bales 1 Posted June 12, 2007 As the title suggests I have been having a few niggling annoyances with my car. I have driven a lot over the last 2 weeks and put a fair few hundred miles on it. The last few days it has just started to run a bit rougher and not subjectively pull quite aswell, I know that I am probably getting used to it and it has been hot recently but something just doesn't seem quite right. It seems to miss slightly when cruising at a constant throttle, it almost seems to "drag" like a calliper is binding but it isn't, and it is jerky when accelerating gradually and the transition period between on and off boost is jerky. It is also very very vocal in terms of pops and bangs, I know they all do it a bit but mine is silly I nearly made a cyclist fall off his bike again the other weekend as I had a huge bang when I backed off Plus I still have the same problem I have had from the start that it wont blip when in neutral when warm, it just misses and coughs and farts flames out of the exhaust when you try I think it is fuelling so being logical about it as the main inputs are MAP, RPM, Lambda and air temp I think that I have maybe an issue with the MAP sensor or the Lambda sensor. The tube leading into the ECU where tha MAP is, is actually a bit damaged so this causes me to think that. I also think that the solenoid could be causing the jerky on off transition between boost as this is what it is supposed to stop, but it still boosts up to 0.5bar fine - but I never see 0.7-0.8 bar which suppposedly it is mean to hit on overboost or in the higher gears So tonight I disconnected the solenoid to see if it ran any smoother - which it did slightly, but what worries me a bit is that the wastegate should then see no signal whatsoever and the turbo should produce maximum boost like 22psi or whatever some people have reported. But mine ran to a bar very neatly and then began to tail off, I only drove it for about 2 mins like this to see, but to be honest it was nothing like what some people have described when running uncontrolled boost, it seemed "slightly" faster and just made slightly more chuffing when backing off. It concerns me as surely when having no wastegate signal I should see significantly more than a bar for s short period when it is uncontrolled? Any idea's to why this could be? If anyone has any suggestions to the general poor running it would be appreciated, I intend to go methodically through all the suspect sensors and see what sort of results I get and then go from there. Cheers Alex Share this post Link to post Share on other sites
sonofsam 5 Posted June 12, 2007 What fuel you running it on? Mine used to pop and bang, doesnt do it so much now What condition is the lambda/ignition amp/? Try another poss. Check all pipes/hoses against a picture of stock setups. I think the overboost may have been in my head, but I still see 0.65 bar on regular occoasions. Has the wastegate actuator rod been tampered with? Have you tried reading the fault codes from the ECU, this may give you an indication. Had a few nigggles with mine mate, dont worry it'll get there Share this post Link to post Share on other sites
sonofsam 5 Posted June 13, 2007 Check your spark plug's/gaps aswell mate, also a bit dubious of your VSS as it well help control fuelling on over-run. Share this post Link to post Share on other sites
craig f90 0 Posted July 9, 2007 Check your spark plug's/gaps aswell mate, also a bit dubiousof your VSS as it well help control fuelling on over-run. Which vss are you using? ive got 2, but both have no hole for a speedo cable Share this post Link to post Share on other sites
Mikey S 29 1 Cars Posted July 10, 2007 Which vss are you using? ive got 2, but both have no hole for a speedo cable im pretty sure some of the later 405's have speedo cable holes in the vss sensor. Share this post Link to post Share on other sites
craig f90 0 Posted July 30, 2007 Cool ill take a look. thanks. Share this post Link to post Share on other sites
