FORD BA XR6 TURBO BOOSTING PROBLEM...

[Greendaddy]

Hi there needing some knowledge and advice, I've got a 2003 ford ba xr6 turbo auto. I've owned it for around 2 and a half years now and it's always had problems, biggest one is when you put your foot down and hold boost for more than 3 or for seconds it starts to shudder really bad and go into like a limp or safety mode and wants to conk out, only way to stop it doing it is to feather the accelerator numerous times then goes back to normal. No engine lights come up or anything of that sort. I had the spark plugs and Coils changed when I first got it, changed the wastegate, that fixed it for a coupe days then went back to sh*t, changed the wastegate solenoid came good for a few days then went to sh*t again, it started popping and backfiring and over boosting so I changed both map sensors helped it a fair amount but still pops and misses under heavy load and goes into that safety mode again when I hold boost. Really need help and advice on what It could be. Maybe the computer needs a tune or something? Maybe the wastegate flapper isn't opening fully.? It's all stock standard besides a rear muffler delete.. If anyone can help it'd be much appreciated 

[BeerTurbo]

Do you have an actual boost Gauge installed and know how much boost its getting to? if its over boosting the ECU will cut.

 

If its over boosting, you can try run the actuator directly from the nipple on the turbo and bypass the factory boost controller, this should give you a solid 4.5 or so PSI....... if your getting more you might have a faulty actuator/stuck actuator.

[Greendaddy]

Hi mate yeah I have a boost gauge, it's seen up to 22 psi ? I replaced the actuator, the boost solenoid, map sensor, boost pressure sensor. I'll try and run it straight from the turbo to the actuator, would I leave the electrical side of it still hooked up or bypass it altogether? 

[BeerTurbo]

Jesus Christ, is this thing modified? ie ECU and injectors

 

Stock computer and tune wont expect anything more than 7psi and stock injectors will run out of fuel around 11psi........... id says your in dangerous territory getting up that high, dont let it go over 10 if your stock tune.

 

TBH I think its just a boost controller that its connected to, that vac line in question............so run it direct to the actuator and runt he car, if it get anywhere above 8-9psi just back it off, it should not be that high if you have a stock actuator.....if you have an aftermarket one that will be a different story.

[Greendaddy]

Everything is standard except for the rear muffler delete. I'm not sure the history on the car whether it had other mods before and someone tried to tune it... As is though standard everything. Coming up P1227 closed wastegate failed overpressure 

[BeerTurbo]

do that direct vac line thing mate, should not take much time to changeover....like I said back of around 10Psi.

This test should get you the absolute minum boost your config will run.

If you get up to 10 psi with it setup like this, you have an actuator problem, or potentially a stuck flapper valve (if shes stuck she will just boost to the moon and back)

 

mines got a 3inch straight thro exhaust, no mufflers cat or anything (sh*tbox racer) and it sees max 4.8 Psi in this same config.

 

If you hook a vac line from your air compressor, to the actuator and activate it with less than 10psi pressure (use the compressors regulator set right down, regulate it, if you smash like 80psi in there you will bust it up).......you should be able to see the actuator rod move and the flapper open, its ina  *beep* of a spot so maybe record it on your phone.

[Greendaddy]

Had the dump pipe off the other night and put a mighty Vac through the wastegate line and at around 5 psi it started to open it, the flapper looked in decent condition. I've tried just about everything now, losing hope for it. 

[BeerTurbo]

well that's a good sign, bypass the factory boost control and see how you go bro.

[Greendaddy]

Cheers mate will give it a go tomorrow, so just run hose straight from the nipple on the turbo to the actuator.? I'd disconnect the wiring harness for the wastegate solenoid yeah? Sorry for so many questions I'm pretty average when it comes to mechanical things 

[BeerTurbo]

Leave the wiring stuff connected, should not affect anything. 

 

yerp, direct connect, just like this 

 

[Greendaddy]

No worries will give it a try in the morning. None of it makes sense, I changed the actuator awhile ago and it fixed it for a few days then went back to rubbish, I put a second hand boost solenoid in and it worked. Although on reds / accessories it was making a clicking sound constantly I thought it was stuffed too but it actually worked. The original one never made this clicking sound, So I bought a new genuine one put that in and that one also clicked when accessories were on, so I thought it was normal to click. I did some work on the car which it was off road for a few days, punched the broken cat out, engine mounts power steering line drove it home started breaking up through high revs, I've already replaced coil packs and plugs before this, so I replaced both the map sensor and the boost pressure sensor, since then the boost solenoid has stopped clicking and no longer works, I'm not sure if it's just a coincidence or what but it's really got me stumped 

[BeerTurbo]

just think of the solaniod as a really fast on/off air valve.

