www.gt4dc.co.uk
Maintain, Modify and DRIVE your GT-Four


It is currently Thu Mar 28, 2024 11:35 am




Post new topic Reply to topic  [ 4 posts ] 
Author Message
PostPosted: Mon Oct 13, 2014 9:56 pm 
Offline
Group N

Joined: Mon Oct 24, 2005 3:21 pm
Posts: 347
Car Model: None
All this doom mongering about the worst winter since ever in a The Day After Tomorrow movie style has stuck a boot up my backside and it's time to get my Four running again.

After a timing belt change debacle that lead to a head off episode, it all went back together and drives fine. (Well, it did when I last drove it 2 years ago, ahem)

Haven't given it any boost though as the boost gauge on the dash is reading inverse / inverted. Cruising is shows positive boost but then give it some welly and it does down towards vacuum.

AVC-R and mechanical boost gauge plumbed in to the same hose tell me I don't have a physics bending engine and actually it is boosting as it should so just the dash gauge reading is wonky. Thing is, I have it in my head that's where the ecu gets it's boost reading from so don't need it leaning out under boost thinking I'm cruising.

My best thinking is a knackered MAP sensor, anything else easy to try and swap out?

_________________
02 Mini Cooper Race Car
94 ST205 Import
92 ST185 Carlos Sainz
www.mcnab-racing.co.uk


Top
 Profile  
 
PostPosted: Mon Oct 13, 2014 11:35 pm 
Offline
Club Staff
User avatar

Joined: Wed Jul 13, 2005 12:06 am
Posts: 4743
Location: Perth, Western Australia
Car Model: ST205
If the MAP sensor was truly knackered then from my experience the car goes into limp 'get you home' mode. Doesn't sound like it's that bad from your description. Is it possible it's just the dash gauge which is knackered? I'd need to refer to the BGB to trace where it gets its signal from. Like you say, you don't want to take any risks by boosting and risking lean running until you get to the bottom of the problem just in case the ECU is taking this erroneous boost reading and matching the fuel to it.

It's handy having a spare 205 in the driveway for swapping components!

Not much help I know :oops: :?

_________________
Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp


Top
 Profile  
 
PostPosted: Tue Oct 14, 2014 7:37 pm 
Offline
Group B
User avatar

Joined: Sat Sep 02, 2006 3:13 pm
Posts: 3679
Location: Bournemouth
Car Model: None
If it's a 185, then the boost sensor is only used for boost cut and possibly ignition retard (I know an RC someone had disconnected it as a crude FCD and it pinked at full boost).

If the MAP sensor were faulty on a 205 to the point of showing boost while on light throttle, then it would run very badly if at all. Far more likely gauge IMO (My 205 the gauge reads very high intermittantly with no change to engine performance. I've also seen similar on someone elses).

_________________
If at first you don't suck seed, try drier grain.

Image


Top
 Profile  
 
PostPosted: Wed Oct 15, 2014 12:17 pm 
Offline
Group N

Joined: Mon Oct 24, 2005 3:21 pm
Posts: 347
Car Model: None
Should have said, it's an ST205. The engine is still running sweet at idle etc and pulls well at the moderate throttle ticklings I've given it.

_________________
02 Mini Cooper Race Car
94 ST205 Import
92 ST185 Carlos Sainz
www.mcnab-racing.co.uk


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 


Who is online

Users browsing this forum: No registered users and 17 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group