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Post by dsuguitan on Sept 9, 2007 1:36:22 GMT 11
... greetings to all.. i,ve recently installed a boost gauge and T'd to the hose going to the intercooler.. my question is, at idle (gear selector at park) when you rev the engine, the needle at my gauge hardly moved, up until 3000 rpm where it went up to 1 psi.... is this normal?.. when i took the car for a spin, the neeedle indicated a 1 psi boost at 1500rpm, then 2 psi at 1800rpm, then 3 psi at 2100 rpm.. is this okay?.. i have a 3.1 Mu Auto with a top mounted IC ( with a scoop), K&N filters and took out the EGR's... thanks in advance..
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Post by muvit madness on Sept 9, 2007 10:37:21 GMT 11
hi & welcome to the forum  it is normal if your stationary & you rev the engine to only generate minimal boost as your not actually loading up the turbo. but in saying that the second you accelerate it should be up on boost around the 11psi mark for standard untouched turbos?. if yours is only generating 3 psi @ 2100 whilst driving then you have a problem?. 1 is your turbo spooling up as you drive?, 2 recheck the boost line to the gauge hasn't a pin hole in it & is correctly attached? 3 check the turbo & I/C hoses are tightly clamped. any oil residue around fittings & gaskets is a sign of leaking boost pressure. try these. cheers muvit  |
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Post by dsuguitan on Sept 9, 2007 15:28:21 GMT 11
...thank you for the quick reply.. i'll check on all three later.. before anything else, i'd like to express my appreciation to this forum.. i followed most of the suggestion here and my MU is running pretty well..i,ve done the egr, installed manual locking hubs, changed my diff to an LSD, and recently just installed a top mounted IC..i live in the philippines and there's a lot of surplus JDM isuzu parts here.. thanks for all the help
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beau
Isuzu Baby
green just doesn't cut it
Posts: 37
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Post by beau on Sept 9, 2007 17:28:45 GMT 11
...thank you for the quick reply.. i'll check on all three later.. before anything else, i'd like to express my appreciation to this forum.. i followed most of the suggestion here and my MU is running pretty well..i,ve done the egr, installed manual locking hubs, changed my diff to an LSD, and recently just installed a top mounted IC..i live in the philippines and there's a lot of surplus JDM isuzu parts here.. thanks for all the help you may also want to TEE the boost gauge via the waste gate actuator line which is part of the standard turbo housing... there is a reason they put it there, phyisic's dictates that the further from the source the weaker it gets, closer to the turbo the more acurate it will be, however it is up to you whether you chose to get the reading from the turbo or the reading at the manifold is up to you.?. stock standard mitsubishi evolutions run 11 psi standard not isuzu diesils. sorry for any contradiction but thats an obvious one..  |
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Post by geeves on Sept 9, 2007 19:45:54 GMT 11
My 2.8 shows 14 psi max boost if the gauge is connected to the same intercooler pipe via a T piece with a restrictor in it but 17 psi if conected directly. Conected like this though means no boost compensation for the fuel pump and also a very shaky needle at idle. Diesels nearly always run higher boost than petrols as they dont have problems with preignition etc. Its unusual for standard petrol cars to run more than 4 or 5 psi but evos are really a race car. I know of an evo running 26psi but 30000 has been spent on mods to that car
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Post by muvit madness on Sept 9, 2007 22:55:17 GMT 11
you may also want to TEE the boost gauge via the waste gate actuator line which is part of the standard turbo housing... there is a reason they put it there, phyisic's dictates that the further from the source the weaker it gets, closer to the turbo the more acurate it will be, however it is up to you whether you chose to get the reading from the turbo or the reading at the manifold is up to you.?. stock standard mitsubishi evolutions run 11 psi standard not isuzu diesils. sorry for any contradiction but thats an obvious one.. [/quote]  dude the obvious one is dsugitan hasn't got a mitsubishi evo but has a problem with his 3.1 reaching more than 3psi boost. most mus i know run AROUND 11psi until he/she alters the boost. |
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quack
Isuzu Senior
Posts: 220
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Post by quack on Sept 13, 2007 15:40:40 GMT 11
unless its hooked up wrong there shouldnt be any diff weather you take it from turbo or manifold, i have mine coming from the intercooler makes it easyer to fit the boost tap.
my 2.8 was running 10psi standard, now running 14
it should make full psi at 2000rpm, they also dont vac...
