- Vauxhall Tigra 1999 X14XE Hard Starting Archived Message
Posted by Dave Hill
on September 29, 2008, 9:54 pm
|
I have this Tigra that is a pig to start & keep running. It will initially fire up, but boggs down & struggles to rev giving the impression that it is flooding. It will fire up with a Wide Open Throttle presumably this activates the “Anti Flood” strategy. After a few seconds it will rev cleanly & although a bit gutless, it doesn't present a problem again until next start up. There were no DTC’s initially, although at times throughout the job there has been a "P0505 Idle Control System" code logged. I think that this code was logged because the target idle wasn’t achieved. The one thing in live data that stands out as a likely issue, is the MAP value. Shortly after startup the MAP shows 0.48 bar & this is confirmed with a vacuum gauge. Also when it wont start, the MAP value shows 0.98 bar. Compressions tested from cold are all around 150 psi which isn’t great but hardly terminal (open to opinions of course). I am seeing around 15 in/HG at idle when warm & performance on the road is poor too. Other checks performed are…… Crank pulley checked for the usual free play & correct valve timing confirmed. EGR commanded & position feedback confirmed. Fuel pressure & flow confirmed. Archives searched!  Ignition confirmed with scope (although the trace does show it flooding when fault is present) Exhaust pressure checked for blockage. Idle Speed Control Valve steps are seen to respond to engine load at idle. Intake & Exhaust has been smoke tested. Brake servo hose clamped. O2 sensor seen to switch nicely (single wire type) although the fault is at immediate startup, so I don’t think the O2 sensor is a factor. I am chasing the theory that the MAP is too low & causing an over rich condition. I have had the situation previously where a wide-open idle control valve has caused a loss of vacuum like this. I had planned to remove & blank off the EGR to prove a point, but felt happy that the feedback test proved that it was closing ok. I will post some data snapshots separately. Any suggestions gratefully received. Cheers all |