Tuning Correct boost pressure(s) for 1.9JTD

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Tuning Correct boost pressure(s) for 1.9JTD

Sinny

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Just fitted a boost gauge to the Schlampe and it's starting to boost a tiny bit, maybe a .1 of a bar around 2000 rpm - after initially "sucking back" a little bit - going just into vacuum - then gradually getting up to full boost at 4000 rpm - max is about 1.4 bar. There's no boost whatsoever under 2000 rpm. :confused:

Can anyone point me to some official figures for what boost should be at certain revs please?

Has anyone else fitted a boost gauge? I've taken pics of the work involved and will do a bit of a write up over the next week or so if anyones thinking about it ;)
 
Is it an easy job?hiw long did it take you. Is your dobli chipped?

About an hour and a half, including cleaning the throttle body. You could blank the EGR all in the same job the way I did it.

Easy? Mechanic: eyes closed, one hand behind back.

Sunday morning hobbyist: 2 spanners out of 5.

I may as well do a bit of a write up:

Before you start, buy a brake bleed nipple - ideally one about 30mm long, and a rubber tap washer (the old fashioned type with a hole through) and a nut that the bleed nipple screws into - I believe this is about 7mm but I found the one I needed in a box of wonders and I have no idea what it is :) You will also need either silicon mastic or perhaps better, a 2-pack glue. I leave that judgement to you. I used mastic. Technically, the pipe (now my EGR is blanked shouldn't get anything in it that will attack the mastic. If something does, I suspect the mastic coming unstuck will be the least of my worries :D

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Steps:

1) Take the top cover off the engine. 10mm socket

2) Take out the battery and the battery box. (10mm and 13mm socket + extentions)

3) Undo until very loose the jubilee band round the "in" pipe from the inter-cooler to the throttle body. DO NOT pull the inter cooler pipe off the bottom yet, because if you drop something, Sods Law dictates that it will end up in it ;) (9mm socket)

4) Loosen the 3 bolts holding the throttle body to the end of the inlet manifold. (13mm socket and extension)

5) take out the 2 Allen headed bolts holding the corrugated pipe to the EGR - LONG Allen key or star key 8 or 9mm (can't remember!) (You could move the fuel filter but you just have to push it out of the way half an inch for the allen key, so I didn't bother.

6) Use a small screwdriver to tease the vacuum pipe from the throttle actuator.

7) Undo the nut holding the pipework captive fitting to the top of the throttle body, pull the pipework clear.

8) Fully undo and remove the 3 13mm bolts that hold the throttle body and inlet manifold together. Keep an eye out ready to catch the gasket from between the throttle body and the inlet manifold if it falls. The whole throttle body assemble can now be worked out of the inter cooler pipe and pulled out.

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9) Clean the whole thing thoroughly with whatever your favourite cleaning agent is and dry it.

10) While the throttle body is drying, carefully work a drill into the hole in the end of the bleed nipple - drill it right through, open it up as much as possible. You want free flow through it, and as bought, it wont be. When you're happy with it, put it to one side and get your nice clean dry throttle body.

11) Drill a pilot hole in the throttle body around 30 - 40 mm before the flange that joins it to the inlet manifold, and around the 2 o'clock position when the body is mounted to the inlet manifold.
Use the hole for the 13mm bolt as a guide for this - you want to be able to get your socket and extension back on without the bleed nipple being in the way.
open the hole out so that the hole is an interference fit on the nipple's screwed end - because the body is ali and the screw is steel, it will cut a bit of a thread for itself - but you MUST get this right. Remember: you can take away, but you can't put back ;) the nipple has only a tiny land - it's only slightly wider than it's thread... and theres nothing worse than a hole thats a bit too big.. ;)
Once you have the nipple sitting right, and the hole is a nice interference fit, stick your fingers up the throttle body and pur pressure on the nipple with your thumb and using a spanner turn the nipple into the hole. As it cuts it's thread you'l feel it "bite" and once it's done a couple of turns nip it right up against the throttle body.
Inside the throttle body put mastic or epoxy caefully around the thread of the nipple (you don't want to block it) then work the rubber washer down the thread of the nipple and then screw the nut on tight. Add mastic / epoxy until you're happy it's not ever going anywhere, and set aside to dry.

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12) "refitting is the reverse of removal" as they say. If you're blanking the EGR, then stick your blanking plate in and you're done.

I think it is probably easier to do as I did and mount the pipe for the gauge *before* putting the throttle body back on the car, but that's a matter of choice.

Battery back on, fire it up, and you should be good to go...