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Post by dsuguitan on Sept 14, 2007 0:57:39 GMT 11
..greetings... thank you for your replies and inputs.. update on my boost problem, as Muvit Madness suggested, i've checked all hoses from the from the turbo inlet/outlet to the IC, it was tight no apparent leaks, i,ve checked also the hose from the boost gauge to the inlet hose to IC where I T'd it, it was tight and snug also, no kinks also.. i,ve been observing the engine response for a while, it boosted to 6 psi at 2500rpm, my speed was 75km, it was an uphill climb (around 4-5 degrees according to my inclinometer) with one passenger.. no black smoke.. i'm still looking for any air leaks that's causing the low boost pressure.. could it be my intercooler has a small hole?.. would it make a whistling sound under boost coz i noticed none.. the engine response was a lot briskier since I installed the topmounted IC ( with scoop) around 2 weeks ago, fuel consumption is around 10-11 kms/l highway driving, my engine has done 190000.. will talk to the diesel calibration guy who did my injection pump 2 years ago coz he i remembered he mentioned he set the boost at 7 psi.. i'll keep you guys posted.. thanks in advance
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beau
Isuzu Baby
green just doesn't cut it
Posts: 37
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Post by beau on Sept 14, 2007 19:41:43 GMT 11
ok since my last post i have discovered the actuator spring in my truck wasnt operating correctly and the wastegate opening sooner than it should, my apologise to muvit and any other members for any contradiction i have made
personal expierience has proven (for my truck) that the gauge was reading more accurately(steady) tee'd from the turbo side of the intercooler.
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Post by muvit madness on Sept 15, 2007 0:38:07 GMT 11
hi dsuguitan have you tried doing what geeves mentioned & disconnecting the hose from the aneroid compensator so as to get full boost out of her. Then see how much boost you get then  . if she boosts pass the set 7psi your referring to & say for arguments sake hits 17 psi then your quick fix will be to tee a adjustable boost controller inline on the disconnected hose, which i can tell you from personal experience is one of the best things i done for my mu. on the other hand if there's still no gain after the disconnection of the boost hose then wind your wastegate in 1 or 2 turns if it has a adjustable nut on the shaft. as this is done as a more permanent boost fix i.e the 7psi your referring too.as opposed to using a boost controller. cheers muvit |
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Post by dsuguitan on Sept 15, 2007 3:01:28 GMT 11
.. okay, thanks for the inputs.. i've cleaned the IC today and replaced the metal cover and applied an asbestos liner where my EGR's used to be because i noticed some gray soot, ( possibly a source of leak).. still didn't boost pass 6 psi at 2500.. I'll try Alan's suggestion and use a T- piece without a restrictor and see how it goes.. i'll keep you guys posted.. thanks..
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Post by dsuguitan on Sept 16, 2007 0:38:15 GMT 11
... greetings again.. tried Alan's suggestion and T'd the boost gauge without a restrictor, still no improvement in boost, didn't go pass 6 psi at 2500rpm.. will try Muvit Madness's suggestion of adjusting the nut of the wastegate.. just a couple of questions though,1. in turning the nut at the shaft of the waste gate, would it be clock wise or counter clock wise? 2. in increasing my present boost, would i also adjust the fuel delivery at the injection pump?... or 3. would i adjust the boost from the injection pump ( that means removing the whole injection pump and bench calibrating the boost to say 10 psi? ) .... in which order should I approach this? ( adjust the waste gate or bench calibrating the injection pump).... thanks again for your replies and inputs...
