Mazda Rotary Club

So the snow has finally melted off my car. So I thought I\'d address or at least try and address the hesitation problem i\'ve been having with my car. I set about the eaths first. I couldn\'t find an earth on my battery. So I geuss I need one! There was a home made looking red wire going from the possitive terminal  into the bulkhead on the passenger side. I figured it was best left alone sinse I didn\'t know what it was. I then took off the earth wire between the engine and the bulkhead and cleaned it up with emery cloth (I also resistance tested it to double check it was ok). Now this wire also looked in my opinion homemade. The spade connector on the bulkhead end had melted the plastic that surrounded it.
Anyways whilst I had the intercooler off I thought i\'d do a bit of cleaning as there was quite a lot of oil residue everywhere. Whilst cleaning and looking for the sourse of the oil I came across 2 hoses that looked like they should be attatched to something (see pic below). They are at the back of engine below the intercooler near the throttle cable.



Number 1 I figured went to the nipple it kinda pointed towards so popped it on there. Its not a tight fit at all but I didn\'t have any clamps for it (I\'ll sort a clamp out soon). The other one (number 2) I can\'t figure out where it goes. I can\'t see a nipple or anything for it to go on.

After I put it all back together I took it for a drive and the hesitation was still there but not as bad. It did seem to get worse on the way home (a few miles later). The hose I reconnected may have come back off or may be drawing air in I think.

So my questions are
1/ Does my battery need an independant earth from the negative terminal?
2/ What are the 2 hoses that I found?
3/ Could they be causing the hesitation at 3.5-4K rpm?

Sorry for the long post but I would like to get this sorted now as its doing my head in a bit.
Cheers and Happy new year!

It looks like Hose 2 should be on one of the nipples on the back of the throttle body.  Is that middle hose broken off ?
 
I can take a piccy of the back of the throttle body (as it\'s out of the engine at the mo ;) - and tell you what was plugged in what.
 
There is a vac line that goes to a 1 to 4 way spider for the oil injectors, 2 vac lines that go to each pair of fuel injectors, and a water line to the wax thermo thing from memory.
 
As for hose 1 - it will be one of the above hoses.

Prof if you can get a pic that would be a big help. I think Number 1 went to one of the fuel injectors. Which would explain the hesitation as thats when the secondries kick in but number 2 I couldn\'t trace without taking the UIM off.
In the pic there is a 3 hoses on top of one another. the middle one and bottom ones were fine buy the looks of them so I left them alone.
Thanks again Dave I\'ll buy you a beer at RS7 for this.

Ok Ade,
 
Here\'s the pics:
 
The first pic is a closeup of the rear of the throttle body showing the vac nipples.
 
There are 4 nipples - top most and the third nipple down are bleads for the fuel injectors - see the lim piccy for where they go to
 
The 2nd nipple is for the vac spider - it\'s a 1 to 4 way converter thingy - see pic - the 4 smaller lines feed each of the oil injectors.

Forgot to say - the bottom nipple - that goes through a one way check valve to the valve on on the wax thermo pellet device - wasn\'t sure if you could make that out from the piccy.
 
Basically if any of the top three pipes are off at all, you will have a vac leak, and more over, if the oil injectors one is off, the car won\'t be getting the lubrication it needs. :2eek

Ah looks like they are the fuel injector bleads then. Good to know. I\'ll have another look at it once I get chance and let you know how I get on (probably have a few more questions too!). Thanks again Dave for the help.

No worries - it\'s a lot easier to see what\'s going on when they are off the car ;)
 
If you need other pics - not promising I still have the bits on my car - I wil see what I can do.
 
Dave.

Cheers. I\'m just wondering how long these hoses have been loose or off all together. I new I had a vac leak but it sort of came and went when it wanted to. like a lot of problems with these cars!

Well I got round to looking bat these problems today. I got the 2 hoses back on and clamped so they shouldn\'t come off again (famous last words!):Giggle. And I made up a couple of earth straps. One from the negative battery terminal to the chassis and I replaced the engine to bulkhead one. I still need to check the ECU for an earth though and fit one if it doesn\'t have one.
I took the car out for a good run and the hesitation seems to have gone:3gears-rh. It has however been replaced with a missfire type problem. similar revs (3.5-4.5k) @ WOT of full boost. It seems ok if I am progressive with the throttle. When I got a clear bit of road to try it propperly I was getting 14psi on my boost gauge maybe a tiny bit more:eek:. So im thinking im just getting way too much boost for my stock turbo/intercooler to deal with. Good job I didn\'t sell my HKS boost controller after all. Im gonna fit it next weekend hopefully and fingers crossed it\'ll cure the problem.
Can anyone tell me what it feels like when you do get too much boost when driving? Mine just kinda seems to miss a little then pick up again. With a few3 pops and bangs.