 

When the car reaches the boost it want - it will open to let air thro, but you can modulate it so it runs more boost (on of on off)...

so you turbo actuator might be a mechanical 4.5Psi spring, but with the controller it can modulate the air in supply to actuator so the car will run higher boost

I believe the Peak boost a BA computer will aim for is somewhere in the 6Psi range.

 

so just think of it like that, mechanically the car will try for 4.5 PSI, but with the use of the boost controller it will try for 6...

with the use of the boost controller you can bring on boost quicker and run like a variable boost through the RPM, the electronics are pretty fancy.

 

so if you boost controller is stuck closed, or not responding correctly due to bad wiring, there could be a limitation on the level of boost sent to the actuator.if nothings sent to the actuator it will over boost like crazy (same as if the actuator was broke (they can leak or if your rear valve was stuck).

 

when you add in a less restrictive exhaust and sh*t like that, all this will happen faster and things will tend to run more boost because the turbo is able to spool up considerably easier than it could before....... but like I said, mines 3inch straight though and can still manage to sit under 5psi, I cant see why yours wouldn't be able to do the same or similar if you removed the computer control of the boost.

Edited 09/06/18 09:57 AM by BeerTurbo

[Greendaddy]

Yeah I see what you're saying. It's all complex just a matter of figuring out why the wastegate is staying closed, the boost solenoid has power going to it I checked that today. But I'll do the bypass tomorrow and see what I come up with. If that fails what next? Haha

[Greendaddy]

Hey mate put a hose straight from the turbo to the actuator still seeing at least 15 psi .... No idea what to do now. 

Still got me wondering what could possibly make the wastegate stay closed and force overboost 

[BeerTurbo]

when you connected your tester to the actuator and it opened around 5 psi, was the actuator leaking at all? like a faulty diaphragm? 

[Greendaddy]

Nah no leaks or anything of the sort, actuator was changed not too long ago. The diaphragm is still good. Maybe take the turbo off and take it to a shop get it flow tested or is that a bit overkill? 

I have no catalytic converter either it sh*t itself so I punched it out to get me out of trouble, any chance this could be causing me problems? 

[BeerTurbo]

Mines got no cat, only straight thro and its fine.

But ive read lots from people saying they do over-boost with free flowing exhausts. but yours seems a bit extreme to me.

 

your issue will be around that actuator not opening the flapper enough - its the only mechanical thing to control boost.

see they offer flapper valve enlargements for these cars, possibly to control your kind of issues...the more air it can divert from the turbine the more solid the boost curve can be.

 

nah, that overkill.....get it flow tested, maybe having the flapper enlarged is a half decent idea.

 

If you want to try extremes...disconnect the actuator from the flapper valve, the use some wire to hold the flapper valve all the way open. then test it.

[Greendaddy]

Ahh yeah makes sense. You wouldn't believe how hard it is to find a standard cat to put back on haha I'll try and get the turbo off and go get it flow tested hopefully somehow that flapper is just getting caught or something. There's nothing else electronically it could be or even mechanical 

[BeerTurbo]

I did a bit more reading, seems anyone who modify s the exhaust on a x6t gets over-boosting issues.

If you going to keep the aftermarket or high flow exhaust maybe look at a larger flapper valve or adding external wastegate.

or go back to stock exhaust

 

I dont know how I got so lucky.

 

good luck.

[k31th]

Check the actuator with a compressor to see if it cracks at the desired pressure. It sounds like you've got a stuck/sticking actuator, especially if it overboosts on connecting the compressor to the actuator.

 

Also, get any 200 or 300 cpsi catalytic converter welded into place because the punched cat will definitely cause it to overboost on a stock car.

[Greendaddy]

It starts to open up at 5 psi. I'm assuming that's good. Trying to track down a cheap standard cat but it's ridiculously hard to find. Is it possible to have a blockage or something along them lines in the intercooler 

[k31th]

You could have a blockage in the intercooler, but it wouldn't cause overboost.

 

Just get any cat (with the ratings I mentioned above) cut and shut into the stock position at an exhaust shop.

[Greendaddy]

No worries will give it a crack in the next week or so thank you. 

[BeerTurbo]

How did you go?

 

Mine ended up with an over boosting problem also, Ba na motor with turbo gear and straight through exhaust.

I ended up installing a J pipe to move the turbo to high-mount and an external wastegate to control boost, 45 mm turbo-smart gate.