vtecgsr95

I bought my FD a few months agon, and after backing it off the trailer it was transported on, I found a small turbo coolant line leaking. After tearing into as far as I did, I decided it was time for all the hoses to be replaced and a silicone vacuum job. I did all of this among other small maintenance items, and finally got it back together last night! Now, I dont have a midpipe installed right now, so first impressions werent the best at idle!! The car started up and ran very well, pulling about 14-16 inches of vacuum at idle. Took it out and have a Turbo XS MBC turned completely off......and boosted 10-8-and spiked close to 15 and I let off!! So here are my questions (I did port the WG already):

1: Isnt it only supposed to boost like 6-8 psi with a MBC shut completely off?
2: What is an acceptable vacuum reading at idle if idle is around 800 RPM's?
3: Is my secondary turbo spiking cause I have an open DP or do I need a MBC for each turbo??
4:I have burped and filled the coolant to the max and the low coolant light is still on! What gives??

The car seems to run very well, and starts fine hot as well. I just wanna make sure I get everything right before driving very far. Thanks for any help!

Frank

Herblenny

iTrader: (13)

1. How did you hook up your boost controller?

2. I think your vaccum seems good at idle

3. It shouldn't spike to 15lbs because of DP.

4. You might of pull out the wire to coolant level sensor. Check the wiring.

My Guess is that when you replaced all the lines, you also repaced the line with the pill. Also not knowing how you hooked up the MBC, its even harder to guess what might of went wrong. Also, double check your lines. I had one of my line melted and I spiked to 20+lbs of boost.

vtecgsr95

OK, I have the boost controller on the line closest to the firewall......its the shorter of the 2 vacuum lines. When I talked to pettit racing, thats the line he told me to tap into. If you look at the simplified vacuum diagram which I am using, its the short green line for wastegate control. I have checked all other lines and connections and everything is good and tight.

On the coolant level sensor, is it the one that goes on the front of the filler housing? There is a 1 wire sensor plugged in there and the wiring on it is fine! It was on when I bought the car, and I have repaired the leak and its full now so I dont understand! Is there another wire that could be affecting this? I did remove the air pump and a/c compressor.....not sure if there is anything related that needs to be grounded or anything like that?

Herblenny

iTrader: (13)

Is this the controller you have?



IF so, see this chart

spooledUP7

When the car is cold is the coolant to the top of the filler neck? It's possible that you still need to burp and add more coolant.
The way the level sensor works is by grounding via the single probe contacting the body of coolant. You can test its function by unplugging the connector and checking continuity to ground with a multimeter. I don't think it will read down to zero, but you should get some continuity nonetheless.
Alot of times the wire gets broken right where it enters the plastic end of the sensor, and usually causes a bunch of green and white chalky funk to grow.
The sensors are cheap. In fact I think it is even cheaper to buy a second gen sensor, but you will have to transfer the harness connector.

vtecgsr95

I have the HPBC which is similar, but has an extra adjustment. According to this pic, I need 2 boost controllers?? I was under the impression 1 was fine! Maybe if I bypass the wastegate control solenoid and just use the MBC that will work fine?

One more question......after using the sought after "search" function, I found that I needed a 29" and 35" belt for removing the air pump and a/c compressor. I got both of those and neither would fit! I ended up using a 36" on the p/s and cannot find the proper belt for the alt/water pump! Any help here???

rynberg

You can't bypass the wastegate solenoid with a MBC...and you don't need two boost controllers.

You are going to have extremely high boost without an exhaust hooked up!

Perhaps you should learn a little more about how these cars work before you blow an engine!

vtecgsr95

OK, why even waste the time to post that comment......especially if you are a moderator? Why not try and help me LEARN!! I have searched everywhere and there are some running with just a DP with no problems!! I never understood why people waste their time criticizing others when they could spread the knowledge instead??? Guess you dont have to do that if your a moderator.

So back to the topic, you say I dont need 2 boost controllers, but dont elaborate from there....OK, that helps a lot!! I just wanna make sure its hooked up properly and I AM getting a high flow cat this week so you know.

Any thoughts on the belt issue would be appreciated as well. thanks!

dgeesaman

iTrader: (7)

When you say you don't have a midpipe installed, do you mean you still have a stock cat and cat-back installed? If so, then you did nothing wrong since you still have the main cat and cat-back providing some backpressure. The spike is probably caused by a disconnected hose between the wastegate solenoid and the actuator, or the line from the primary compressor to the wastegate actuator.

If you mean you have no exhaust attached after the downpipe, then you're running something even more aggressive than a dp+midpipe+cat-back combo - you're effectively running a dump pipe. If this is the case, and you went out and boosted on the test drive, then yes you need some remedial help, and Rynberg's comments are spot-on. Running without any cats (or even piping) means you better know what you're doing.

Dave

TpCpLaYa

iTrader: (10)

yea do not touch boost untill u have a full dp,mp/cat,cat back.

thats the problem u have

rynberg

Your earlier posts indicated you were running an open downpipe...as in no cat or cat-back exhaust hooked up. If that's not true, you should learn to communicate better....and you should not have high boost problems with a downpipe/stock cat/stock cat-back scenario. If it is true, then no boost controller is going to help you.

You don't need two boost controllers, you only need a controller on the wastegate. Some people choose to run a second controller on the pre-control line to help adjust the transition. It is very easy to mess up the boost pattern completely doing this, and in general, it's not recommended.

You say you closed the boost controller all the way? This would result in overboosting! The wastegate solenoid needs to see boost pressure to open. If you want to run off of wastegate pressure (7 psi), you would need to have the controller wide open.

Your idle vacuum is a bit low for a stock-ported motor.

vtecgsr95

OK, guys, lets start out fresh again and forget tha last posts. I do want your help and I am trying to learn how to care for my car properly.

Hi, I have a 1993 rx7. My mods are 3" DP, gutted stock midpipe/cat, and corksport 3" catback, ported stock WG, XS power I/C . I also have a pettit unlimited ecu, removed a/c and air pump, running the simplified sequential setup. I installed a turbo XS HPBC manual boost controller. I am running it between the wastegate control lines which are on the red MBC in the pics above. My problem is that when I take off
a: sometimes the second turbo doesnt kick in at all
b: sometimes I only will get about 4 psi on the primary and no secondary boost
c: when I get good boost and proper primary to secondary changeover the boost spikes to 14-15psi -maybe more, but I let off before it gets any further.

Sometimes shes fine aside from the boost spikes. I wanna make sure I dont have the MBC in the wrong place as far as the vacuum lines are concerned.

I am thinking there must be an issue with a solenoid not working properly or something to cause the other issues.....car runs and drives great though and starts immediatley hot or cold. Any help is greatly appreciated!!

vtecgsr95

Another update: Not sure if they are all that way, but sure seems to idle pretty rough when cold.......and after coming down from a rev.....seems to idle rough before settling.....maybe normal with this vehicle and all the smog items removed.

And, today I cant get more that 4 psi......tried several times and in all gears....nothing more. Checked all lines....everything is on tight. I am starting to get a headache!

vtecgsr95

No more help?