R32 Gtst Struggles To Rev When On Boost

[quink]

Hi all,

My car got a little hot the other day, so i did a full cooling system check. removed and fully flushed radiator/changed thermostat/changed viscous fan. Did the job pretty straightforward everything seems ok. Car starts/idles fine.

So went out for a drive to check everything when it was warmed up again problem strikes.

Now while on boost from 3500-7000rpm the car struggles heaps to get the revs up (but it does go up very slowly). I can see the stock gauge go up to full boost (from where it was at before i did the change). After a few more times trying, on full throttle, at 3500rpm-5000rpm with the revs struggling to climb, it starts jerking like boost coming on and off. so I let go and try again, same thing. Let the car cool down.. took out battery, hit brake for a few minutes, (to reset ECU) then tried again. same issue.

Then I try with half throttle with the stock boost gauge on 0 , the car revs up fine (goes up to 6000rpm) no problem. but everytime there's a bit of boost the car struggles.

So i figure its some sort of boost problem, now how the hell does this happen if i've only touched the simple cooling system. Everything worked hunky dory before this.

Not much knowledge as yet about the whole vacuum system and how it works. but are there any hoses i should check that sit near the bottom radiator hose? when taking the viscous fan off i had to undo the alternator fan/water pump belt.. didn't undo any other belts. Plugged and unplugged the water temp sensor. that seems fine.

Does anyone have any ideas?

Thanks in advance.

Mods are

Cat back exhaust

Mines ECU (i think the boost is slightly higher on these guys)

Apexi air filter

rest is stock as a rock

[skylinekid]

when u say it goes up slowly... does it seem as if the car is running really rich when u hit the gas? the only thing i could possibly link to it after gettin hot possibly stuffed the coolant temp sensor. ive only ever really seen one go and that was on a ford falcon. same symptoms. when cold, system is rich. rich is justified for cold motor. but once hot the extra fuel will cause it to overfuel etc. anyways its a good start i guess.

Edited December 17, 2008 by skylinekid

[quink]

when u say it goes up slowly... does it seem as if the car is running really rich when u hit the gas? the only thing i could possibly link to it after gettin hot possibly stuffed the coolant temp sensor. ive only ever really seen one go and that was on a ford falcon. same symptoms. when cold, system is rich. rich is justified for cold motor. but once hot the extra fuel will cause it to overfuel etc. anyways its a good start i guess.

if the coolant temp sensor was gone, would it still show a reading of water temp in the car? coz that's still working on the halfway point or just below. that's the guy on the bottom right radiator right (from the drivers position)

and it seems to want to rev when off boost.. not sure what running rich feels like.. but its not backfiring or anything after i lift off.. i do have an A/F meter on the turbo timer i can give that a check..

oh just want to note that when the car got hot, i turned on the heater to full straight away and the temp came back to normal..

and by struggling it means if i'm at full throttle, it struggles so much and goes up so slowly that its like literally 20% power..

i also dont hear knocking, turbo rush noise from airpod sounds the same, stock boost gauge acts the same..

everything sounds the same but the rpm just doesn't want to climb.. and as soon as i lift off i get a surge in power.

i also bled the cooling system for awhile but bubbles in the system will just make the system get hot right rather than cause significant boost issues?

Edited December 17, 2008 by quink

[neo32]

the one on the bottom of radiotor activates the air con fans i think

the one for the gage and ect tthere is 2 more

are up by the left hand side front of head where whe water exits out going back to the radiotor

there is 2 there the single pin is the guage on the dash

the bigger more expensive 2 pin is for the ecu

good luck

[quink]

the one on the bottom of radiotor activates the air con fans i think

the one for the gage and ect tthere is 2 more

are up by the left hand side front of head where whe water exits out going back to the radiotor

there is 2 there the single pin is the guage on the dash

the bigger more expensive 2 pin is for the ecu

good luck

hrm.. i did spray that area with water to wash the coolant dripping off the bleeder hole..

anyone know any detrimental effects if i unplug it and run the engine? and would it feel a lot different under normal circumstances?

i.e. i was thinkin if i unplug ECU one.. rev it and it feels exactly the same. i can deduce that it could be the problem? or if i unplug it and

it feels different .. then i know its not the problem? lol .. ghetto problem solving.