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Sadly, bad light stopped play... If the weathers nice tomorrow, the gauge goes in the car. For now it's in a plastic bag tied up out of the way in the bonnet.
 
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nice write up and always nice to get pictures.

Did you blank the EGR on the engine side of the valve then? I have mine to do next week, Im also putting a new EGR valve in (mines buggered and i managed to pick up a genuine Pierberg one cheap on the bay) so ill blank it on the exhaust side. Im putting the plate in with the 10mm hole in it so the valve will still open and close and i shouldnt get a cel.

There is no way mine has any boost at anywhere near 4000rpm! Do you think a stuck open egr valve would cause that!?

otherwise i suppose its checking to see if the wastegate arm moves freely and then after that checking for pressure leaks. :mad:
 
nice write up and always nice to get pictures.

Did you blank the EGR on the engine side of the valve then? I have mine to do next week, Im also putting a new EGR valve in (mines buggered and i managed to pick up a genuine Pierberg one cheap on the bay) so ill blank it on the exhaust side. Im putting the plate in with the 10mm hole in it so the valve will still open and close and i shouldnt get a cel.

There is no way mine has any boost at anywhere near 4000rpm! Do you think a stuck open egr valve would cause that!?

otherwise i suppose its checking to see if the wastegate arm moves freely and then after that checking for pressure leaks. :mad:

I blanked my EGR previously, at the other end of the corrugated pipe, close to the throttle body.
I don't think a stuck EGR would affect boost? far as I'm aware, it's only there to chuck cr*p into the inlet manifold when the conditions are right. :rolleyes:
Mine being the older less sophisticated kind doesn't get a light come on even though it's completely blocked - and it did make the whole thing drive a bit nicer.

To be honest I'm going to wait until the turbo boost adjuster turns up then fit that and see what happens. The waste-gate operation seemed free enough when I was under there a couple of weeks ago.
There has always been a noticeable gain in performance - a proper "kick in the arse" - as it hit the 2000 + rpm mark, and now I realise why - there's virtually sod all boost before that point :confused:

I'm Googling and finding figures like 2bar boost, and I'm getting nowhere near that, although I've not found anything definitive yet, just people saying what they are getting on forums.

Not sure where to look, really, but I cant believe there aren't some standard boost figures at given revs out there somewhere. :confused:
 
my thinking with the EGR is that if its stuck open, the pressure in the inlet manifold will be less?

On my van there is no shove like you describe at 2000rpm and it has now started whistling. (although im still not sure if thats not the roof rack! :D).

My 9-5 has 300bhp and that doesnt feel too quick anymore, so maybe my 'arse dyno' is out of sync for a 105bhp van! :cool:
 
Hey ive got boost gauges in my scudo.... Think its just the vac that works on mine if that makes sense.. A friend fit mine and water temp loooks the part tho ?


You need to get your friend back round - a Diesel doesn't have vacuum :D thats why I was a bit confused with mine, because when you first put your foot down theres a definite move towards the vacuum end of the scale - not much, but a bit.
 
my thinking with the EGR is that if its stuck open, the pressure in the inlet manifold will be less?

On my van there is no shove like you describe at 2000rpm and it has now started whistling. (although im still not sure if thats not the roof rack! :D).

My 9-5 has 300bhp and that doesnt feel too quick anymore, so maybe my 'arse dyno' is out of sync for a 105bhp van! :cool:


I'm really not sure on the EGR valve affecting the Turbo. In the normal run of things, the pressure into the inlet from the EGR must be enough to overcome the boost from the turbo? Or the boost would end up in the sump when the EGR opened to chuck **** into the inlet? :chin:

If you've got a whistle, that will almost certainly be why you're losing boost. You must have a leak in the pipework somewhere... unless it is the roofrack :D

It must feel like a slug after 300BPH :p
 
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I'm really not sure on the EGR valve affecting the Turbo. In the normal run of things, the pressure into the inlet from the EGR must be enough to overcome the boost from the turbo? Or the boost would end up in the sump when the EGR opened to chuck **** into the inlet? :chin:

yes, thats a good point.

I found this online which explains a bit about the EGR regarding its effects on engine performance...

"EGR is considered a `metered intake leak' and was developed to reduce the combustion temperatures to below 2,500 degrees, the threshold where NOx is created. Not unlike putting a brick in your lavatory to lower the volume of water used, the EGR valve meters a readily available inert gas (actually exhaust gas which contains a lot of very inert Carbon Dioxide) into the combustion chamber to effectively reduce the volume. Smaller effective displacement means less fire, and less heat and thus lower temperatures, thereby controlling NOx emissions.

