Welcome back to another edition of "This Old Diesel"


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The 29/64 " die I used yesterday on the probe worked again today.


http://www.dieselplace.com/forum/uploads/86F_boost2.jpg


Aluminum is as soft as butter. it took 15 min. to disassemble tap/thread the hole and clean it w/ carb cleaner and reinstall with bushings PTFE taped inplace.


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I ran the nylon tube in the pyro probes wireloom, it goes to the same place. My guages are just sitting on my dash. Tomarrow I'll work on a guage pod.











Edited by: quantum mechanic

Now I can't wait to do this on my truck! Be sure to include pictures of the finished install.

When I do it I'm thinking pyro, boost, and tranny temp. Don't want to blow up the 4L80-E prematurely. Even though it only has 172k on it I'm pretty hard on it with all the heavy towing I do (car trailers w/cars attached).

QM I was looking at your pics nice job by the way but was wondering if you can install the boost gage in the neck of the Air Intake I already have a hole tapped there and was going to install it there my question will it work there?





Rick

Anywhere after the turbo and before the runners of the lower intake will work. Still to come are exhaust backpressure and tranny temp. guages/probes.

i mounted my boost/egt gauges in my tahoe in the overhead console. if you have an overhead console and no rear controls for an Aux AC, this is a good place, with a little work they look factory, no one believes i did the install with just a holesaw and some sandpaper. I have banks gauges and they match the stock dash gauges quite well

I mounted my boost gage under the dash between the steering wheel and the door, down near the ODBI plug. Now I got a stupid annoying very slow yet horribly messy oil drip coming from the gage.


I was told it was normal for 6.5's to get oil from the crank case into the intake somehow.


I think if I mounted the gage higher some place the oil would drain back into the intake and no more drip. But I don't want to chance it and end up with an oil drip on my dash, seats, or carpet, depending on where I'd mount it.


Good thing I got those heavy duty rubber floor mats.Edited by: w_huisman

I ran my wires/tube to the apilar. I never thought of the overhead.


http://www.dieselplace.com/forum/uploads/D4E_boost.jpg


Here's one more, remember that this is a 94 HD but it came with a castweb and center colum for an EGR tap I don't have. I have an hour or two into cleaning it up. Can you tell? It would have been easier to get a non EGR boss like the 96+ has.


Do you think the bushing is sticking too far inside or would it matter?Edited by: quantum mechanic

I don't think it matters.

I mounted my boost gage under the dash between the steering wheel and the door, down near the ODBI plug. Now I got a stupid annoying very slow yet horribly messy oil drip coming from the gage.


I was told it was normal for 6.5's to get oil from the crank case into the intake somehow.


I think if I mounted the gage higher some place the oil would drain back into the intake and no more drip. But I don't want to chance it and end up with an oil drip on my dash, seats, or carpet, depending on where I'd mount it.


Good thing I got those heavy duty rubber floor mats.





If oil is leaking out of it then air is too. With it sealed good, the oil wouldn't go that far up the tube.

When fitting is overtightened with nylon tubing, result is a leak.


Get another 1/8" fitting set from local auto parts, cut nylon tubing off at 1/4" before old ferrule, re-install with new ferrule and nut.


QM depth of fitting into plenum is not important, long as it doesn't leak

If oil is leaking out of it then air is too. With it sealed good, the oil wouldn't go that far up the tube.


You know, I had that thought myself once too, but it was one of those "in one ear and out the other" kinda things.


When fitting is overtightened with nylon tubing, result is a leak.


Get another 1/8" fitting set from local auto parts, cut nylon tubing off at 1/4" before old ferrule, re-install with new ferrule and nut.


