Boost Issue

[MAPSVO]

I have driven my 86 now for 35 miles since engine overhaul and car assembly. I got the car in pieces and had never driven it. I have been taking it easy on the power since it was real fresh. My boost switch lights up when it is in the premium position and the BCS is hooked up.

I noticed that I could get past the lower boost limit and today I got after it a little and it boosted all the way to the top of the red, no bad results I was watching it and quickly got off. ( It runs damn good by the way).

So, I either have a wastegate actuator that is not working or possibly the BCS. I was thinking I could isolate the problem by bypassing the BCS, I figure it should only boost to 9 PSI or whatever these actuators are set to.

Is this a reasonable plan? Does anyone have any suggestions of a different way to run this problem down?

Thanks in advance

Mark

[Stinger]

To test the actuator, simply blow into the hose that runs to it with your mouth. If you can blow through it, it's junk and needs replaced (assuming there isn't a hole in the hose you're blowing in).

Your plan of action is a good step in diagnosing whether the BCS is hooked up and functioning correctly (again, assuming all the hoses are in good shape).

If you can't blow through the actuator and bypassing the BCS still results in uncontrolled boost, I'd take a real close look at the wastegate flapper door/lever assembly. It may be stuck/rusted shut.

[MAPSVO]

Waste gate is good and free and not rusted, was cleaned/beadblasted/inspected when I rebuilt the turbo. I did put air pressure on the actuator to test it before I installed it and it did work. I did not measure the pressure but was easy on it and used regulated low pressure, my gauge at the regulator is not that good, and hard to read. The lines to the BCS are new however I am not sure if they might be reversed if it makes a difference. I will proceed and report back with results.

Thanks

[MAPSVO]

I did some testing this morning. All the lines were clear and in good shape. I unhooked the BCS and drove the car, still has a overboost condition. I suspect now that I am in for a wastegate actuator replacement. Later after this thing cools down I will take a look at the attachment of the rod end to the wastegate and put some air pressure to the actuator to see if it moves.

If it turns out to be bad, how much pain is it going to be to change that thing without removing the turbo? Also I have been looking on Ebay at actuators, anybody have any suggestions on a good source?

And now I'm going to the lake!

Mark

[GLASSMAN]

Waste gate is good and free and not rusted, was cleaned/beadblasted/inspected when I rebuilt the turbo. I did put air pressure on the actuator to test it before I installed it and it did work. I did not measure the pressure but was easy on it and used regulated low pressure, my gauge at the regulator is not that good, and hard to read. The lines to the BCS are new however I am not sure if they might be reversed if it makes a difference. I will proceed and report back with results.

Thanksno more then 20lbs of air preasure , , you should feel the rod move that opperates the actuator when you apply the air preasure

[Stinger]

As stated above, you don't even need to use air pressure to test the actuator. It can actually skew the test because if it's a small tear in the diaphragm your compressor can have enough volume to move the actuator rod while leaking. Just blow in the hose with your mouth. If air blows through, it's junk. If you can't blow through it, it's good. Just don't let anybody see you do it or they may wonder just how much you love your SVO ;)

It is pretty difficult to swap out on the car because you have to unbolt it from the bottom side of the turbo. It is doable but not fun if you don't have small arms to reach the bolts.

[MAPSVO]

Well, now I'm confused for sure. I attached a longer hose to the actuator and blew, could not blow through, actually with a jaw busting pressure I could feel the actuator just begin to move. next I attached regulated air at 10PSI, actuator arm moved and opened a bit, moved the pressure up to 20PSI and it opened more as expected.

I don't know what to make of it now. I think I will attach a different gauge to the system and drive it, maybe I have a crazy gauge.

I have a manual boost controller, can I just install it in place of the BCS using the same hoses, or does it need to be hooked up differently?

Also should you hear the BCS do something with ignition in on position and the switch turned to premium or the other way?

mark

[GLASSMAN]

if you can blow hard enough to move the actuator , you need to switch professions. no one that i know of can suck or blow out 20psi .if they can i sugest the porn industry. if the actuator rod doesnt move , its stuck and needs to be cleaned out , if it moves and travels freely no sticky spots then it good,. youd hear an air leak if it was leaking at 20psi no matter how small it was and it would get bigger fast if there was a leak with 20 psi constantly flowing thru it .

