newjerseyradcliff

im havin a litttle problem here. its a 93 twin turbo and it seems like i might be having a problem with the second turbo. when i rev the engine up in neutral i can hear the first turbo bov venting. but there is nothing from the second turbo bov. when i hit the gas, there is no suction whatsoever from the second turbo inlet pipe. when i let off the gas, there are gasses coming out of the second turbo inlet pipe. is this compressor surge? it doesent sound like it, but if anyone can help with this it would be greatly appreciated so thank you in advance/ ive ben messing with this problem for 3 days now and cannot figure out what the problem is.

Mahjik

iTrader: (1)

You might want to study how the sequential system works:

http://www.autosportracetech.com/RX-...erOverview.htm

The second turbo doesn't really spool and get used until around 4200 rpms (and some other factors). You won't hear it at idle unless you remove the tube venting the CRV into the stock airbox. Even then, the CRV is open venting the secondary turbo until the the transition point.

Here's a good guide for troubleshooting the stock twin turbo system:

http://www.autosportracetech.com/RX-...leshooting.htm

I would recommend doing the boost test first:

http://www.fd3s.net/boost_test.html

newjerseyradcliff

second turbo is not spooling! also it is blowing out the inlet for second turbo, the charge control acuator opens when at a high rpm and throttle realesed, it only opens when rpm are going down. stays open after that untill back to idle. when it opens it blows from the inlet on cold side of second turbo.

newjerseyradcliff

bump. sorry i need to figure this one out, driving me nutz

johnsti85

no body has any ideas about this? im headen over to the op's house now (about an hour away) to try and figure out the problem. im a mechanic for a living, but ive never worked on a rotory so all i can do is apply general engine knowledge, and i do know a good deal about turbos, coming from a turbocharged car myself. if anyone can help pinpoint what could possibly be the problem, it would be verry appreciated.

Mahjik

iTrader: (1)

The troubleshooting guide is linked above. There's not really much to say but to start working through the troubleshooting guide. Also, the information that people need to be able to provide more help is the results from a boost test which I also linked above.

The sequential system has quite a few components. No one is going to be able to say "this is it" over the internet without more information. You guys need to start narrowing down the problem using the links I provided above.

johnsti85

that was a HUGE help let me tell you. especially from never working on one of these systems before so thank you for that. the thing is, i dont see any of the waste gate actuator rods moving, so thats not normal. secondly, the charge control valve will remain closed untill you rev the gas near redline once from idle. then upon the engine decelerating, the charge control valve will open and stay open untill the rpm's drop back down to idle. and right after the charge control valve opens, exhaust gasses come OUT of the second turbo inlet pipe. there is no suction from the second turbo, but it blows exhaust out. do these cars not make enough boost in neutral to spool the second turbo? if thats the case than why is the ccv doing what its doing? and why is exhaust coming out of the turbo inlet? there is no smoke coming out of the exhaust so its not a bad turbo. i guess ill just poke around with it with george some more today.

Mahjik

iTrader: (1)

Nope. About the most the stock system will generate without load on the engine is around 4 PSI. You need to actually drive the car to do a full boost test.