Good idea. But I had a quick connector type of ferrule/nut thingy that you just slide the tubing into and it gripped the tubing as you tighened the ferrule/nut fitting on the back of the gage. I don't think they'll have that fitting at the hardware store. But I spose they'll have the normal type ones that I can make work. I know I have plenty of extra tubing rolled up under the dash, so I can make many mistakes before I run short of tubing.http://www.dieselplace.com/forum/smileys/Big Smile.gif


Thanks guys. http://www.dieselplace.com/forum/smileys/Hug.gif I had just began to believe that the oil drip was going to be a fact of life and didn't give it much thought. Hopefully I can get that darn thing sealed up and end the oily mess on my floor mat once and for all.

That should be a standard 1\8" ferrule\nut fitting on the gage - available at any good auto parts house for all the oil pressure\etc gages.

Good pic QM of a non EGR tap, on EGR upper I went here, 1st pic is my original location in the snorkle, 2nd pic is current location, I relocated to there to see if there was any differences from pitot tube effect of fitting in air stream as snorkle is thinner than upper housing, slight differenct boost in 1st location reacted a litte faster than current location, bottom line either work, more meat is available for tapping in 2nd location.


http://www.dieselplace.com/forum/uploads/687_DCP00579.JPG


http://www.dieselplace.com/forum/uploads/266_tdtap.jpg


Changed the contrsat on kennedy's and your picture for a better look.Edited by: quantum mechanic

I took it out for a drive. It appears that I have 0 boost at idle and don't see the needle move much 'till 2000 rpm. I've checked the wg vac system with the same guage. It read 15" after and 21.5" before. On a hard acceleration it spiked to 8 psi but mostly ran at 5 psi. I feel I must have a manifold leak somewhere. the pyrometer read between 450-600 deg F depending on how much pedal I had into it. I spiked it to 900 deg on one hill but as soon as I let the fuel off it settled toward the low end.


What really counts is what it looks like next time I haul a load.

spiked at 8psi and ran at 5??? I thought that map sensor resistor mod you did gave you more boost than that, mine, stock will spike up to 12 and ride at 7-9.

As I said, I'm looking for the manifold leak. I might not have put the lower on right the last time or something. I have wg function, just not full boost. had to have a guage to notice it and then drive me nuts till I figure it out.

If you had a leak, the computer, sensing the low boost, which it would see as even lower with the resistor inplace, would compensate by raising the WG solenoid duty cycle, so you should make the same boost provided the leak is not so bad that the turbo can't keep up, if it were that big, you would hear it.

Those will be your normal readings unloaded.


Check Wastegate Duty Cycle % to see how PCM manages it.


Boost is made by exhaust energy - heat and volume.


Heat (EGT) is load, volume is rpm.


Low rpm, hi load - more fuel creates more heat creates expanded volume = more Boost.


Check with your scanner to see what Fuel Rate corresponds to Boost level at different rpm and loads, compared to EGT.


Levels start dropping, check Intake Air Temp and Fuel Rate to WG Duty Cycle.


Some scanners allow selecting five or so parameters to keep on top - IAT, FUEL, WG DC, Boost are primo readings for R&D observation, on top of Engine Coolant Temp, Desired\Actual Timing, RPM, and FS Closure Time.


Verify mech Boost gage to scanner readings, so you'll feel comfortable in relying on it.

Did you use NPT pipe thread for the fitting? If not that could be your leak source.

Did you use NPT pipe thread for the fitting? If not that could be your leak source.


I used what came with the gage kit from Heath.


I climbed under the dash and noticed that the drip wasn't coming from the ferrule or the ferrule nut. It was coming from the threads where the adapter (the part that the smaller ferrule nut threads to on one side, and on the other side threads onto the gage housing) fitting threads onto the gage.


I tightened that thing up, so hopefully that'll take care of the drip. If not, then I'll probably try a little thread sealer.Edited by: w_huisman

I've always preferred to drill it into the round part of the manifold cover. It's thickest here, and drilling so the tubing runs horizintal minimizes the strain.





http://www.dieselplace.com/forum/uploads/EBZ_kennedytap.jpg Edited by: quantum mechanic

Nice job cleaning up the lip on that intake. Can you take it off and show us any other cleanup you do?

