Idle is a little weak...
11-25-05, 06:47 PM
#1
We are the D
Thread Starter
Join Date: Nov 2005
Location: Indianapolis
Posts: 492
Likes: 0
Received 0 Likes
on
0 Posts
Idle is a little weak...
The idle on my t2 is alittle iffy... It runs beautifully at over 2000 rpms, but when im sitting at a light, it phases... it like runs okay, then the idle drops to about 100-400 rpms, then it goes back to normal idle, then it drops again. I was wondering if it's a fuel injector problem? Or maybe a vacuum system problem? Any help would be appreciated. Thanks
11-27-05, 01:31 AM
#5
Newbie
Join Date: Jun 2004
Location: Richardson, TX
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
For Rolling Idle issues - suspect there is a vacuum leak
"when im sitting at a light, it phases"
I assume you are describing engine RPM's that cycle or in other word are rolling from low to high. My daughter's 87 RX7 GXL was doing this for a couple months. Today I had time to get after - and correct. The writings below are what I did. A prior post here suggesting to check for vacuum leaks first is good advice.
1. Just because vac lines 'look' secure does not mean that they are not leaking some. If your hoses are hard and brittle from age, they may very well be leaking. I literally had to cut some off with an Xacto knife to pull them completely free.
2. I replaced the following lines today:
a) Switching Solenoid Valve (the grey one) - Short 4-5" loop that plugs into the hard line.
The Switching Solenoid Valve hard-line routes toward the firewall and curves under the dynamic chamber to exit on the other side where another hose then connects to the Port Air Solenoid valve nipple. This is the leftmost nipple of two that you will see. I replaced this hose.
b) Relief Solenoid Valve (the Blue one) - another Short 4-5" loop that plugs into a hard line.
The Relief Solenoid Valve hard-line routes toward the firewall and curves under the dynamic chamber to exit on the other side where another rubber hose then connects to the Air Control valve nipple. This is the rightmost nipple of two that you will see. I replaced this hose.
When I had completed A and B - my rolling RPM at idle symptoms were gone but the idle was higher than Factory spec (between 725-775 RPM)
3) Idle Adjustment
a) Checked and adjusted the throttle position sensor. This can be done using a test light or a digital volt meter. At the Green "Check Connector" (Near passenger side front corner) Connect light or digital meter across two of the three pins (one is 12V and the other will read near 0V)
If using a light - Screw the throttle Position sensor screw (counter clockwise) until the light goes out. Then, turn clockwise until the light starts to come on.
If using a digital volt meter - Screw the throttle Position sensor screw (counter clockwise) until the voltage reads near zero. Then, turn clockwise until the voltage reads ~12V.
Take some RTV and seal that screw so it cannot easily come out of adjustment.
4) Idle Speed Adjustment
a) One the driver side you will find another Green Connector with two pins - the "Initial Set Coupler". You will want a jumper between the two pins for this step.
b) Take a blade screw driver and adjust the idle speed adjustment screw that is on top of the throttle body. Screwing in clockwise will lower engine RPM. Again - I suggest taking some RTV and sealing that screw to keep it from 'adjusting itself'.
c) Unhook the "Initial Set Coupler" jumper
All of above should be done with engine hot.
If you are unable to get rid of the rolling idle issue (if steps 1 and 2 do not work), I think doing steps 3 and 4 will be useless to pusue as part of a solution.
Good luck
I assume you are describing engine RPM's that cycle or in other word are rolling from low to high. My daughter's 87 RX7 GXL was doing this for a couple months. Today I had time to get after - and correct. The writings below are what I did. A prior post here suggesting to check for vacuum leaks first is good advice.
1. Just because vac lines 'look' secure does not mean that they are not leaking some. If your hoses are hard and brittle from age, they may very well be leaking. I literally had to cut some off with an Xacto knife to pull them completely free.
2. I replaced the following lines today:
a) Switching Solenoid Valve (the grey one) - Short 4-5" loop that plugs into the hard line.
The Switching Solenoid Valve hard-line routes toward the firewall and curves under the dynamic chamber to exit on the other side where another hose then connects to the Port Air Solenoid valve nipple. This is the leftmost nipple of two that you will see. I replaced this hose.
b) Relief Solenoid Valve (the Blue one) - another Short 4-5" loop that plugs into a hard line.
The Relief Solenoid Valve hard-line routes toward the firewall and curves under the dynamic chamber to exit on the other side where another rubber hose then connects to the Air Control valve nipple. This is the rightmost nipple of two that you will see. I replaced this hose.
When I had completed A and B - my rolling RPM at idle symptoms were gone but the idle was higher than Factory spec (between 725-775 RPM)
3) Idle Adjustment
a) Checked and adjusted the throttle position sensor. This can be done using a test light or a digital volt meter. At the Green "Check Connector" (Near passenger side front corner) Connect light or digital meter across two of the three pins (one is 12V and the other will read near 0V)
If using a light - Screw the throttle Position sensor screw (counter clockwise) until the light goes out. Then, turn clockwise until the light starts to come on.
If using a digital volt meter - Screw the throttle Position sensor screw (counter clockwise) until the voltage reads near zero. Then, turn clockwise until the voltage reads ~12V.
Take some RTV and seal that screw so it cannot easily come out of adjustment.
4) Idle Speed Adjustment
a) One the driver side you will find another Green Connector with two pins - the "Initial Set Coupler". You will want a jumper between the two pins for this step.
b) Take a blade screw driver and adjust the idle speed adjustment screw that is on top of the throttle body. Screwing in clockwise will lower engine RPM. Again - I suggest taking some RTV and sealing that screw to keep it from 'adjusting itself'.
c) Unhook the "Initial Set Coupler" jumper
All of above should be done with engine hot.
If you are unable to get rid of the rolling idle issue (if steps 1 and 2 do not work), I think doing steps 3 and 4 will be useless to pusue as part of a solution.
Good luck
Thread
Thread Starter
Forum
Replies
Last Post
LongDuck
1st Generation Specific (1979-1985)
12
10-07-15 08:12 PM