Obviously we don't want to `reduce' the volume of the combustion chambers (effectively reduced engine displacement) during hard acceleration, so EGR is turned off when you need full power (WOT (Wide Open throttle) conditions)"
 
yes, thats a good point.

I found this online which explains a bit about the EGR regarding its effects on engine performance...

"EGR is considered a `metered intake leak' and was developed to reduce the combustion temperatures to below 2,500 degrees, the threshold where NOx is created. Not unlike putting a brick in your lavatory to lower the volume of water used, the EGR valve meters a readily available inert gas (actually exhaust gas which contains a lot of very inert Carbon Dioxide) into the combustion chamber to effectively reduce the volume. Smaller effective displacement means less fire, and less heat and thus lower temperatures, thereby controlling NOx emissions.

Obviously we don't want to `reduce' the volume of the combustion chambers (effectively reduced engine displacement) during hard acceleration, so EGR is turned off when you need full power (WOT (Wide Open throttle) conditions)"


having read that, a) no wonder it felt better with it blanked and b) I'm 8l00dy glad I could blank it :D

I've found some truths - as opposed to wild conjecture and willy waggling on Alfa forums :p - and it seems that max boost *should be* around 1.4 bar - but 1.5 is OK, 1.6 seems to be OK as well, but much more than that and you're asking for trouble unless it's part of a remap.

Also I'm reading that no boost under 2k rpm is normal?? :confused:
 
yes, thats a good point.

I found this online which explains a bit about the EGR regarding its effects on engine performance...

"EGR is considered a `metered intake leak' and was developed to reduce the combustion temperatures to below 2,500 degrees, the threshold where NOx is created. Not unlike putting a brick in your lavatory to lower the volume of water used, the EGR valve meters a readily available inert gas (actually exhaust gas which contains a lot of very inert Carbon Dioxide) into the combustion chamber to effectively reduce the volume. Smaller effective displacement means less fire, and less heat and thus lower temperatures, thereby controlling NOx emissions.

Obviously we don't want to `reduce' the volume of the combustion chambers (effectively reduced engine displacement) during hard acceleration, so EGR is turned off when you need full power (WOT (Wide Open throttle) conditions)"


This might give you some ideas?

http://www.alfaowner.com/Forum/alfa-147-156-andamp-gt/232563-jtd-jtdm-mcsf-andamp-other-problems-fix.html

They are saying the EGR will affect power below 2K - although I still cant for the life of me understand how... :confused:
 
yes, thats a good point.

I found this online which explains a bit about the EGR regarding its effects on engine performance...

"EGR is considered a `metered intake leak' and was developed to reduce the combustion temperatures to below 2,500 degrees, the threshold where NOx is created. Not unlike putting a brick in your lavatory to lower the volume of water used, the EGR valve meters a readily available inert gas (actually exhaust gas which contains a lot of very inert Carbon Dioxide) into the combustion chamber to effectively reduce the volume. Smaller effective displacement means less fire, and less heat and thus lower temperatures, thereby controlling NOx emissions.

Obviously we don't want to `reduce' the volume of the combustion chambers (effectively reduced engine displacement) during hard acceleration, so EGR is turned off when you need full power (WOT (Wide Open throttle) conditions)"


Now look what I just found... :D

Guess what I'm about to do... ;)

https://www.fiatforum.com/croma-ii/246118-clean-your-boost-sensor-now.html
 
Well I'm of the opinion that I have a gauge that reads exactly half what it should. The van goes like the clappers and will chirp the wheels in 2nd on a damp road and yet it does all that on about .7 bar.

I aint buying it...

I've now cleaned every flippin sensor, valve, MAF, MAP, EGR, been right round it for leaks with soapy water, checked it holds vacuum, the works...

And heres what I get :D

https://www.facebook.com/sinbad.glen/videos/10153846367663360/
 
Boost control solenoid?

Its a small block (or cylinder) with 3 small bore vacuum lines attached to it.

I believe they are susceptible to water damage/ingress, they certainly are on the punto/stilo, where owners tend to move it onto the side of the battery box to help 'shield' it more effectively.
 
Boost control solenoid?

Its a small block (or cylinder) with 3 small bore vacuum lines attached to it.

I believe they are susceptible to water damage/ingress, they certainly are on the punto/stilo, where owners tend to move it onto the side of the battery box to help 'shield' it more effectively.


Ah, down on the block, right hand side as you stand at the front?

I couldn't get the plug off it. maybe I'll have a look at that tomorrow.

I have to say, it goes like stink even if it's not producing the right boost :confused:
 
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