S15 boost problems?

Yakozan · 01-08-2005, 13:56

Hi.
I've been a happy S15 driver for a month now and started to notice wierd things with the boost.

When I first got the car (and after I fixed the leaking exhaust),
the car boosted -0.2 bar with no gas and about 0.55-0.65 bar with pedal to the metal.
Is this the correct boost for an S15 with 3" downpipe and cat-back?

A couple of days ago (after changing engine oil) I noticed that the boost with no gas was -0.1 bar and about 0.4 bar with full throttle.

All the boost figures was checked with the standard factory boost gauge.
Whats wrong?
Clogged air-filter?

I'm currently running the car on 98 RON (best quality available in Sweden)
Could it be the ECU changing the boost for the lesser quality fuel?
It boosted fine for 3000km

Please help me.
The car feels a little less powerfull now compared to before

Best regards
Paul

Nicely · 01-08-2005, 14:27

Clogged air filter would be mean running rough at tickover (starved of air). Unlikely to be the fuel.

Check all IC and boost hoses are tight.
Check if you can move the actuator arm.
Check for cracks in the WMIC.

You could try an ECU reset too. Disconnect the battery and turn you lights on, then reconnect.

Yakozan · 01-08-2005, 14:53

Quote:

Originally Posted by Nicely

Clogged air filter would be mean running rough at tickover (starved of air). Unlikely to be the fuel.

Check all IC and boost hoses are tight.
Check if you can move the actuator arm.
Check for cracks in the WMIC.

You could try an ECU reset too. Disconnect the battery and turn you lights on, then reconnect.

Ok.
Sorry i'm a little new to the technical pats of cars. How does the actuator arm look like and where is it located?

best regards
Paul

Nicely · 01-08-2005, 15:03

Find the turbo under the heat shield (you don't need to take the heat shield off). The actuator is the cylindrical thing bolted to the turbo with a long metal arm sticking out of the side of it. You will probably need long nosed pliers to grip the arm. Try to pull the arm out of the actuator (to the right). If you can move it reasonably easily (but still stiff), its probably on its way out. You shouldn't be able to pull the arm out.

Yakozan · 01-08-2005, 15:18

Quote:

Originally Posted by Nicely

Find the turbo under the heat shield (you don't need to take the heat shield off). The actuator is the cylindrical thing bolted to the turbo with a long metal arm sticking out of the side of it. You will probably need long nosed pliers to grip the arm. Try to pull the arm out of the actuator (to the right). If you can move it reasonably easily (but still stiff), its probably on its way out. You shouldn't be able to pull the arm out.

Thx.
I'll check when I get home from work.

Got a reply from Nissansilvia.co.nz to. A guy there though that it was the boost gauge pipe leaking. Will try to look into that to.

http://www.nissansilvia.co.nz/phpBB2...ic.php?t=12215

best regards
Paul

Topper · 01-08-2005, 16:33

Thats what i was going to suggest, seen stories of them not being the greatest

Nicely · 01-08-2005, 16:44

Forgot that. The pipe splits easily. Mine had when I got it.

You can't miss it. Its the pipe that runs from the boost sensor mounted on the drivers front strut to the hose going to the recirc valve.

Yakozan · 01-08-2005, 17:57

Just went outside and had a look.
It wase the hose which had splitted at the drivers side front strut.
Will get a new one and hope it solves the problem, which it hopefully should do.

But could that little hose cause such a big boost drop?
It was probobly broke when I got the car cause I always thought a peak at 0.55 (0.7 once) Bar was a little low considering the 3" front-pipe and cat back exhaust. 0.7 Bar seems to be more accurate.

Thanks for all the help

best regards
Paul

Nicely · 01-08-2005, 18:31

At the pressures involved: yes.

Yakozan · 01-08-2005, 21:56

WOOHOO

I now get 0.8 Bar in boost.
The car is like new.... Now I need Naaaaws.