[skylinekid]

well to tell if its rich... look out the back for ne sort of black smoke.... exhaust note will sound different to normal as in from experience it would sound very deep like a drone..... short of that mate without being near the car to hear it im not sure...

yes that is one way of checking it... BUT ive done that b4 and the car ran different but in the end it still ended up being the coolant temp sensor... and if u sprayed water over the motor i just had a thought of maby u flooded the coils with water.... give that a check aswell

also just by chance.... to have changed the viscous fan hub if u have a front mount u would have taken off intercooler pipes..... check ur connections all round if so.

Edited December 17, 2008 by skylinekid

[quink]

well to tell if its rich... look out the back for ne sort of black smoke.... exhaust note will sound different to normal as in from experience it would sound very deep like a drone..... short of that mate without being near the car to hear it im not sure...

yes that is one way of checking it... BUT ive done that b4 and the car ran different but in the end it still ended up being the coolant temp sensor... and if u sprayed water over the motor i just had a thought of maby u flooded the coils with water.... give that a check aswell

also just by chance.... to have changed the viscous fan hub if u have a front mount u would have taken off intercooler pipes..... check ur connections all round if so.

Thanks for the help guys keep the ideas comin!

nah didn't take off any intercooler pipes.. got stock IC.. yeh it was dark by then so i checked via torchlight.. will check again this arvo..

oo oo.. just thought of something else.. when i removed the radiator with cowling and fan.. its pretty tight on a bottle(no idea what that is) on the right side and some pipes.. and when putting it back in we struggled to slot it in for awhile potentially pushing against those items next to the radiator..

is there anything there that can affect boost?

Edited December 17, 2008 by quink

[tridentt150v]

I'll say I haven't read the whole thread..........

But did you bleed your coolant system? sounds like you have air in the system.

[quink]

I'll say I haven't read the whole thread..........

But did you bleed your coolant system? sounds like you have air in the system.

yes. ran the car. left the top bolt off (where it says do not remove when hot) and radiator cap off... ran for 20min to get coolant flowing.. then plugged rad cap up.. let it bubble out more.. it never really stopped bubbling tho, revved it.. let the liquid flow out (still had tiny bubbles in it .. i wouldn't call it a continous flow of green) plugged it up while the hole was full. but i reckon if i took it off.. there'd still be bubbles in it.. it seems to suck air in the hole when idling with the bolt off.

isit meant to be solid continous liquid coming out? coz it never seemed to do that even after 20min.. might try again tonite..

but can air pockets in coolant cause such a significant boost issue?

Edited December 18, 2008 by quink

[skylinekid]

shouldnt be causing a boost issue problem but the correct way to bleed the system is to take that bolt out and get a funnel that suite the radiator and pour water into it and because its higher then the radiator it will force the extra air out of the system. then u put th bolt back in after a steady flow of coolant comes through. then u start car and turn heater on full so it circulates throught the whole system. once thermostat has opened top up the water and replace cap. make sure overflow has sufficient water and ur good to go. neways blah blah....

[shy_s6]

sounds like its breaking down tho,,, any chance u got water on the cas, coilpack loom, coil packs?

[quink]

sounds like its breaking down tho,,, any chance u got water on the cas, coilpack loom, coil packs?

i doubt that.. i only splashed to the side of the plenum and below.. but i wouldn't discount it.. i'll be checking that.