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Post by geeves on Sept 16, 2007 8:14:11 GMT 11
The pump auto compensates for boost up to about 15psi. Even if it doesnt diesels dont have a fixed mixture as such so it will still go ok. Unless yours is electronicly controled we can worry about fuel later. If electronic we dont have to worry as we cant change anyway.
As a first test remove the pipe between wastegate and turbo and seal both ends securly but this is only for a test. Give it a quick drive and you should see boosts up to 16ish. If this is good we can carry on if not you have a problem that needs to be addressed. I trust the guage is working correctly. To adjust turn the nut one way half a turn If boost goes down turn the other way. Aim for a figure between 10 and 13psi with full throttle and revs around 2200.
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Post by dsuguitan on Sept 16, 2007 14:27:06 GMT 11
... hello... will try your suggestion and i'll let you know what happens.. thanks alan...
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Post by dsuguitan on Sept 16, 2007 14:39:13 GMT 11
...checked the injection pump, i idon't think it's electronic (drive by wire) coz i replaced the accelerator cable 2 years ago... took the MU for a drive a while ago, still 6 psi ( 2750rpm at 120 km/hr).. will try to disconnect the waste gate later, let the engine cool down a bit..... thanks again
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Post by dsuguitan on Sept 18, 2007 23:27:31 GMT 11
... hello.. tried alan's suggestion of disconnecting the wastegate hose and sealing both ends ( turbo side/ waste gate side).. still didn't go pass 6 psi at 2600rpm, in addition, there was a loud whistling sound, starting at 2000rpm (2 psi), then getting more prominent until it reaches 2600 rpm (6psi). decided to rev the engine at idle, but the whistling sound was not as prominent. i used bolts to seal both ends of the tube and checked if it was coming from there, it didn't... hmmmm.. in addition i also noticed oil residues at the turbo outlet when i removed the IC 2 days ago, thought that was where i was leaking boost, so i tightened it. still no boost improvement.. do i have a busted turbo?.. or a leak somewhere?... thanks again for all your inputs...
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quack
Isuzu Senior
Posts: 220
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Post by quack on Sept 19, 2007 16:50:18 GMT 11
if it sounded like it was boosting harder then i would say your gauge could be faulty?? basicly by removing that pipe it should just keep spolling up well into the 20psi range. can u get another gauge to test it.
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Post by dsuguitan on Sept 19, 2007 17:17:22 GMT 11
... hello.. will try to get a better brand, the one i bought was " auto gauge" a taiwanese brand... i think it was a knock off design of the american brand " auto meter" which looks exactly the same... was the whistling i heard was the turbo boosting more or a sign of leaking boost somewhere?... thanks again..
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quack
Isuzu Senior
Posts: 220
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Post by quack on Sept 19, 2007 17:42:19 GMT 11
um hard to say i noticed that when i went from 10psi to 14psi it made more turbo noise, but its the turbo spool noise.
a few months ago after playing with my IC pipes and left it a bit loose when i went for a drive it came loose and started leacking but i could tell it was a leacking sound straight away.
does it smoke blue at all? and have you checked the compresser wheel for play? you can check just by taking the intake pipe off the turbo.
other wise if you think its leacking then strat from the turbo and make your way up the intake to the motor cheaking that theres nothing loose.
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quack
Isuzu Senior
Posts: 220
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Post by quack on Sept 19, 2007 17:43:08 GMT 11
oh and yeah ive had a mate with a boostgauge like urs and was faulty brand new
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dude the obvious one is dsugitan hasn't got a mitsubishi evo but has a problem with his 3.1 reaching more than 3psi boost. most mus i know run AROUND 11psi until he/she alters the boost.
. if she boosts pass the set 7psi your referring to & say for arguments sake hits 17 psi then your quick fix will be to tee a adjustable boost controller inline on the disconnected hose, which i can tell you from personal experience is one of the best things i done for my mu. on the other hand if there's still no gain after the disconnection of the boost hose then wind your wastegate in 1 or 2 turns if it has a adjustable nut on the shaft. as this is done as a more permanent boost fix i.e the 7psi your referring too.as opposed to using a boost controller.