Dave

i picked up about 3 psi when i replaced my crossover doughnut gasket on the passenger side. then had to back off my turbomaster to keep from kicking into limp

I found an exhaust stain next to my pyro tap. I'll try sealing that up first. Do you guys think liquid steel will work?

I've always preferred to drill it into the round part of the manifold cover. It's thickest here, and drilling so the tubing runs horizintal minimizes the strain.





http://www.dieselplace.com/forum/uploads/EBZ_kennedytap.jpg





Same place I drilled mine 1st time but opposite side, word of caution, don't run tap in too far as the fitting will not draw up properly against the pipe thread taper, and a small amount of fitting can extend into the air stream. I went too far with mine, and thought it was causing me to have an indicated boost drift problem 1-2 psi rapid needle on hard accel above 7 psi, still have same indication with relocated position.

I found an exhaust stain next to my pyro tap. I'll try sealing that up first. Do you guys think liquid steel will work?


If it's cosmetic problem I wouldn't worry with it; hey you are relieving backpressure http://www.dieselplace.com/forum/smileys/HiHi.gif,


regular liquid steel probably won't work too high a op temp, I do have a gas BBQ grill with a JB weld repaired lid that has held up 5 years, use the std cure time stuff,not quick cure which does not seem to hold up as well IMO.

I sealed the bushing but saw a new exhaust stain just smaller than before.


My timing is running at 8.5 des/9.5 actual. The tool reads 15.4 psig (1.43v) at idle on 10.01K ohms fixed resistors, boost guage sits at the low side of 0.


At 17.4 psig the boost guage is at the high side of 0.


At 22 psig it shows 5 psi.


I've had the crossover on and off a few times recently. I'll have to look for soot stains around the collectors. I think I should be making more boost than this.

QM,


At 22 psig it shows 5 psi.


(where are you getting this reading) from scanner


(are you converting kPa to get 22psia), PCM output reading is psia (- 14.7 for equivalent gage reading) should be 7.3 or so psig assuming kPa to psia conversion is correct.


Also is that reading with boost fooler installed?

You could always go with a larger bushing.

When I turn up the pot. switch it just drops the volts .23 in addition to the fixed resistor that is also there and reading to 19.7 psig peak but the boost guage brarely will spike above the 5 psi on a mild acceleration. I've seen psig of 30 in the past, so leaking exhaust/intake would make sence. Still havn't looked at the crossover.Edited by: quantum mechanic

With the resistors, it reads higher boost on your scanner?


What does it read with the engine not running? It should be a negative number with the resistors and 0 without.

QM,


At 22 psig it shows 5 psi.


(where are you getting this reading) from scanner


(are you converting kPa to get 22psia), PCM output reading is psia (- 14.7 for equivalent gage reading) should be 7.3 or so psig assuming kPa to psia conversion is correct.


Also is that reading with boost fooler installed?





My scanner reads in PSI and follows my gauge exactly all the way up to the top of the gauge.

With resistors it reads lower. That means 22 psig + the resisted value.


now that I have the guages, I'm ready to find out what's working or not and where's the limit.


I saw soot around the collector/turboexhaust manifold flange, Loosened moved the flange and retightened the bolts. then I put more liquid steel around the pyro bushing. Next I bent up a piece of aluminum sheet into a guage housing.


http://www.dieselplace.com/forum/uploads/F1E_guages.jpg


Retarded the pump 1 mm maybe 7.5-8.0 actual timing didn't scan.I went for another test run, This time I saw 6+ psi on the new boost guage pot. switch off. 8 psi with it full on.


The only place I saw oil on the intake is around the bolt side of the inlet and I'll try resealing that tomarrow.Edited by: quantum mechanic

If I were you, I would try the map sensor off the '96 truck and see what the readings are. It should only take a minute to swap them.