The rear rotor fuel cut - which is the \'overboost\' fuel cut normally kicks in at 8.8 psi or there abouts - but it will switch itself out again if you leave your right foot firmly planted at WOT - it basically just try\'s to dump fuel in at that point.  It seems like that\'s what you are getting based on your description - but not at those high boost levels - are you running an FCD Ade ?  If you are, you\'ve probably topped that out as well :Giggle:Giggle

Yeah I am running a FCD. It\'s been on the car since 2003 or so. Its never given me any reason to question it before so as far as I know its working fine. Never hit fuel cut before untill now. I also have a manual boost controller that was installed around the same time as the FCD (both by a previous owner) which is turned down as low as it will go and I never mess with it. Any ideas why I would be getting overboost all of a sudden?

Oh and what do you mean exactly by "Topped it out"? I have reached the maxium of its working potential?

Yes :) - you caining that poor turbo man :spank
 
What type of FCD is it by the way - some of them just delay the onset of boost cut - some actually just clamp it at a fixed level - so the error in fuelling just gets bigger and bigger.
 
If you have the first type - you might be getting fuel cut from boost as I noticed in your siggy you\'ve got a stock ECU back in.

Yeah Im back to the same set up I bought the car with. It worked fine back then so something must have changed to cause a problem. Im saving to get my PFC installed + mapped. Pip\'s gonna do it for me but its £350 - a diff I gave him a while back. As for the FCD, I have no idea its an unbranded item just a little black box. Maybe I should get that HKS one of L1am.

oh btw, the fcd in my fc is a little black box also.

Whoah I didn\'t think the stock turbo could get that pressure lol I don\'t push mine that high and mine is fully uprated lol

Yeah tell me about it! Brown underpants time.

Im wondering if the wastegate is sticking and not allowing the pressure to get away quickly enough.

I had a few idle and hesitant issues with the white one in its early days and that ended up being the FCD. Disconnect it for now and see if the issue goes away. Mine was unbranded.

tiddles, the black box one might be a Knight sport fcd as that is same as ths KS ones i\'ve seen. the stickers can come off due to heat in the bay?

Time for an update.
The FCD is working. I now know what fuel cut feels like! Not good.
I fitted my HKS EVC2 boost controller Now I thought I was on too a winner but after taking it out tonight and setting the boost as low as the controller would go I was still seeing massive boost pressures. And in the black of night the turbo was glowing red. It smelt of hot oil not good. This is all within a 1/2 mile or so run and 1 boost of the turbo. Now if I am carefull witht the throttle the turbo boosts well right through the rev range @ a max of around 10psi. But if I am more agressive it over boosts and pops and bangs like fook. I have come to the conclusion that my turbo is knackerd it has got some shaft play that I find a bit exsessive. But why is it getting so hot so quicky and why is it overboosting when I havent changed the set up of the car? Could the actuator have failed and its holding the boost because of this?
Any advice would be greatly received.
Ade

out of interest - has the bar fallen off the bottom of the wastegate ??

when i did some exhaust work on mine - i managed to knock it off ( and the new owner did aswell )

i have NO idea what it does - but worth checking :D

That does sound like a classic \'boost spike\' issue.
 
If you throttle up gently, you\'re giving the wastegate plenty of time to open, so the excess gases can pass by the turbo without a problem.  When you hammer it, you\'ve a lot of gas suddenly trying to get out into the exhaust and the stock wastegate is being overcome.
 
Do you get boost creep ?  Is the car boosting higher and higher in the upper gears ?
 
Is the wastegate ported ?
 
If not, you may need to restrict either the exhaust or induction to keep the turbo from overboosting.  I had very similar symptoms to you when I went over to the HKS mushroom and did my custom inlet ducting - the turbo was able to breathe so much more easily.
 
A boost controller (manual or electronic) won\'t help in a situation like this - the problem is the wastegate is too small, so you either need to port the wastegate or limit airflow in/out to prevent it.
 
Good article here on 1300cc.com :
 
http://1300cc.com/howto/how2/creep.htm

My stock turbo boosted to about 12psi on the 5psi wastegate spring, get the turbo ported before you lose the engine.

Also a glowing red turbo would signal higher EGTs caused by the mix running way too lean, stay off boost until you have sorted this I think.

Quote from: m1tch;670325Also a glowing red turbo would signal higher EGTs caused by the mix running way too lean, stay off boost until you have sorted this I think.

Don\'t worry I am. Too scared of breaking something expencive.

I have no idea if the wastegate is ported or not. I\'ve never had it in bits. I suspect it is as the previous owner that did the rest of the mods and had the engine rebuilt seems to have done things by the book. Ro-Technics did the rebuild and mods for him. If it hasn\'t been done I will do it myself when I strip the turbo out. Im not sure if its worse in the high gears or not. I backed off cause I got scared!

And as for the bar on the wastegate. Hmm im not sure I can\'t see from the top cause of the heat shields but I\'ll have a gander over the weekend. It could be something like that cause it did just happen overnight. It would make sense thinking about it. I hope it is something like that. Easy fix and cheap!

i could only see mine from underneath - so try that :D

Well guys the bar between the wastegate and the actuator was all connected up so I guess its not that. Could it be that the actuator has failed and isnt opening the wastegate or could it be a faulty pressure sensor? It\'s really begining to bug me this problem.

