Defgeph

#1

From the begining of my swap I've had low vac issues. I replaced hoses tightened everything up capped off holes.

I eliminated my AC and power steering. I have the hose for the AC idle up capped. Would I be better off capping the two PS vac lines?(current setup) Or should I connect them to each other with a hose. I'm close to having full vac, but its still alittle off.

Second thing, when I slow down and put the car into neutral the RMP's dip way below normal idle. After running at like say 650-750 rpm for a few seconds, it raises back to 1000 where its been since the begining of this project. Sometimes the car stalls, I looking for some suggestions or ideas.

I've checked timing, its set at 10d's.


Thanks guys

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95celgt

#2

man, for some reason my 3s has crappy vac as well, when I did the re-build i changed every vac hose and it still sucks, when i turn it on its only at 10vac and once it warms up the best it does is 15 vac, so im still trying to figure out if the ecu or something like a vsv or afm can affect it this bad........

lagos

#3

did you ever do a boost leak test?

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15PSI - 30MPG - Megasquirt Tuned

alltracman78

#4

A boost leak won't affect idle quality at all.
A vacuum leak will however.

Jeff, if you join those 2 hoses you will raise your idle.
One gets air from before the TB [intake hose] while the other runs off the intake manifold.
Basically you will be creating a second ISC valve, but with no valve.

For both of you, how does the needle in the gauge look?
Is it steady at low pressure or does it jump around some?

If it's steady it's more of a general problem, such as a weak coil, or vacuum leak. Or a worn out engine.
If it's jumping around it's more likely to be from 1 cylinder, such as a bad plug, worn ring, or bad seal on a valve.

lagos

#5

>

QUOTE

>A boost leak won't affect idle quality at all.
A vacuum leak will however.

a boost leak test will find leaks in the system. from vac lines to IC couplers. any vac/boost leaks on a 3s will play a big role in how the car idles, because youll always be sucking in air that the afm cant account for.

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15PSI - 30MPG - Megasquirt Tuned

x_itchy_b_x

#6

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QUOTE(alltracman78 @ May 7, 2007 - 7:39 AM) [snapback]554901[/snapback]

>
A boost leak won't affect idle quality at all.
A vacuum leak will however..

That sounds like an oxymoron,

Jeff, what is your vacuum at idle? it should be around 18-20 Hg with stock cams.
I only have 10 Hg vacuum at idle but thats because of the cams.
also if your going by the marks on the crack to determine timing it might be wrong.
my crank pulley was around 4 degrees off from tdc.
But it does sound like a boost/vacuum leak ( Depending if you boosting or at idle )

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Defgeph

#7

I've done the boost leak test. I'm almost sure I dont have any major leaks. I have a very small leak now. I just cant seem to find it.

Whats funny is that I disconnected my Autometer boost gauge. After that my vac was perfect. I went for a ride boosted alittle, came back my vac was in its current state. Just a little off.

Freakin weird man. I can't seem to shake this vac issue.

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Defgeph

#8

John, at this point I'm not sure what my vac is.

The reason why, I disconnected my Autometer boost guage. Leaving me with the Greddy boost controller reading my vac and boost pressures. The problem is the Greddy reads in some system I'm not familiar with

It reads between -95 to -99. -99 is perfect vac. But it fluxuates between those numbers. Its never solid on one number.

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lagos

#9

when you did your boost leak test, how many psi of air were you able to fill it up to? did you spray everything down with soapy water and watch for bubbles?

there is a very strong chance that the leak is coming from the boost gauge. the nylon hose can crack during installation or your compression fittings might be leaking. another thing to check for is your intake piping, the idle hose that leads all the way to the throttle body, or your distributor oring. those can be tricky to find.

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15PSI - 30MPG - Megasquirt Tuned

Defgeph

#10

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QUOTE(lagos @ May 7, 2007 - 10:46 AM) [snapback]554928[/snapback]

>
when you did your boost leak test, how many psi of air were you able to fill it up to? did you spray everything down with soapy water and watch for bubbles?

20 psi I sprayed everything with soapy water. After I was done I could only hear a very faint hiss from one of the valves on the throttle body. I can't remember the name of this valve at this time, my brain is not working today. I heard that was normal to have some air coming from there.

After I removed the Autometer with the nylon line, the vac was perfect. After a quick ride it fell a few numbers to like -95 -97. I should be at -99.

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Defgeph

#11

Anybody have a vac diagram of a jdm 3sgte ? The celicatech BGB has usdm.

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lagos

#12

have you checked the rubber hose right under the throttle body that goes to the idle valve?
you should also try disconnecting the harness plug that goes to that valve while the car is running, to see if your idle goes up. if it doesn't, then the valve or rubber hose going to it is the problem.

another thing to take a look at is your throttle position sensor. . if thats not plugged in or has been messed with, youll get high idle and that in turn will mess with your vac reading.

This post has been edited by lagos: May 7, 2007 - 10:21 AM

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15PSI - 30MPG - Megasquirt Tuned

Defgeph

#13

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QUOTE(lagos @ May 7, 2007 - 11:16 AM) [snapback]554945[/snapback]

>
have you checked the rubber hose right under the throttle body that goes to the idle valve?