Edited December 18, 2008 by quink

[quink]

i doubt that.. i only splashed to the side of the plenum and below.. but i wouldn't discount it.. i'll be checking that.

an update.. got to my car which was cold.. opened up the bolt, and no liquid flowed out.. i'm like hrm.. there should be no air in there right?

did the.. noticed one of the lines had crusty sludge in it.. took it out cleaned it.. then fill up via radiator cap.. start the car running.. closed cap, and squeezed radiator hose until all the air came out and no more bubbles.. closed the bolt.

problem still occured.... an interesting thing is that when i turned the heater on full hot, i could boost abit (albeit still jerky)

Also looking at the A/F ratio on turbo timer (i know its not accurate) it was running way RICH.. on 18 instead of 12 (from before)

if i listen closely to the vacuum bottle (with the vc surge sticker) on the right of the radiator i hear a slight squeel.. is there a puncture in a hose or something? is it meant to squeel? when i throttle it it squeels a little louder then the pssshhht noise although at this point i'm not sure if its from the bottle itself.

[quink]

an update.. got to my car which was cold.. opened up the bolt, and no liquid flowed out.. i'm like hrm.. there should be no air in there right?

did the.. noticed one of the lines had crusty sludge in it.. took it out cleaned it.. then fill up via radiator cap.. start the car running.. closed cap, and squeezed radiator hose until all the air came out and no more bubbles.. closed the bolt.

problem still occured.... an interesting thing is that when i turned the heater on full hot, i could boost abit (albeit still jerky)

Also looking at the A/F ratio on turbo timer (i know its not accurate) it was running way RICH.. on 18 instead of 12 (from before)

if i listen closely to the vacuum bottle (with the vc surge sticker) on the right of the radiator i hear a slight squeel.. is there a puncture in a hose or something? is it meant to squeel? when i throttle it it squeels a little louder then the pssshhht noise although at this point i'm not sure if its from the bottle itself.

um after some reading.. its running way lean?? yech..

edit: hrm.. based off an O2 sensor? and is a theoretical value? after some further reading it sounds like my car fits the R&R mode. but isit doing the fuel cut thing? what happens besides things exploding when you run very lean? would it act as i described above?

Edited December 18, 2008 by quink

[quink]

great now the car won't start . it was a pretty warm day and it was sitting outside. cranks fine but no ignition...

I heard the fuel pump prime... sounded not as nice a whiney sound as usual... coils? anyone can fit all the symptoms together?

time to bring to a shop I think

[quink]

great now the car won't start . it was a pretty warm day and it was sitting outside. cranks fine but no ignition...

I heard the fuel pump prime... sounded not as nice a whiney sound as usual... coils? anyone can fit all the symptoms together?

time to bring to a shop I think

just fyi.. it was my fuel pump, the fuel pump prime noise was obviously something else i was hearing..

Exchanged it for a Walbro 500hp unit.. car starts perfectly.. boosts better than ever! revs all the way up to 8k with NO issues no hesitations no signs of pinging... aww i'm in love with the car again!

[mbwilding]

just fyi.. it was my fuel pump, the fuel pump prime noise was obviously something else i was hearing..

Exchanged it for a Walbro 500hp unit.. car starts perfectly.. boosts better than ever! revs all the way up to 8k with NO issues no hesitations no signs of pinging... aww i'm in love with the car again!

I had the exact same problem exept my R33 wont start still, Error code 13, Apparently my fuel pump pumps to much fuel is this possible?

[StealthX]

hmmmmmmmmm strange!

good to hear your got it fixed bro!

just a weird coincidence that your fuel pump died the same time that you did your coolant flush...

[PEZESD]

Hi guys i have a r33 and i just replaced the water line that sits directly under the inlet manifold with six bolts. I put everything back together and kicked it over but i wont start. I can smell fuel from the exhaust so i know its not a fuel problem. As for spark i had a coil pack problem so i replaced the coils around 15-20,000 k's ago with split fires. I've checked everything twice but cannot see anything. Can anyone shine some light please.

[GTScotT]

man those little turbo timers are handy! they arent accurate but atleast you know when your leaning out

good to see you fixed it mate