Mazda Rotary Club

Cars by Model Type => 3rd generation RX-7's => Topic started by: ds2000 on June 27, 2007, 11:54:32 AM

Title: Boost issues
Post by: ds2000 on June 27, 2007, 11:54:32 AM
Hi all,

I\'m having a few issues with the boost on my FD.

Bascially when I boot the car I\'m seeing 0.5 bar of boost up until about 4.5k when the car starts to kangaroo a little, it feels like the second turbo is trying to come on but then almost like it CBA and backs off :Tongue1

The car doesn\'t seem to want to rev to the red line either, in neutral it revs to the lower limiter quite happily and is exceptionally smooth :)

So far I\'ve checked all the main intercooler pipes, these are now ok.  I\'ve noticed that the vacuum chamber is leaking somewhat and am getting a new one off a member on here (money on its way tonight :D)

Would the vacuum chamber cause this or is it likly I\'ve got another issue hiding away somewhere?

Thanks!

Dave
Title: Boost issues
Post by: Fish on June 27, 2007, 12:14:16 PM
Check your plugs and leads. Sounds like an ignition breakup.

Fish
Title: Boost issues
Post by: Hayward North on June 27, 2007, 12:14:45 PM
Think your on the right track with the vaccume chamber, you wont belive how much that leak increases when your under load.
Title: Boost issues
Post by: ds2000 on June 27, 2007, 01:47:49 PM
Thanks guys :)

Fish, that wouldn\'t explain my low boost would it?  Reading around here I am about 0.3 bar down?  The leads and plugs are getting on a bit but when the car is in neutral she revs freely, starts hot and cold.  I\'ll keep it in mind though :)

Re: the vacuum chamber, the nipple that goes into it had broken off and a t piece with sealant was put in there in its place, looking at the T-piece I can rotate it freely and the other nipple on it wasn\'t blocked off properly.

Thanks again

Dave (slowly learning how this wonderful turbo system works) :)
Title: Boost issues
Post by: ds2000 on July 09, 2007, 09:11:54 AM
Well the new vacuum chamber didn\'t cure her, although she does drive better now :)

I\'m still about .3/.4 of a bar down but now I can hear the boost whooshing out somewhere - bah!  I\'ve checked the main pipes and they look ok so I think I\'m going to have to try jacking the rear of the car up, putting her in gear and revving her to locate the leak (if the tubbys will work with the car being jacked.... hmmm)

The joys of this lovely TT system :)

The worst part of this is that once I\'ve got her 100% I might have to let her go, having just bought a house the extra cash would be very handy :( - even just driving her at the weekend without the tubbys being perfect I was grinning away and looks the thing gets - simply awesome! I love this car :(
Title: Boost issues
Post by: leon on July 09, 2007, 02:01:37 PM
the pipes i found which caused my problems  were the ones on the left hand side (above the turbo\'s) i didnt manage to pull a single one off without it breaking into multiple peices my hand! (small vac pipes) :Hammer

But generaly make sure the IC\' pipes are all on etc. ive read a lot of people from seach\'s in the past, people having problems with them. I also had my \'elbow\' slightly ajar after refitting all the vac pipes it was sitting on the rubber seal on the throttle body and was getting a woosh, on first turbo but nothing on second.
Title: Boost issues
Post by: ds2000 on July 09, 2007, 02:51:00 PM
Thanks, all the vac pipes have been replaced so its not that.

I\'ll recheck all the elbow/IC piping too, I\'m thinking it could even be the UIM as I only used liquid gasket when I put it back on :)

Its not all doom and gloom, I drove the car to the MOT station 3 weeks ago and its the first time it had moved in 2 years, she passed straight away, oil sites at 75 degrees on the motorway and about 90 degrees in town, water is 75 and 85 respectively, so it sounds like the rest of her is very healthy indeed :)