Thanx for the help. The car will now be impossible to drive in the rain

best regards
Paul

Greg · 02-08-2005, 08:42

I had the same problem a while back - it cost me £50 to get it fixed - which was 1hrs labour at Turbotechnics. How I didn't find the leak I don't know - suppose its a learning curve!
Now we all know thnks to the wise words of Nicely!

Yakozan · 02-08-2005, 10:33

Quote:

Originally Posted by Greg

I had the same problem a while back - it cost me £50 to get it fixed - which was 1hrs labour at Turbotechnics. How I didn't find the leak I don't know - suppose its a learning curve!
Now we all know thnks to the wise words of Nicely!

50£ and 1h labor!

I hope it wasn't the same hose as on mine.
The hose costed 0.5£ in a well sorted gas station and it took like 5 seconds to pull the broken one out and 10 seconds to put the new one in.
But the most important thing is that the car works properly.

Best regards
Paul

Nicely · 06-08-2005, 10:27

Well, my pipe split again yesterday while out with Jez.

I would strongly recommend doing what I did if you intend keeping the stock gauge.

I replaced the entire boost hose with a silicon and plumbed it directly to the boost sensor. I'll just T of this new hoes as and when I need to.

You will need to put an inner hose on the sensor nipple (I used washer jet hose) then put the silicon over it.

bettsc · 27-08-2005, 10:47

I've had this hose split also - twice ! First time there was enough length to cut it back & push on again, but recently it went a second time.
Got the Nissan part from my main dealer in three weeks (part number is 25095-80F00 Hose-Vacuum). Cost was £13 + VAT. Let's see how long this one lasts !

Nicely · 27-08-2005, 11:35

You really shouldn't have wasted your money. It will split again guaranteed. Mine split twice in two months. It happens to most people if you check out the Oz and NZ Silvia BBs.

You'd have been better getting a 1 metre length of Samco silicon boost hose from Bren for £2.50 and did what I did ^^^. Bet money that mine never needs touching again.

01-08-2005, 13:56	#1
Yakozan Guest Join Date: Mar 2005 Location: Sweden Posts: 752	S15 boost problems? Hi. I've been a happy S15 driver for a month now and started to notice wierd things with the boost. When I first got the car (and after I fixed the leaking exhaust), the car boosted -0.2 bar with no gas and about 0.55-0.65 bar with pedal to the metal. Is this the correct boost for an S15 with 3" downpipe and cat-back? A couple of days ago (after changing engine oil) I noticed that the boost with no gas was -0.1 bar and about 0.4 bar with full throttle. All the boost figures was checked with the standard factory boost gauge. Whats wrong? Clogged air-filter? I'm currently running the car on 98 RON (best quality available in Sweden) Could it be the ECU changing the boost for the lesser quality fuel? It boosted fine for 3000km Please help me. The car feels a little less powerfull now compared to before Best regards Paul __________________ Nissan Silvia S15 Spec-R -99 Mazda RX-7 FD -94 Nissan GT-R -09 (not mine, but pretty darn close )

01-08-2005, 14:27	#2
Nicely Trainee Finn Join Date: Jan 2003 Location: Helsinki, Finland Posts: 17,166	Clogged air filter would be mean running rough at tickover (starved of air). Unlikely to be the fuel. Check all IC and boost hoses are tight. Check if you can move the actuator arm. Check for cracks in the WMIC. You could try an ECU reset too. Disconnect the battery and turn you lights on, then reconnect. __________________ Surf's up!! S14/S15 Tech Guides Now departed S15

01-08-2005, 15:03	#4
Nicely Trainee Finn Join Date: Jan 2003 Location: Helsinki, Finland Posts: 17,166	Find the turbo under the heat shield (you don't need to take the heat shield off). The actuator is the cylindrical thing bolted to the turbo with a long metal arm sticking out of the side of it. You will probably need long nosed pliers to grip the arm. Try to pull the arm out of the actuator (to the right). If you can move it reasonably easily (but still stiff), its probably on its way out. You shouldn't be able to pull the arm out. __________________ Surf's up!! S14/S15 Tech Guides Now departed S15

