Boost Pressure?

[KENCO]

1990 SE, WHAT SHOULD BOOST PRESSURE BE READING?

MINE SEEMS LIKE IT NEVER GOES ABOVE .5, IS THIS CORRECT?

[Malc Holmes]

Its should be going up to about 0.85 ish. You have probably got a non functioning wastegate modulator solenoid. If this doe not open then the wastegate will open at 0.5 bar as a fail safe. Swap the solenoid and you will probably fix the concern. Worked for me and many others on LEF. The solenoid is only about

[pitstoppete]

thats a good one Malc, but,

Mine did this too when i got it. turned out it had a low temp. summer thermostat in it. if they dont get over 72-73 ish deg.C (IIRC) they dont give full boost.

previous owner had thought it was quite fast for three years. clearly was juch better after a new 82 deg stat was fitted...

0.85 is good, occasional just under the 1 bar is also usual, (IIRC)

[KENCO]

MINE MIGHT GO TO .85 BREIFLY UNDER CERTAIN CONDITIONS, BUT LOOKING AT THE GAUGE I THOUGHT IF IT GOES UP TO AND OVER 1.0 IT SHOULD PROBABLY SHOOT UP THERE AT TIMES.

I WILL PAY CLOSER ATTENTION TO IT, AND LET YOU KNOW.

Its should be going up to about 0.85 ish. You have probably got a non functioning wastegate modulator solenoid. If this doe not open then the wastegate will open at 0.5 bar as a fail safe. Swap the solenoid and you will probably fix the concern. Worked for me and many others on LEF. The solenoid is only about

[Artie]

MINE MIGHT GO TO .85 BREIFLY UNDER CERTAIN CONDITIONS, BUT LOOKING AT THE GAUGE I THOUGHT IF IT GOES UP TO AND OVER 1.0 IT SHOULD PROBABLY SHOOT UP THERE AT TIMES.

I WILL PAY CLOSER ATTENTION TO IT, AND LET YOU KNOW.

WERE IS THIS SELONOID?

MINE SEEMS TO GO UP TO 80C, AND SHOOTS OVER ON OCCASION, SO I DONT THINK THIS IS THE PROBLEM

The solenoid is the first solenoid inside the boot relay panel. Also, try taking your caps lock off so it doesn't seem like you're yelling at us! I'll attach a picture.

Artie

[jpspeedy]

1990 SE, WHAT SHOULD BOOST PRESSURE BE READING?

MINE SEEMS LIKE IT NEVER GOES ABOVE .5, IS THIS CORRECT?

Had the same problem when I got mine, no boost above .5 I notice that the car was running cold. Changed the thermostat the temp went up to 82c and boost came on full, it now goes 1bar and a little more anytime I want it. After some research the engine management system will not let on have full boost until temp is 79c. Check your thermostat

[KENCO]

The solenoid is the first solenoid inside the boot relay panel. Also, try taking your caps lock off so it doesn't seem like you're yelling at us! I'll attach a picture.

Artie

how do you test this part?

[Artie]

how do you test this part?

Thanks! It may be worthwhile to check and see if all the hoses are attached correctly, check with JAE (ask for Jeff) and see how much a new one of these is. Also, see if your problem is related to low engine coolant temps. If the car isn't above 175F then boost will be restricted to .5 or so.

Artie

[KENCO]

Thanks! It may be worthwhile to check and see if all the hoses are attached correctly, check with JAE (ask for Jeff) and see how much a new one of these is. Also, see if your problem is related to low engine coolant temps. If the car isn't above 175F then boost will be restricted to .5 or so.

Artie

ok, this morning driving to work, temp ok, past 80c, noticed that boost seems to be getting to about maybe...... 7.5.....under extreme conditions.

I had just removed all the slack from my throttle cable the other day and it made an improvement on boost from what i was used to, now getting full throttle opening.

I will check hoses this weekend, thanks!

[Vulcan Grey]

ok, this morning driving to work, temp ok, past 80c, noticed that boost seems to be getting to about maybe...... 7.5.....under extreme conditions.

I had just removed all the slack from my throttle cable the other day and it made an improvement on boost from what i was used to, now getting full throttle opening.

I will check hoses this weekend, thanks!

Boost is also limited by hight MAT temps (manifold air temps, sensor on the chargecooler outlet elbow) . If your chargecooler pump ison't working and the temps are too high, the boost may spike but then be restricted.

