boostin'euro89 Posted May 31, 2007 Report Share Posted May 31, 2007 Im having trouble with my 89, its overboostin to almost 20 psi after removing the manual boost controller, everything on the car is stock except for the KandN Filter and the BOV, i checked the wastegate and seems ok all help would be appreciated Quote Link to comment Share on other sites More sharing options...
Johnny Posted May 31, 2007 Report Share Posted May 31, 2007 Are you sure that the wastegate is ok? (checked it with pressure) If it is, then you must have a major leak somewhere or the electrovalve is malfunctioning. Quote Link to comment Share on other sites More sharing options...
boostin'euro89 Posted June 1, 2007 Author Report Share Posted June 1, 2007 how would u go about checking it with pressure, because the car wont hit that much boost at stand still, i have messed around with the electrovalve while removing the MBC (Manual boost controller), but shouldn't the overboost sensor kick in regardless?? at the time of the MBC removal i did replace the cracked vaccum lines to the actuator also to the inlet pipe. when i first got the car, it had a boost guage installed, and read only 7 psi max boost, untill when installing the MBC i noticed a major leak in one of the vaccum lines, replaced it and installed the MBC (I should've listened before the MBC is not a good idea in the N9T**) the car runs smooth and all now it's just the overboost that killls the fun Quote Link to comment Share on other sites More sharing options...
Johnny Posted June 1, 2007 Report Share Posted June 1, 2007 With a bicycle pump or a compressor hooked up to the wastegate-hose. The wastegate should start moving at about 5 psi. The overboost sensor should kick in at around 16 psi I think, and limit the rpm. If you want to rule the electrovalve out you can simply take the hose that goes to the wastegate and connect it to the one that goes to the compressor-side on the turbo. Put something in the third hose that goes to the accordian-hose so the engine doesn't suck in air there, maybe a bolt. It sounds very probable that the diaphragm is broken inside the wastegate. Quote Link to comment Share on other sites More sharing options...
boostin'euro89 Posted June 1, 2007 Author Report Share Posted June 1, 2007 Is the N9TE and the N9TEA wastegate the same?? Quote Link to comment Share on other sites More sharing options...
geo Posted June 3, 2007 Report Share Posted June 3, 2007 With a bicycle pump or a compressor hooked up to the wastegate-hose. The wastegate should start moving at about 5 psi. The overboost sensor should kick in at around 16 psi I think, and limit the rpm. If you want to rule the electrovalve out you can simply take the hose that goes to the wastegate and connect it to the one that goes to the compressor-side on the turbo. Put something in the third hose that goes to the accordian-hose so the engine doesn't suck in air there, maybe a bolt. It sounds very probable that the diaphragm is broken inside the wastegate. According to the factory manual that I have, at 16 psi boost the overboost sensor cuts the fuel injection, it doesn't limit the rpm directly. You should never be getting 16 psi boost, so I agree that there is probably a problem with the wastegate, as mentioned above. George Quote Link to comment Share on other sites More sharing options...
boostin'euro89 Posted June 3, 2007 Author Report Share Posted June 3, 2007 Do the N9TE and the N9TEA use the same wastegate? Quote Link to comment Share on other sites More sharing options...
Johnny Posted June 3, 2007 Report Share Posted June 3, 2007 According to the factory manual that I have, at 16 psi boost the overboost sensor cuts the fuel injection, it doesn't limit the rpm directly. You should never be getting 16 psi boost, so I agree that there is probably a problem with the wastegate, as mentioned above. George Well, if you cut the fuel injection, you are limiting the rpm directly. The rpm-limit works the same way. I don't know for certain if the N9TE and the N9TEA use the same wastegate, but it's not unlikely. Quote Link to comment Share on other sites More sharing options...
august Posted June 6, 2007 Report Share Posted June 6, 2007 yes, the N9TE and N9TEA use the same wastegate actuator. as johnny said, connect a bike pump with a t'd in boot gauge and see what pressure the wastegate opens. (also, see the pressure testing pic in the project 505 blog: http://www.505turbo.com/86505/blog/archive...e-actuator.html) let us know what happens... Quote Link to comment Share on other sites More sharing options...
boostin'euro89 Posted June 7, 2007 Author Report Share Posted June 7, 2007 yeh it was the wastegate and what a fun job it was to replace but......i think i enjoyed the overboost now it'll hit about 8 psi in first. 10 in second, and 11.5 in third and thats max, but it fluctuates i think the TPS is off, gonna have to recalibrate it because i have to push the throttle a little too much to get anything at all after a shift or even on start up sorry not "start up" but i meant just to get going in first Quote Link to comment Share on other sites More sharing options...