01-08-2005, 16:33	#6
Topper Guest Join Date: Feb 2005 Location: Aberdeenshire Posts: 2,508	Thats what i was going to suggest, seen stories of them not being the greatest __________________

01-08-2005, 16:44	#7
Nicely Trainee Finn Join Date: Jan 2003 Location: Helsinki, Finland Posts: 17,166	Forgot that. The pipe splits easily. Mine had when I got it. You can't miss it. Its the pipe that runs from the boost sensor mounted on the drivers front strut to the hose going to the recirc valve. __________________ Surf's up!! S14/S15 Tech Guides Now departed S15

01-08-2005, 17:57	#8
Yakozan Guest Join Date: Mar 2005 Location: Sweden Posts: 752	Just went outside and had a look. It wase the hose which had splitted at the drivers side front strut. Will get a new one and hope it solves the problem, which it hopefully should do. But could that little hose cause such a big boost drop? It was probobly broke when I got the car cause I always thought a peak at 0.55 (0.7 once) Bar was a little low considering the 3" front-pipe and cat back exhaust. 0.7 Bar seems to be more accurate. Thanks for all the help best regards Paul __________________ Nissan Silvia S15 Spec-R -99 Mazda RX-7 FD -94 Nissan GT-R -09 (not mine, but pretty darn close )

01-08-2005, 18:31	#9
Nicely Trainee Finn Join Date: Jan 2003 Location: Helsinki, Finland Posts: 17,166	At the pressures involved: yes. __________________ Surf's up!! S14/S15 Tech Guides Now departed S15

01-08-2005, 21:56	#10
Yakozan Guest Join Date: Mar 2005 Location: Sweden Posts: 752	WOOHOO I now get 0.8 Bar in boost. The car is like new.... Now I need Naaaaws. Thanx for the help. The car will now be impossible to drive in the rain best regards Paul __________________ Nissan Silvia S15 Spec-R -99 Mazda RX-7 FD -94 Nissan GT-R -09 (not mine, but pretty darn close )

02-08-2005, 08:42	#11
Greg NON-MEMBER Join Date: Aug 2003 Location: Dooooorrrrrseeeeetttt Posts: 172	I had the same problem a while back - it cost me £50 to get it fixed - which was 1hrs labour at Turbotechnics. How I didn't find the leak I don't know - suppose its a learning curve! Now we all know thnks to the wise words of Nicely! __________________ Did you see that??

06-08-2005, 10:27	#13
Nicely Trainee Finn Join Date: Jan 2003 Location: Helsinki, Finland Posts: 17,166	Well, my pipe split again yesterday while out with Jez. I would strongly recommend doing what I did if you intend keeping the stock gauge. I replaced the entire boost hose with a silicon and plumbed it directly to the boost sensor. I'll just T of this new hoes as and when I need to. You will need to put an inner hose on the sensor nipple (I used washer jet hose) then put the silicon over it. __________________ Surf's up!! S14/S15 Tech Guides Now departed S15

27-08-2005, 10:47	#14
bettsc NON-MEMBER Join Date: Feb 2004 Location: Plymouth area Posts: 21	I've had this hose split also - twice ! First time there was enough length to cut it back & push on again, but recently it went a second time. Got the Nissan part from my main dealer in three weeks (part number is 25095-80F00 Hose-Vacuum). Cost was £13 + VAT. Let's see how long this one lasts ! __________________ Chris

27-08-2005, 11:35	#15
Nicely Trainee Finn Join Date: Jan 2003 Location: Helsinki, Finland Posts: 17,166	You really shouldn't have wasted your money. It will split again guaranteed. Mine split twice in two months. It happens to most people if you check out the Oz and NZ Silvia BBs. You'd have been better getting a 1 metre length of Samco silicon boost hose from Bren for £2.50 and did what I did ^^^. Bet money that mine never needs touching again. __________________ Surf's up!! S14/S15 Tech Guides Now departed S15