Check & Adjust IP internal Pressure

[2strokesmoke]

Hey Guys,
I want to check & adjust IP internal pressure,on my 1985  1.6TD
This is something I haven't done before - but seems quite simple,from the info I have found.
Is there a thread detailing this procedure and what the pressure specs are ?
I have only found bits and pieces of info.
I have a 150 PSI pressure gauge & I made a fitting from an old IP OUT Banjo bolt (with small hole)
Also- Does ambient temp or engine temp effect the pressure setting/adjustment ?
Thanks,Mike

[ORCoaster]

Sounds like you are set up to do this.  I question the "a fitting from an old IP OUT Banjo bolt (with small Hole)"  Is this intended to be placed where the current OUT banjo is now? 

Will it be stacked on top the current OUT Banjo and a longer bolt used?  Does the small hole mean as the original set up is put together?  That will not give you the IP pressure as the small hole regulates the pressure.

There are threads on here that demo the different ways you can monitor the internal pressure.  Idle is 43 lbs and full on it at shift points is 74 lbs.  That is where the pressure is moving the advance to the maximum. 

Do you know how to change the pressure by tapping the regulator down a very small bit at a time with a punch and hammer?  Do you know what to do if you exceed the 43 lbs at idle? 

Continue your search.  I know that we all discussed this long and hard between us.  Pictures in some of the posts as well.  Best method goes to Libby for tapping a hole in the side of the pump and taking off the measurement that way.  It was the cleanest and best means by far.  I ended up with a double banjo setup and had lots of leaks until I put new copper washers to use. 

[2strokesmoke]

Hi,
Thanks for your reply
The fitting I fabricated was:
I used an IP OUT Bolt (fuel return bolt for banjo,which has OEM Bosch orifice) from a spare IP
On TOP of the bolt, I drilled and tapped a hole,screwed in a fitting which allows connection of my snapon fuel pressure gauge
If my thinking is correct,this should measure fuel pressure BEFORE it exits orifice
I'll take a pic of fitting I made up and try to post it.
I did see a post about using a punch & hammer to increase pressure and also how to reduce pressure.
Thankyou for the fuel specs -that was what I was looking for.
Does engine temp,fuel temp,effect this pressure ?
should I adjust with engine at operating temp ? Or maybe it doesn't matter ?
Thanks,Mike

[2strokesmoke]

Here is the fitting I made up :





I removed the internal screen,to make sure no metal shavings got trapped in the bolt-which may clog the orifice.
Will this setup measure IP pressure correctly ?
Thanks,Mike

[ORCoaster]

I don't think fuel temp or engine temp make much of a difference here.  Maybe a tad of a few lbs maybe if it was in the 20's F or something but otherwise not likely.  I don't see much of a difference in my pressure when cold or hot.  It cycles back to the fuel tank so it stays pretty much the same all the time.

I adjust at engine operating temps just so that I know that once the engine is warm it is going to be at those settings.  Kind of like most settings, set for what the conditions will be when operational.


Just saw the fitting.  Looks great and yes it will do the job. 

Your welcome, DAS

[2strokesmoke]

Awsome
I'll be trying it tomorrow
Thanks for your help !
Mike

[745 turbogreasel]

Test bench runs calibration fluid at 40C, but in the real world, probably not much difference.

[TylerDurden]

Some references show IP internal pressure ranges from ~40psi to ~110psi.

70psi seems a bit low for the upper end.

Of course, it depends on IP regulator spring value... similarly, the timing rely on the timing spring and shims.

[libbydiesel]

That fitting should work, but I'm not a fan of doing it that way.  The OUT bolt is part of the equation and swapping it out for the test fitting means that you aren't testing the pump pressure with the actual OUT bolt you will be using when running the engine.  I like mine better as it threads into the pump and the actual OUT bolt that will stay with the pump threads into it.

 

There is still some potential for a slight difference in pressure due to a difference in thread tightness, but that is present in either case.

[ORCoaster]

Tyler,  Interesting on the top end pressure.  I cruise with at steady 75# at 65 mph.  But if I need to pass a slower moving car and down shift I can get my IP gauge to register the 100 mark.  Smoke is generally belching out the back and I am sure they are cursing me big time but they were going 64.5.