The chargecooler box should be pretty cold immediately after a drive, not hot.

[KENCO]

OK, here is what I found.

Checking the diaphram that connects to the turbo via a rod. I do not know what this is called...I found a brass fitting with a adjustment valve, seems to be factory, is it? Anyway the valve was turned in to almost off, I turned it out 2-3 turns and I get tons o boost! Pegs the needle, so.... I guess I will turn it back in to get the vacuum to keep it at max 1.0 boost, but what I need to know is....

1. What is this fitting, is it stock?

2. What should the boost be at max?

3. Is there a saftey valve or something if boost goes to high?

Thanks for any info...........

[Vulcan Grey]

That is the wastegate capsule. If it is adjusted properly, then the ECU uses it to control and limit the boost pressure. If it is not adjusted properly, then the ECU has no control and you may build too much or too little boost.

If yours is adjusted properly, and you still have reduced boost, then the ECU is limiting bosst for a reason, and you'll need to find out why and fix it (some of the reasons above are a good start)

Here's how to adjust it.

Wastegate Capsule Replacement

To remove the capsule, pull off the pressure sensing hose, remove the circlip from the flap valve operating

arm to release the actuator rod, and release the two capsule fixing nuts.

After fitting the new capsule, it is necessary to set the actuator rod length to achieve the specified maximum

boost pressure of 0.65 bar (9.5 Ib/sq.in). For this purpose a hand pressure pump (e.g. seat lumbar support

bulb) and 0 - 0.7 bar (0 - 10 Ib/sq.in) pressure gauge are required:

Apply pressure to the capsule, and observe the pressure required to produce an actuator rod movement

of 0.40 mm (0.015 in).

Specification = 0.58 + 0.02 bar (8.6 rt 0.25 Ib/sq.in)

If the pressure is below specification, the actuator rod should be shortened, and if above specification,

lengthened.

CAUTION: Do not turn, twist or force the threaded actuator rod emerging from the capsule and affixed to the

diaphragm. Hold this rod stationary whilst slackening the locknut and screwing the extension piece on or off the

actuator rod as required.

When the correct specification has been achieved, fit the rod onto the flap valve arm with the circlip, and

connect the pressure sensing hose.

Edited May 19, 2007 by Vulcan Grey

[Paul C]

Of topic, but i must ask about the Avatar?

It looks Pantera GT5 but i'm guessing at the colour, is it wood/cammo/rust or what?

[KENCO]

Of topic, but i must ask about the Avatar?

It looks Pantera GT5 but i'm guessing at the colour, is it wood/cammo/rust or what?

Ha Ha......

I think its a car built out of old picnic tables.........kind of what my car looked like when I got it, when my car is brought back with TLC that I will give it, I will put up a nice pic of it, But for now due to the previous owner it is in its transitional stage.....She is getting a nice bath this afternoon when the sun goes down.....

That is the wastegate capsule. If it is adjusted properly, then the ECU uses it to control and limit the boost pressure. If it is not adjusted properly, then the ECU has no control and you may build too much or too little boost.

If yours is adjusted properly, and you still have reduced boost, then the ECU is limiting bosst for a reason, and you'll need to find out why and fix it (some of the reasons above are a good start)

Here's how to adjust it.

I read about the wastegate capsule on LEW. But what my question is what is this brass inline fitting to it, is it an add on? Is it to adjust pressure due to other improperly adjusted parts from PO?

Thanks

[Vulcan Grey]

Ha Ha......

I think its a car built out of old picnic tables.........kind of what my car looked like when I got it, when my car is brought back with TLC that I will give it, I will put up a nice pic of it, But for now due to the previous owner it is in its transitional stage.....She is getting a nice bath this afternoon when the sun goes down.....

I read about the wastegate capsule on LEW. But what my question is what is this brass inline fitting to it, is it an add on? Is it to adjust pressure due to other improperly adjusted parts from PO?

Thanks

Oops I missed the part about the adjustment valve on the wastegate.

That's a bleed, its basically a manual boost controller, it basically takes away some of the control of the ECU over the wastegate, so that it won't open when it normally would.

That could also cause you to have too much, or too little boost. In order to diagnose your boost problem, you would need to close that so the ECU is fully able to control the wastegate, only then can you see if everything is working correctly.

[KENCO]

Oops I missed the part about the adjustment valve on the wastegate.

That's a bleed, its basically a manual boost controller, it basically takes away some of the control of the ECU over the wastegate, so that it won't open when it normally would.

