off The boost solenoid was now clicking away Done an ECU reset everything was fine for about 2 months NOW its back every so often the CEL will come on either when driving (it will go back off after 10-30 seconds) or when i start it (either hot or cold)

Here are my questions

1 Would a bad earth between the battery and body give these symptoms?

2 Do these 3 components affect each other when they fail?

3 The multiplugs behind the battery and under the intercooler can they be bypassed?

4 When the CEL was off and the boost solenoid wasnt clicking away in neutral Boost was 1bar in 1st 2nd 3rd 4th and 5th tailing off gently to 0.7 at 5500rpm up to the redline With the CEL off and the boost solenoid clicking away in neutral Boost was 0.5 bar in 1st 0.7 in 2nd the 1bar through the rest of the gears again tailing off at the top end Does the ECU control boost in first and second by cycling the boost solenoid?

5 Is it a limited fuel supply in first and second according to a set fuel map or will it fuel according to the amount of air flowing past the MAF ie Is the engine being fuelled for 0.5bar in first and because the boost solenoid is releasing the pressure when its workin(clickin) or is the engine being fuelled for 1 bar because MAF has seen x amount of air and the MAP sensor is registering 1 bar when the boost solenoid is not working

Cheers Grant

sti-spec-a

Please help

Cheers Grant

XNWRX

It seems you have an electrical problem. Did you checked the harness between ECU/MAP/Solenoid ? I bet your problem is here.
Nothing to do with MAF anyway.

ANDYUK300

Grant,
would colin not be able to shed some light on this?

andy

STI5300

iTrader: (4)

Why don't you connect the self diagonistic check to see if it has recorded something when the car is cold , then try resetting the ECU. I had a throttle sensor fault come up only for it to dissappear when I reset the ECU !!!

The_Judge

When you perform the ECU reset, and you drive around waiting for the CEL to flash, how long does it take? And when it flashes, does it indicate all clear?

sti-spec-a

Judge some times when i reset the ecu it will display all 3 codes other times the all clear will flash up after about 20-30 metres Last night i pulled the i/c off spent ages cleaning all the connectors in the multiplugs ( im now convinced that this is where the problem lies) Went a run up the braes to give some stick not a problem Although im not counting my chickens

Andy , Colin and Bill are both stumped I need to find a good Auto spark locally to either check resistance between component and ecu

I now have 2 extra 3 port boost soleniod 1 idle control valve and a map sensor surplus to requirements

Cheers Grant