billbranch Posted January 9, 2008 Report Share Posted January 9, 2008 Hi, Everyone, While we're on the subject, my newer '91 N9TEA is boosting uncontrollably, and I am 99.99% sure pending the pressure test tonight that the actuator has fait caca. Where is the best (=cheapest) place to get a new one? Can the unit be replaced from under the car after jacking up the engine and removing a motor mount? If, by some fluke, it's the electro-valve, are there any tests? Will I suffer any poorer performance if I just by-pass it and go straight to the actuator? Thanks for any info. Bill Quote Link to comment Share on other sites More sharing options...
august Posted January 9, 2008 Report Share Posted January 9, 2008 Hi, Everyone, While we're on the subject, my newer '91 N9TEA is boosting uncontrollably, and I am 99.99% sure pending the pressure test tonight that the actuator has fait caca. Where is the best (=cheapest) place to get a new one? Can the unit be replaced from under the car after jacking up the engine and removing a motor mount? If, by some fluke, it's the electro-valve, are there any tests? Will I suffer any poorer performance if I just by-pass it and go straight to the actuator? Thanks for any info. Bill it might actually be a good test to bypass the electrovalve. the only check i know of for the EV is just a simple resistance check with the key off, other then that i'm not sure. you will notice a good amount less boost if you bypass the electrovalve, but it will still *work*. you can always re-adjust the length of the actuator rod to increase the boost level. let us know... Quote Link to comment Share on other sites More sharing options...
bill Posted January 10, 2008 Report Share Posted January 10, 2008 Bill, I would check the vacuum (pressure) hoses first. Also check the movement of the wastegate. I had them seize up a couple of times from rust. I was able to free them up with some PB Blaster and some persuasion with a small prybar. I got my actuator from erikssonindustries.com. It was about $100 exchange a few years ago. I know that the turbo will not come off from up top. It looks like it might, but it's about 1/4 inch or something too big to clear the mount. As far as replacing, it's pretty tight in there. If I had to do it again, I would undo the turbo as a unit, removing the exhaust manifold and then unbolting at the bottom. Yes, you do have to remove the motor mount to get the bottom free. Once it's out, it can be worked on in a vice. When I did it, I had to take the exhaust manifold into the machine shop to have it trued it up. -Bill Hi, Everyone, While we're on the subject, my newer '91 N9TEA is boosting uncontrollably, and I am 99.99% sure pending the pressure test tonight that the actuator has fait caca. Where is the best (=cheapest) place to get a new one? Can the unit be replaced from under the car after jacking up the engine and removing a motor mount? If, by some fluke, it's the electro-valve, are there any tests? Will I suffer any poorer performance if I just by-pass it and go straight to the actuator? Thanks for any info. Bill Quote Link to comment Share on other sites More sharing options...
billbranch Posted January 21, 2008 Report Share Posted January 21, 2008 Hi, again, an investigation has revealed that the the diaphragm is torn. "While the exhaust manifold is off," I am also going to the seeping oil leaks at the head gasket eliminated. Since I have an excellent transmission and the body is sound, I don't mind spending a few g's, and I'll also have a chance to get rid of a lot of silicone the trained ape used when he "fixed" the engine last time. Bill Quote Link to comment Share on other sites More sharing options...
billbranch Posted January 25, 2008 Report Share Posted January 25, 2008 Last night I got the call after the head was pulled. I have the "service" records from the old owner. This is unbelievable. The gang down there did a head gasket four or so years back, and it looks like they re-used the gasket and didn't bother to resurface the head. The head slid off the block when the last bolt was removed. Another of the service records indicates that the wastegate actuator had been inoperative about the same time and that the same outfit fixed that up, too, and for some reason set the boost at seven pounds. I'll know today (Roger's dropping the pan) the condition of the pistons. Isn't life grand. Quote Link to comment Share on other sites More sharing options...
billbranch Posted January 31, 2008 Report Share Posted January 31, 2008 Hi, again, and I hope I haven't hi-jacked this thread, but here goes. The pistons appear to be OK. I had bad leakdown in one cylinder, and the rings had been installed with the joints vertical. The bolts holding the oil pan were finger loose. The head was cracked. I had a spare in the basement which was also cracked. The shop repaired the head which would be more viable. So, I'm getting new rings. New timing chain and tensioner. New bearings if they're available (any hints)? I saw that thread. New wastegate actuator. The head's been welded. It could have been a lot worse. Quote Link to comment Share on other sites More sharing options...
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