Let me know what you need as you can have a wastegate actuator and I have a boost sensor if you need that as well. Does the turbo only get red after boost or does it get extremely hot while letting it just tick over for long periods. Its quite hard to get decent boost when not moving as its the load that brings the boost on full.  Might be worth deeing if the oil is getting to the turbo. best disconnect at the turbo and see what sort of flow you get after pulling the main egi fuse. This would not explain the high boost levels though.

It\'s only after its overboosted. Normal conditions its ok. I drove it home after my test run when I notice the glowinmg and when I got back it was fine.
Thanks for the offer Pete I\'ll give you a shout if I need anything.

i have a boost thing that the fcd plugs into aswell ( if you need to test it )

So thanks to Mitch I now have a second hand turbo to replace the one that is on my car. So today I set about porting the wastegate on it to try and eliminate any boost creep like I have been getting. Here are a few pics so you can see the enlarged ports.

Stock ports.
(http://i215.photobucket.com/albums/cc308/adereed/StockPorts.jpg)



Ported............. ports!
(http://i215.photobucket.com/albums/cc308/adereed/Portedports.jpg)

Side view so you can see the back of the port cut away.
(http://i215.photobucket.com/albums/cc308/adereed/Photo0546.jpg)


So now all that is left to do is install the turbo and give it a whirl! I\'ll keep you posted.

Thanks again to Mitch.:cheers

Nice bit of porting work there ;)

Well taday me and a mate set about swapping the turbo out for my replacement one. Big thanks to Ash for helping couldn\'t have done it without him. 5 hours it took us, which I don\'t think is bad considering we did it on the side of the road! Was a really fiddley job to do but we managed with only one real issue. A damaged gasket on the water feed pipe. So after scraping it off with a stanley knife blade and making a new gasket it was replaced and it seems ok.
So after taking it for a 15 mile or so drive all seems well. No leaks i\'ve noticed yet (fingers crossed). The boost is still quite high, around 12psi at its worst/highest but it soon settles down and it isn\'t causing the car to hesitate or missfire. So it seems like its solved my problems. It also seems smoother to drive somehow (maybe just in my head!) like its just dealing with the gasses better. Wahoo for porting!
So the next question is how come my boost controller doesn\'t seem to be able to turn the boost down?


Oh big thanks to M1tch for sorting me out with the turbo and thanks to Prof for letting him clean it up when he was supposed to be helping you out!

The boost controller willl allow you to control how quickly the boost builds, and should allow you to make higher than spring boost, but you can\'t turn down the boost with it.
 
The lowest boost the car will make is determined by the wastegate spring / porting / and how easy gas flows in the compressor / turbine.
 
Putting a restriction in the exhaust reduces max boost, likewise restrictive intake will do the same.  If you take the stock engine, modify the air induction and sling a big old zorst on it you will make a lot more boost than the stock 5-6 psi the wastegate spring would normally do.

Ok I see. Just I don\'t really notice any differance when I alter the settings on my controller. Its an old school one that you tweak a screw in the back of to set low or high and then select on the front of the unit which you want to use. It also has a manual setting knob on the front for quick alterations. I have more of a mess with it and see if I notice anything. Car certainly does feel differant in a good way. Roll on Rotorstock!

Did you check the clearance of the flapper on the exhaust flange? Prof has got his spaced out using a cut down spacer and I have a custom bell mouthed downpipe to allow the flapper to open fully, might be worth you taking the downpipe off as well as that plate on the back of the turbo, then grind it down a bit. The plate at the back only allows the wastegate flapper to open a tiny amount, it then gets jammed on the plate meaning it can\'t open more.

Im glad the turbo is ok ^_^ its been mitch cleaned, so its worth an extra 20bhp ^_^

Yeah I noticed the flap doesn\'t open a huge amount as it fouls on the back plate. But I know with water that type of valve lets through something like 90% of its max flow at around 20% open. Its something like that anyway.
I don\'t think I\'ll be taking it off again to modify it. Well not in a hurry anyway unless I have more problems. The porting seems to be doing the trick for now.

Quote from: TiddlesRX7;679000Yeah I noticed the flap doesn\'t open a huge amount as it fouls on the back plate. But I know with water that type of valve lets through something like 90% of its max flow at around 20% open. Its something like that anyway.
I don\'t think I\'ll be taking it off again to modify it. Well not in a hurry anyway unless I have more problems. The porting seems to be doing the trick for now.

Good good :) well if you do have issues, its just a case of unbolting the downpipe, unbolt the back plate and see where the flapper is hitting the plate - usually scratch marks in the carbon, just grind it out a bit, but it is pretty amazing how it is find on OEM boost and OEM control!

Did you get an uprated actuator in the end?

No not yet. Thats the next stage of my plan along with the apexi install and map (only been waiting a year now to find funds for that!). Oh and the purchase of an uprated top mount ;)

Quote from: TiddlesRX7;679076No not yet. Thats the next stage of my plan along with the apexi install and map (only been waiting a year now to find funds for that!). Oh and the purchase of an uprated top mount ;)

Yes yes ok ok, I will get about changing my intercooler setup :rollin