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I was driving the car about 2 weeks ago when out of the blue, the car lost it's boost. I could hear the blower whining away, but the motor felt stock. The boost was gone, but the belt was spinning. There was no knock under WOT (that I could hear), but I could hear the fuel pump buzzing away (my back seat was out for an autoX). Every once in a while I could hear a spraying sound from the area of my fuel tank. I looked under the car, but couldn't see any leaks.
I figured that my FMU was toast. I took it apart and found that the diaphram was warped. I phoned jr and they sent me a pair of new diaphrams (thanks jr http://www.hostboard.com/ubb/wink.gif ). I installed the repaired FMU, set the fp and took the car for a test drive. Even after letting the car warm up, it still drove the same way.
I noticed when I was fiddling with the FMU that when I gave it throttle, the guage didn't move. Is the jr FMU supposed to raise fuel when your not driving?
The mods I have on the car right now are a Holley fuel pump, a B&M FPR, cam gears, CAI, #7 cold plugs and a stock exhaust with a cheap muffler. The car has been dyno tuned to 200 whp.
Anyway, I'm working out a deal with a local shop for a stage 2b hondata, to get rid of this pos fmu. So I don't want to buy another FMU, but I still want to drive the car.
Any ideas, I'm stumped?
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I know it's a longshot. . .but have you checked the screws on your cam gears? I had an instance once where (I think) my exhaust cam screws came loose and became fully advanced/retarded. I can't remember which one. . . but the car ran terribly.
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6 psi JRSC GSR: GSS-317, 3" intake -> 217 hp/155 ft-lbs.
New: BTC, MAP controller, and stock timing!
Soon: Endyn stepper?
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If you've lost boost then you definitely won't see a rise in FP seeing as it takes it's boost reference from the intake. Check around for a blown out gasket and make sure the air bypass valve on the JRSC isn't stuck open for some reason. Are you registering any boost on your gauge??
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1994 GSR
JRSC
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DC2 gsr,
The boost guage is now on my WRX http://www.hostboard.com/ubb/frown.gif
I'll be sure to buy another one though. Then I'll know for sure if there is boost. An open bypass valve would make sense, as the air pressure wouldn't build enough to make the fuel rise. I'll check that, and double check my gaskets.
217gsr,
I took a look at the cam gears, and they're still tight and set. I didn't think this was a problem, as the car runs great..... just weak.
Thanks for the info.
Anyone else have any experience with this tyoe of problem?
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Sounds to me like the bypass valve is stuck open like DC2 GSR mentioned.. If I'm not mistaken this could be caused by the vacuum line that closes the bypass valve coming loose... this would also explain the spraying sound maybe. Just a thought...
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'99 Si 9lb JRSChgd
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when mine wasn't creating boost and the belt was spinning its because some gears in the nose of the blower decided to explode.. if a guage is saying 0 boost and that bypass is functioning, its certainly something to look at but time consuming..
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Ah.. You're right, oops... I had you thinking though!
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'99 Si 9lb JRSChgd
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Daurie:
Sounds to me like the bypass valve is stuck open like DC2 GSR mentioned.. If I'm not mistaken this could be caused by the vacuum line that closes the bypass valve coming loose... this would also explain the spraying sound maybe. Just a thought...
<HR></BLOCKQUOTE>
You had me thinking for a sec...
Only problem with that is that if the vacuum line is loose the valve will be stuck closed. The valve uses vacuum under minimal load to keep the valve open to divert compressed air from the charger back through the manifold... when you give it, the valve will close because insufficient vacuum is present to oppose the force of the spring.
Double check for a blown out gasket or stuck open bypass.
Mine is still idling high...... gonna gut it this weekend and seal everything well!
Ian
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1994 GSR
JRSC
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A quick update.....
I have secured a deal for Hondata 2b coming on tuesday. At that time, I'll also be looking into doing the Hondata intake gasket. At that time, I'll be able to check out the gears, while disposing of my FMU at the same time.
I'll be sure to bring the digital camera to take pics of any destroyed gears or fins. For some reason, I don't mind blowing the block, but if the s/c blew, I would be devastated.
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i dont want to scare you or anything, but when i sent my blower to jackson i got it back about a month later :P at least a piston or rings can be fixed locally and you can nag the people about it.. jackson just says "its at magnusen, we dont know when it will be done"
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