I thought I had the regulator tapped down farther than it should be at idle and that is why I was seeing the extended top end.  I do have a weaker spring in the pump.  It isn't the famous green but the next in line the silver colored one.  I pulled the red one out of it and a shim to boot.  Maybe that is the cause of the smoke, to much advance.  Might drop a shim back in and see what happens. 

Thanks for the numbers.  I was going off what I gathered from Hagar when he was posting back when. 

Later DAS

[ORCoaster]

I used a proper threaded bolt that I drilled out and then soldered a nut on top of that.  I used a spare IN Banjo for the take off hose.  The original OUT bolt and the out Banjo fit on the top of that. 


Gets me a reading as near to the pump that I could think of at the time.  Not quite as clean as Libbys extension with the tapped in fitting. 

[2strokesmoke]

Hey guys,
Well I checked my IP pressure @ 1000 RPM which was at 28PSI 
Before adjusting, I checked at 2000RPM as well (also very low)
While holding RPM @ 2000 for over 30 seconds- I think my true problem showed
Air Bubbles in the clear line to IP !
No bubbles at idle,but after 30 seconds at 2K, the bubbles started flowing-and got worse the longer I held the RPM
This really pisses me off !
A year ago, I installed a NEW fuel tank,new one piece steel feed line and new one piece return line-
From tank to firewall- no fittings or splices-all one piece- to avoid this from happening.
I had also installed a new OEM lift pump,in the tank.
It is a free flowing pump (meaning- with pump OFF- fuel flows freely thru it)
At the time,I had read many posts about using a lift pump
Some people swore it was a good idea,some people swore it was a bad idea
I figured-sence it was a free flowing pump, I could easily disable it by removing the pump relay (this is in a Fox 1.6TD conversion)
So- I have been running with pump off
Guess what- I put the pump relay back in
with pump ON,no more air bubble at all (and no leaks) and IP pressure increased to 35PSI
So I adjusted pump pressure to 43 PSI @ 1000RPM with pump ON
Now have very little fuel smoke at idle,don't see any smoke behind me while driving,turbo seems to spool a little sooner,engine sounds better-power is still about the same though (may be partly due to gearing (2500RPM @ 65MPH)
I will run it this way for a while,to make sure smoke is gone,than maybe I can turn fuel up a bit,to help power

[2strokesmoke]

Hopefully those darn air bubbles are gone for good.
I had a Full tank of fuel,when I checked IP pressure
So I wouldn't think I would be sucking air,from inside the tank-
I checked hose connections at tank,at fuel filter,ect- all good,all tight,all dry.
I'm begining to wonder- maybe when I checked the lift pump(before install)in was in just the right position-so it would free flow easily
then once I installed it and tested it, the pump internals were now in a different position,so it wouldn't free flow as easily ?(causing a restriction)
The only thing I can think of.
I guess time will tell

[ORCoaster]

Glad you got it tuned, some unexpected diagnostics there to boot.  Run it for a while and see how your mileage comes out on a couple of tanks.  My guess is it will improve.  Remember power (aka black smoke) comes out the tail at the expense of mileage.  Odd about the pump but not expected.

Where did you obtain the pump?  Cost and GPM rating?

Nice addition and you see how just a bit of extra coming in the front of the pump changes everything. 

Let us know how it runs after a bit. 

[2strokesmoke]

I purchased the in tank lift pump,from autohouseaz.
It is the stock lift pump,which feeds the external high pressure pump-(this car is a 88 fox-originally had a gas fuel injection system)
I think the pump was rated at 3-5 PSI from my research
As far a fuel milage- I was actually getting 53MPG all highway (probably due to the gearing of the 5M trans-2500RPM @ 65MPH)
But around town-local driving -fuel milage went WAY down.(thats when the car was smokey)
I was actually going real easy on the pedal-just so I wouldn't get a ticket !(the smoke was bad if you drove it hard)
over 6lbs of boost,the smoke went away/diminished (which is probably why the highway milage was good)
I wouldn't mind giving up some MPG's,to get a little more power,because this car is underpowered,due to the gearing I think.
In comparision-My 82 Caddy (which I sold 2 months ago) with 1.6NA, got 45 MPG with no smoke and had a LOT more power than the fox
And the fox is a lighter vehicle.
So- I'll drive it for a week.
If still no fuel smoke- than I can turn up the fuel a little bit.
Thankyou all for your help !
Mike