[MAPSVO]

Ok, aside from the porn thing, I got to thinking. Eventhougth regulated pressure would move the actuator, I did hear a blow by or hissing sound. I just put the same regulated air to a couple of actuators for 84 Turbo GTs I have as spares guess what no hissing/blowby. As a matter of fact with tight connections and no leaks the rods will stay extended until you let the pressure out. The actuator on the SVO will not do that.

I guess the volume of air is enough to make it work when hooked to the shop air but the leak is big enough and the restriction in the factory fittings is small enough that it won't work on the car.

So now I am in the process of replacing the actuator with one of my Turbo Gt ones. I will use the manual boost controller and do away with the stock boost control system. I think the actuators for the Turbo GTs are a lower pressure than even the regular setting on the SVO. Those cars don't have gauges just little green lights so I don't know what pressure they will maintain.

I might run the lines inside the car and mount the regulator inside the console lid.

[MikeFleming]

I guess the volume of air is enough to make it work when hooked to the shop air but the leak is big enough and the restriction in the factory fittings is small enough that it won't work on the car. ANY leak == Bad. Replace.


I think the actuators for the Turbo GTs are a lower pressure than even the regular setting on the SVO. All T3 actuators on the Ford 2.3L EFI turbo engines are the same, except the IHI units. Nomjnal 10.0 ( +/- 0.5) PSIG opening point.

[GLASSMAN]

if you hear hissing then something is broken, try the feed line first then retest. the actuator diaphragm may be torn and if so every thing has to come off again. get a new turbo gasket kit and if you can find them , new turbo nuts for a 87-88 turbo coupe. dont run your adjustable valve to the console lid, if you are going to relocate it to the inside , put it in the ashtray area or dill a hole in the console by the clock and mount it there, ive seen them under the dash close to the hood latch handle and hated it. it you make a plate for the ashtray area , you can hide the adjustable valve where it will never get bumped or messed with by anyone who doesnt know what it is



i did this same test proceedure on my old 84 , found the the feed line was cracked and the actuator was stuck, replaced the line and retested with 16psi and it moved very little released preasure and did it again and it moved a little more a little faster , repeated this several times then pushed it up to 20psi, it moved to where it moved to at 16psi but didnt return rite away when air was released , so i hit real fast and let off and it popped closed. repeated this several times until the actuator moved the rod smooth and consistant with 18-20 psi. it took me about an hour to get it to go smooth or make me happy enough with its opperation

[GLASSMAN]

ANY leak == Bad. Replace,

All T3 actuators on the Ford 2.3L EFI turbo engines are the same, except the IHI units. Nomjnal 10.0 ( +/- 0.5) PSIG opening point.

thankyou mike, ^ WHAT HE SAID^

[Alex L]

All T3 actuators [...] except the IHI units.

i see what you did there. :stick_poke:

[MAPSVO]

Actuator changed on the car. Lucky my turbo is real fresh and not all stuck. I took the drain line off, got the clip off from the top side, I also loosened the bolts that hold the compressor housing on and was able to move it around some to get better access. Not too bad at all. was able to do most of the work from the top but had to go underneath to tighten the oil drain line and put the c-clip back on.

The old actuator for sure has a leak through the diaphram, not so much as shop air won't work it but too much for engine air to move it. A big difference in travel of the rod on the old vs. the replacement. I suspect all is well now. I am going to hook the stock BCS and see what happens.

Did not need any new nuts or gaskets and don't care to hack up my console either. My first SVO had the controller under the lid of the arm rest, I kind of liked it there thank you.

[MAPSVO]

We B havin boost, not too much, not too little, just like baby bears soup!

First time to test it out. Everything works as it should.

Thanks Mike and GLASSMAN !

[MikeFleming]

Party On, Wayne!

[SVOTim]

Sweet!

[mrzw70]

Glad you got it sorted Mark.