That could also cause you to have too much, or too little boost. In order to diagnose your boost problem, you would need to close that so the ECU is fully able to control the wastegate, only then can you see if everything is working correctly.

Well that bleed valve.............I have it adjusted so I get good boost now.

But I still need to know, what is the boost I should be running, with this valve I can adjust it to do whatever I want, tons of boost is no good correct?

What is a safe maximum boost level?

[98GT3]

Well that bleed valve.............I have it adjusted so I get good boost now.

But I still need to know, what is the boost I should be running, with this valve I can adjust it to do whatever I want, tons of boost is no good correct?

What is a safe maximum boost level?

I may be wrong, but an adjustable bleed valve in the line sounds like an aftermarket piece to me. They sell them to bleed off some of the pressure to fool the ECU on how much boost it has and therefore supply over what was intended by the manufacturers. As I say I may be wrong, but I think this piece has no place in an Esprit and could cause permanent damage. If the car is running properly the boost should look after itself, and should you want more power there are much better ways of increasing boost safely - namely a chip upgrade. Have you done a freescan log of your engine? this is probably the best way to diagnose any fault you have that is limiting boost - but for now I would make sure that valve is well and truly shut!

Phil

98GT3

[pitstoppete]

A freescan log with wastegate solenoid electrical connector disconnected, and with any sort of bleed valve gismo thrown away, then u may see what it gives with just the mech. bit of the wastegate working. should be adjusted to give 0.65 bar, IIRC. then plug the plug back on. then should go to 0.85, then 1.0 bar, if, as travis says, all is ok with MAT and the CC.

also, freescan to check the actual coolant temp the ECU sees via the CTS, ignoring the dash gauge really, as they lie for a living. mine shows 60 when its actually 82.

[KENCO]

I may be wrong, but an adjustable bleed valve in the line sounds like an aftermarket piece to me. They sell them to bleed off some of the pressure to fool the ECU on how much boost it has and therefore supply over what was intended by the manufacturers. As I say I may be wrong, but I think this piece has no place in an Esprit and could cause permanent damage. If the car is running properly the boost should look after itself, and should you want more power there are much better ways of increasing boost safely - namely a chip upgrade. Have you done a freescan log of your engine? this is probably the best way to diagnose any fault you have that is limiting boost - but for now I would make sure that valve is well and truly shut!

Phil

98GT3

I dont believe it is a bleed valve, more of a restrictor valve, to adjust the amount of vacuum that is going to the turbo diaphram. Fully adjustable and if adjusted correctly why would this hurt anything?

Also I get correct boost when the engine is cold, below 80C.

Do you think I need to reset the computer to adjust to everything?

Edited May 23, 2007 by KENCO

[98GT3]

I dont believe it is a bleed valve, more of a restrictor valve, to adjust the amount of vacuum that is going to the turbo diaphram. Fully adjustable and if adjusted correctly why would this hurt anything?

Also I get correct boost when the engine is cold, below 80C.

Do you think I need to reset the computer to adjust to everything?

Do you think you could post up a picture of this part so we can all see what you are talking about. The big problem with any form of bleed or restrictor type valve is that they do not control pressures to set values and are highly dependant on the the pressures they see.

Phil

98GT3

[KENCO]

Do you think you could post up a picture of this part so we can all see what you are talking about. The big problem with any form of bleed or restrictor type valve is that they do not control pressures to set values and are highly dependant on the the pressures they see.

Phil

98GT3

Will get a pic up...........

[KENCO]

OK, found out what it is.......... its a boost controller, seems to work as stated on the internet.........I like it!

Actually did a rolling burnout by accident this morning...........heh... heh..............

[98GT3]

OK, found out what it is.......... its a boost controller, seems to work as stated on the internet.........I like it!

Actually did a rolling burnout by accident this morning...........heh... heh..............

Does it have any wires going to it..................probably not................not really a controller - more like a boost confuser if it's what I think it is! You may like the results at the moment, but you could pop your engine......you have been warned!!!!!!

Phil

98GT3

[KENCO]

Is there not a boost safety valve? If boost goes to high it cuts out?

So what is normal boost pressure?

[Artie]

Is there not a boost safety valve? If boost goes to high it cuts out?

So what is normal boost pressure?

The ecm will limit boost regardless of boost set pressure via controller. However, if boost goes too high and lots of pinking occurs damage can already be done! Normal boost on an SE is .85bar.

Artie