Update:


Today, I sodered in two more 10K ohm fixed resistors on the MAP and one 5.6K ohm fixed resistor on the baro (only 94-95 and EGR?) This took my WG duty cycle to 85.9% at idle pot. off and 94.3% pot. on.


With this setup I get 6-7 psi no pot. and 10+ psi with. I saw it jump above 12 shifting between 3-4 gears but the other numbers are steady boost.


More than 5.6k ohms on the baro makes the wg duty cycle goes to 99.7% at idle. I ran empty with 94.7 % WGDC, today I'll try running with 99.7% WGDC to see if it makes more boost.


I figured it out. I had mistakenly installed 10 ohm resistors to little effect. I now have 11.2K ohms that's 2 x 5.6 k's instaed of the others and still 5.6K on the Baro.


This mornings empty run yeilded 9 psi without the pot. and the same with. The 11.2k ohms resistance gives me an idle reading of 1.20v down from 1.47v regular. Avg. running is pressure 2-5 psi.


I can hear more whislling than I ever have.


Edited by: quantum mechanic

Today, I switched the exhaust turbine housing on the 94. I could tell as soon as I looked at it what was wrong. I had been loosing exhaust pressure out of the turbine housing around the exhaust turbine.


I tapped the boss on the inside, toward the heatsheild and valve cover and put it all back together.


OK, now when I accelerate unloaded, the boost goes up to 15 psi then levels off at 10. In OD at 70 MPH I can sustain 12 psi. EGT's were climbing fast. 900- 1000 deg F after a few minutes of this. It sounds like a vacuum cleaner is on under the hood.Edited by: quantum mechanic

That 1000deg is 1000deg exhaust temperature out of the cylinders - you don't get no leeway with the tap located where it is.


Meaning - 1200deg is dangerous territory, time to tone it down a bit.


IAT will skyrocket between 10-15psi Boost - hopefully your probe is accurate, so Mother PCM can save your bacon where necessary.

I was thinking it's time to reconfigure the supercooler to sit where the airbox is and move the airbox to the ram air position.

I tried the 10k pot switch to see if i had any "gain" left in the MAP signal on top of the 11.2K fixed resistor. Pegging it I saw 15 psi peak and slowly level off to 13 psi back to 15 at the bottom of every gear. It hasn't given boost range codes since the baro resistor went in.

So what your saying is I should run down to radio shack and buy a ~11k ohm resistor for the Baro and a ~25k ohm pot for the MAP. What did all that hardware cost you? 10 bucks? count me in ;)

So what your saying is I should run down to radio shack and buy a ~11k ohm resistor for the Baro and a ~25k ohm pot for the MAP. What did all that hardware cost you? 10 bucks? count me in ;)


What are you gaining with these things? Reason I ask is because I get a code 78 every time I run down the interstate (75mph) ever since I dumped the vacuum pump and replaced it with a home-made "TurboMaster", and I think this may have something to do with it.


wade

Thats exactly why, the resistors cheat the sensors into telling the PCM you have less boost than you actually do so you in turn get more boost with the stock vacuum setup and no codes.

wade,


If you resist the map and baro (obdII doesn't have a seperate one and 95 can go either way) you won't see 78 anymore. The computer will forget about 78 and since it relates fuel to boost you'll gain what the computer would have taken away to lower the boost.

....QM, 6.5 ECMs do not relate fuel quanti**** to boost levels. Besides, if your cheating the input to the ECM, it still thinks your running stock boost levels anyway.

TDG,


I am now in favor of both the 10K pot. switch and 10K fixed with 5.6K fixed on baro, if you're using the vacuum set up. The pot. switch is just another 10K on top of everything and takes the WG duty cycle back toward 90 % under hard acceleration. if you're easy on the pedal you only see 1-2 psi difference


wade,


20k fixed on the map and 5K on the baro for mechanical spring-arm WG.