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What do you all think of these boost numbers???????

gnel

gnel

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Location
Jalisco,Mexico
I just installed a boost guage and here are some numbers. Hard acceleration from a standstill it will spike to 6 then quickly settle at about 4. Hard accel from about 45 mph it goes about 4 to 4.5. cruizing most speeds on level ground 1 to 2. Uphills 3 to 4. This is a stock vacuum setup. I have 25 inches of vacuum from the pump and 15 from the boost relay to the accuator. Thanks for any replys. g
 
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Thats low, even for a stock setup and program. Are you sure the gauge is correct or there isnt a break in the gauge line somewhere? Would be good to verify what the PCM is seeing from the boost sensor, or if it is the wrong boost sensor in it. Are you getting any black smoke?
 
I thought it was low also. I cut out the soot box awhile back. I am getting black smoke when I punch it but only for a few seconds. I just installed the guage and was very carefull. I have also just started noticing smoke coming out my dipstick? I talked with a friend of mine (very good Mexican shadetree diesel mech) and he said that a disfunctional turbo could cause the crankcase smoke. I don´t have any experiance with turbos so any help or thoughts on this are greatly appreciated. g

Ps I dont have any way to check the PCM Thanks again. g
 
I think your "crankcase smoke" translates to blowby, which is a term used to describe exhaust gasses going past rings in a worn engine.

open your oil filler tube, if it puffs out there as well, it is blowby. take note if it puffs. that means that one hole is worn significantly worse than the others.
 
Low I am not so sure on that, my truck is stock with a Heath 4" exhaust and crossover no kitty and she is give or take a PSI higher than that. Clean exhaust with the couple of second grey/black puff on hard accel and runs like a champ for a nearly stock setup.

Cruising 2-3
Hard sustained accel from slow 6 on the occasion she spikes to 9 if I get it just right
45mph then hard accel 5

From all that I have read over the years these figures jive with a stock setup.

No idea what she did before the exhaust change no gauge back then. As already noted in all reality just how accurate are these 50 dollar gauges more of a guide then an absolute in my book. As already posted too your exhaust colour is a good guide. Yes you may have a problem but I would not go losing sleep over it just yet.

This is your 95 burb? I would'nt be surprised by a wiff of blowby at 202,000

Cheers
Nobby
 
Or just hook vacuum pump straight to the wastegate actuator, works great and should prove both are working just fine.

I ran a stock "F" chip for a while and I could see 11-12psi sustained climbing hills, peaks a little higher. While cruising it should be low, but under load and hard acceleration could be hitting higher. Some 94/95 PCM programs really sucked on the timing curve and could also hurt boost performance. If you tell me the 4 letter code (like BPCH, always starts with B) off your EPROM I could tell you if its hurting you or not.
 
Mine ran WOT 7 when i first bought the truck. Then the wastegate solenoid died, so i went spring operated.
 
Thanks for all the replys. I´m gonna go try the direct from the pump suggestion. To show my 6.5 ignorance what and where is the EPROM I ? Let me know and I´ll go find the letter code. Thanks again.

Well I just got back from running it with the direct from pump trick. I got 18 under hard accel. Now does this mean everything is functioning properly?
 
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could be a small vac leak or a sticky selenoid or normal for the year. eprom is inside the PCM which is behind the glovebox
 
buddy the 4 letter code is BPAC (thanks ak diesel). Thanks for any info you can give me. g



buddy said:
Or just hook vacuum pump straight to the wastegate actuator, works great and should prove both are working just fine.

I ran a stock "F" chip for a while and I could see 11-12psi sustained climbing hills, peaks a little higher. While cruising it should be low, but under load and hard acceleration could be hitting higher. Some 94/95 PCM programs really sucked on the timing curve and could also hurt boost performance. If you tell me the 4 letter code (like BPCH, always starts with B) off your EPROM I could tell you if its hurting you or not.
Click to expand...
 
gnel said:
Thanks for all the replys. I´m gonna go try the direct from the pump suggestion. To show my 6.5 ignorance what and where is the EPROM I ? Let me know and I´ll go find the letter code. Thanks again.

Well I just got back from running it with the direct from pump trick. I got 18 under hard accel. Now does this mean everything is functioning properly?
Click to expand...

That says you got a good vac pump and wastegate actuator and gauge is probably pretty accurate. How did the truck feel with that boost? Depending on your programming it might just be that its a dog for that reason. Did you just pull the lines out of the solenod and connect them there?

Attached a picture of the PCM behind the glove box, and you can see the hatch on the back where the EPROM is located, its under one of the text boxes. You may or may not have to unplug the PCM connections. I can pull mine out without disconnecting it, but you might have to.
95 PCM in dash.jpgPCM clips and pegs.jpg
 
It felt stronger/quicker/good. I just pulled the vacuum hose from the solonoid and connected it to the accuator. I don´t know if you saw my prior post but my EPROM had a sticker on top of it with a bar code, a serial number and BPAC on it. Thanks again g
 
BPAC is a decent program, in most 95 subs. So I would think your boost is a bit low, since on that same program I could get some more boost.

You could have a slight leak in the vac line or the solenoid isnt working as well as possible, or if your boost sensor is a 3 bar sensor vs a 2 bar it might be telling the PCM more boost is there than actual.
 
This might be a dumb question. Could it be the wastegate accuator? I am getting 15 inches from the solenoid to the accuator but before I could not manully move the accuator bar at idle and now I can. Its stiff but movable. Sorry if these questions are tiresome. Thanks g
 
It's movable, but like NVW said it should be very stiff and take considerable amount of pressure to move it.....and if the turbo is hot you'll burn your finger trying to push it down.....or at least thats what my experience has been.
 
The actuator is holding it closed with full vacuum so you could reach 18psi, so I would not suspect it right now. I would inspect the boost sensor to see if the wrong one is installed, commonly a 3 bar that looks the same will be put on by mistake.
 
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