Mazda Rotary Club

Cars by Model Type => 2nd generation RX-7's => Topic started by: johnf on June 28, 2010, 04:51:41 PM

Title: MOT passed - but...............
Post by: johnf on June 28, 2010, 04:51:41 PM
It might sound a bit strange but drove the T11 for the first time today, to the MOT station where it passed.

This is the first time since Oct it\'s been driven and of course has the replacement engine.

When I bought the engine I was aware that the turbo was shot but I had another one from the original engine which I believe to be ok so I swapped it for that.

However I have no boost and a some smoke.

So where to I go from here, is it time to get it down to Carl or are there things I can do / check first.

Seems to run ok, starts hot & cold.

Fond other unconnected multi-pin plugs [pic] any idea what these are?

Apart from changing the turbo the only other thing I\'ve done is the air pump removal.


Thanks
Title: MOT passed - but...............
Post by: 1990_fc3s_t2 on June 28, 2010, 05:22:44 PM
maybe your wastegate clip has come off and it just stays open? I think the green connector is the fuel pump jumper, the other one i thought was the afm plug but dont think it would run not connected unless your standalone?
Title: MOT passed - but...............
Post by: johnf on June 28, 2010, 06:07:00 PM
Trying to find something obvious and the arrows on this look to be pointing the wrong way.
Title: MOT passed - but...............
Post by: dthebuk on June 28, 2010, 06:11:26 PM
pretty sure the green clip is for fault finding, mine isn\'t clipped into anything either
Title: MOT passed - but...............
Post by: Prof on June 28, 2010, 06:43:40 PM
Yep - the green clip is a test clip - not sure about the other one.
 
The arrowed thing is the Recirc - so it should be coming from the turbo to intercooler pipe and going back into the intake - that\'s the direction of flow - can\'t really tell from the pic but I reckon its in the correct way.
 
As to the turbo not boosting - dthebuk may well be right - my actuator arm fell off and you get next to no boost at all.  You should be able to see if it\'s come off without taking it all apart - if you\'ve still got the heatshield on, undoing the top 2 nuts will probably free it up enough to get a look in there.  Those pesky circlips come off all too easily.
Title: MOT passed - but...............
Post by: pdtaylor18 on June 28, 2010, 08:49:45 PM
If that was the original turbo then it was a good turbo but who knows what that fool did to the car anyway. Smoke can not be too bad if it passed the MOT and especially without an airpump or CAT.
My sort of MOT station.
Worth a look at that wastegate clip and if its come off then buy a brand new one as they do suffer from heat and corrosion down there. That white plug does nothing, not sure what it does but i am sure that was free for me as well. Remember that this car has a S5 loom throughout even though its a JDM car.

Congratulations on it passing.
Title: MOT passed - but...............
Post by: johnf on June 29, 2010, 07:38:41 AM
Where does the boost gauge get it\'s reading from?

Is it like the FD, being air fed?


.
Title: MOT passed - but...............
Post by: Brett on June 29, 2010, 07:51:16 AM
The boost guage (assuming it\'s the stock one) is fed from the senor mounted on the suspension turret near the air intake.

I think grinder had the same problem a few years back, it\'s a fairly simple fix provinfing u don\'t mind the odd skinned knuckle :)
Title: MOT passed - but...............
Post by: Prof on June 29, 2010, 07:53:46 AM
The stock boost gauge is electronic - it tee\'s off the boost signal from the MAP sensor.
Title: MOT passed - but...............
Post by: m1tch on June 29, 2010, 09:08:06 AM
It might be an idea if you aren\'t running an aftermarket gauge, to run a mechanical boost gauge as the car might be boosting, but the gauge might be at fault.
Title: MOT passed - but...............
Post by: grinder on June 29, 2010, 09:50:02 AM
my wastegate arm popped off - but it did it when i was changing the down pipe - so probably my fault !! LOL

if i can remember tonight i will pop the bonnet on mine and have a look for the white plug thingy

i take it that you have a boost controller on there .. is that reading anythign ?
Title: MOT passed - but...............
Post by: johnf on June 29, 2010, 10:24:07 AM
No boost reading at all and driving it to and from the MOT it didn\'t seem to have any get up and go.




.
Title: MOT passed - but...............
Post by: Prof on June 29, 2010, 11:36:39 AM
Quote from: johnf;701872No boost reading at all and driving it to and from the MOT it didn\'t seem to have any get up and go.
 
 
 
 
.

John,
 
Where does the gauge sit when the engine is off but electrics on, and then when idling ?  Does it show vacuum ?
Title: MOT passed - but...............
Post by: johnf on June 29, 2010, 11:46:06 AM
zero

not + or - and doesn\'t move at all
Title: MOT passed - but...............
Post by: Prof on June 29, 2010, 12:36:04 PM
That means your MAP sensor isn\'t seeing vacuum then - and probably also means the car is running in a limp mode with fixed maps.
 
Check the hose to the MAP - it should ideally be plumbed into the vac nipple under where the BAC valve is.
Title: MOT passed - but...............
Post by: johnf on June 29, 2010, 01:06:08 PM
QuoteCheck the hose to the MAP - it should ideally be plumbed into the vac nipple under where the BAC valve is.

Wish I understood half of that - lol

You\'re forgetting how little I know.
Title: MOT passed - but...............
Post by: Prof on June 29, 2010, 01:31:50 PM
Sorry John :(
 
The MAP sensor is the rectangular black box thing with a small electrical cable (4 pin plug) and a vacuum hose coming out of it.  It\'s usually mounted on the drivers side strut tower - towards the front of the engine bay.
 
If you follow the upper inlet manifold down to where it meets the lower inlet manifold.  If you look from the side of the car, looking at the centre of the manifolds - where they join together - and then follow the join towards the bulkhead - there is a small vacuum nipple sticking out at a slight angle - that\'s a good place to for the hose from the MAP to join onto - as that\'s a source of vacuum/boost.  That\'s what I\'ve got my MAP sensor plumbed into.  I will take a pic tonight so you can see what I mean.
Title: MOT passed - but...............
Post by: afennell on July 01, 2010, 12:33:05 PM
Glad the car is on the road John, I\'m going to try and do the Duxford event as long as my friends rex is back from an engine re-build.

Did you fit the engine your self?
Title: MOT passed - but...............
Post by: johnf on July 01, 2010, 12:38:21 PM
Hi Adam

Fitted it with a fair bit of help form a mate, just hope I can get it sorted for Duxford.

We\'ve sort of arranged to come down for the weekend, so I\'ll see you up the pub.

Glad I wasn\'t around Richard when England were playing.


John
Title: MOT passed - but...............
Post by: afennell on July 01, 2010, 12:50:48 PM
even better, always nice to have a drink.

Dad was surprisingly calm considering.

After 4 months ownership my friends rx7 went pop, its currently down in reading having a re-build, he is after a 16bit power fc as its post 1997 car. Just on an off chance don’t suppose you know of anyone?