I dont know, I might have. I wish I had a JDM vac diagram so I can point out everything that I changed and things I capped off. I'm just not sure if I changed it with out looking at the engine. The engine is kinda far away right now.

I know I changed one fat hose under the TB that connects to the vac pipe. There is only three hoses on the bottom of the TB two for coolant and one for vac right ?

Isnt there a way to test it ? The TPS.

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lagos

#14

there are bgb multimeter tests for the tps you can do.

if your ever around my way with your car, you can stop by and ill try to help you figure it out.

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15PSI - 30MPG - Megasquirt Tuned

Defgeph

#15

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QUOTE(lagos @ May 7, 2007 - 11:26 AM) [snapback]554948[/snapback]

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there are bgb multimeter tests for the tps you can do.

if your ever around my way with your car, you can stop by and ill try to help you figure it out.

Organize a meet you lazy mofo.

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x_itchy_b_x

#16

http://opc.mr2oc.com/online_parts_catalog/...sgteVacuum1.gif
Thats what i found, hope that helps ya. its usdm but just pretend the egr system is gone.
that leak you heard is the ISC is normal.

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lagos

#17

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QUOTE(defgeph @ May 7, 2007 - 11:28 AM) [snapback]554949[/snapback]

>
>

QUOTE(lagos @ May 7, 2007 - 11:26 AM) [snapback]554948[/snapback]

>
there are bgb multimeter tests for the tps you can do.

if your ever around my way with your car, you can stop by and ill try to help you figure it out.

Organize a meet you lazy mofo.

Jeff's Idle Problem Meet:

place: my house
Time: whenever
Attending: 1. defgeph

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15PSI - 30MPG - Megasquirt Tuned

Defgeph

#18

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Defgeph

#19

Ok I think I have this right. Some of these things I dont know what they are. They are circled. The ones with red X's are removed and vac source for thos items are capped off as close to the manifold as possible.

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lagos

#20

you charcole canister should not be vented to the atmosphere. it should go back to one of the hard lines that goes to the tank.

the vac valve to the right is actually your tvis system. its on the back of the intake manifold .

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15PSI - 30MPG - Megasquirt Tuned

Defgeph

#21

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QUOTE(lagos @ May 7, 2007 - 11:46 AM) [snapback]554959[/snapback]

>
you charcole canister should not be vented to the atmosphere. it should go back to one of the hard lines that goes to the tank.

the vac valve to the right is actually your tvis system. its on the back of the intake manifold .

Maybe this vented port on the canister is my problem then. The stuff on the back of the manifold is intact. Whats TVS and jet ?

new page

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lagos

#22

i dont know about tvs and jet. jet seems like a filter, and tvs seems to be a valve, but ive never seen them on my car before. might be a usdm specific thing.

if i were you, i would take all the vac lines for the canister off and cap the nipple on the engine to see if it helps. it does sound like it could be the cause of your problems.

This post has been edited by lagos: May 7, 2007 - 11:05 AM

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15PSI - 30MPG - Megasquirt Tuned

Defgeph

#23

I'll give it a shot.

Being that I removed my AC. IIRC I had a plug on the idle up valve, should jump this plug or modify my harness in some way ?
I know mine is not the screw type you have, it was electronic.



Also are there any companies out there that make metal vacuum T's. I don't trust the plastic T's I have anymore.

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lagos

#24

if you dont have ac, then you should just totally remove that valve and cap everything on the motor.

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15PSI - 30MPG - Megasquirt Tuned

x_itchy_b_x

#25

I have all the tvis, tvsv, Power steering, and AC idle up valves, all unplugged both hose and harness ways. no codes or weird running conditions.

I agree with Lagos about the canister. maybe the canister itself is punctured?

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Defgeph

#26

All the AC parts are removed. I'm talking about the wiring to the idle up valve. I was wondering if that needed to be modified because I removed the item it was plugged into to.


Maybe the can has a hole, I believe its the original. I didnt swap over the canister from my clip. I just hope this solves my vac and idling issues.

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lagos

#27

you dont have to do anything with the wiring.

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15PSI - 30MPG - Megasquirt Tuned

brianforster

#28

also i never trust the readings of vacuum on my boost controller, ive seen anywhere from -78 to -99 and every time i check my vac with a boost gauge its always right at 20hg warmed up.

before i did my manifold work (gasket + stud replacement + resurfacing) i got -98/99 every time, then i put it back and got low 90's, now im getting mid to high 80's, sometimes it goes to 96 or so again.. its so inconsistent.

yet every time i bring out the boost gauge i get a 20hg reading

Defgeph

#29

Brian, whats the brand name of this inconsistent boost controller ?

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presure2

#30

jeff the 3rd hose under your TB is your idle control valve hose.
the other 2 are coolant lines, like you said.
guys say when you do the leak test to clamp off that hose.
your boost gauge is mechanical, right?
start the car up, and connect the gauge right in the bay, with a nice short hose and check the readings.

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