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Hello All. I posted about high idle issues a couple months ago and got responses. For some reason I can't find the thread or I'd continue. I found the other one about a dipstick tube, but that doesnt help. The idle issue just doesnt show up. Sorry if this sounds repeat, but it isn't.

Vacuum lines all replaced. No codes. I hear hissing from around the lower area driver's side. If I pinch off the PCV line to the intake manifold, Its stopped. By the way idle works better too. More on that. If I pull the valve and plug it, same result. Remember, I have to manually set the IAC motor. It workd fine doing it that way for years and passed CA smog no problem.

I can only describe the bizarre engine behavior:

I set the IAC for cold start at 900 rpm. I solved a couple problems so idle rises to 950 when warmed. Wont pass smog. Adjusted IAC for 900 rpm hot idle. She runs great. Drove great. She wanted to GO!. Parked it and checked RPM with the meter. 1000 rpm. Shut off and restarted. 600 rpm. Then up to 850. Readjust AIS motor to 900. Drives Great. Park, shut down, restart hot again, 1050 rpm.

Oh, and there's more. On hot restart, after a couple minutes if idle is climbing over 950, I hear one of the vacuum solenoids across the engine compartment from where I am (because it only happens when I'm across the car and didn't get a chance to feel for which solenoid it was) clicks and idle lowers to 900. Drives great. Shut down. Restart barely runs. 600, 500 rpm and I have to hold the pedal down until it sets itself to idle on its own. This only happens some times, not all.

Something new: The PCV valve is rattling on and off at idle. Its loud. It hasn't done that before, But I closed a leak recently. I replaced the PCV valve a couple years ago, but the car hasn't run. See above. I replaced the vacuum lines (with PCV tubing) at last posting, about 4 months ago. Thinking of replacing the valve again. Maybe the intake filter in the air box is clogged? I'll check it in the morning on a complete cold start test.

This was a great runner up until 4 years ago when this all started. I commuted 54 mi each direction daily and it ran great. I've thought of getting rid of it. The wife: yes The Wife, says Keep it. Get it running again. I'm stuck.

What could be the issue here? Any likely suspects?

Any help would be appreciated.

Thank you
 

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Hello All. I posted about high idle issues a couple months ago and got responses. For some reason I can't find the thread or I'd continue. I found the other one about a dipstick tube, but that doesnt help. The idle issue just doesnt show up. Sorry if this sounds repeat, but it isn't.

Vacuum lines all replaced. No codes. I hear hissing from around the lower area driver's side. If I pinch off the PCV line to the intake manifold, Its stopped. By the way idle works better too. More on that. If I pull the valve and plug it, same result. Remember, I have to manually set the IAC motor. It workd fine doing it that way for years and passed CA smog no problem.

I can only describe the bizarre engine behavior:

I set the IAC for cold start at 900 rpm. I solved a couple problems so idle rises to 950 when warmed. Wont pass smog. Adjusted IAC for 900 rpm hot idle. She runs great. Drove great. She wanted to GO!. Parked it and checked RPM with the meter. 1000 rpm. Shut off and restarted. 600 rpm. Then up to 850. Readjust AIS motor to 900. Drives Great. Park, shut down, restart hot again, 1050 rpm.

Oh, and there's more. On hot restart, after a couple minutes if idle is climbing over 950, I hear one of the vacuum solenoids across the engine compartment from where I am (because it only happens when I'm across the car and didn't get a chance to feel for which solenoid it was) clicks and idle lowers to 900. Drives great. Shut down. Restart barely runs. 600, 500 rpm and I have to hold the pedal down until it sets itself to idle on its own. This only happens some times, not all.

Something new: The PCV valve is rattling on and off at idle. Its loud. It hasn't done that before, But I closed a leak recently. I replaced the PCV valve a couple years ago, but the car hasn't run. See above. I replaced the vacuum lines (with PCV tubing) at last posting, about 4 months ago. Thinking of replacing the valve again. Maybe the intake filter in the air box is clogged? I'll check it in the morning on a complete cold start test.

This was a great runner up until 4 years ago when this all started. I commuted 54 mi each direction daily and it ran great. I've thought of getting rid of it. The wife: yes The Wife, says Keep it. Get it running again. I'm stuck.

What could be the issue here? Any likely suspects?

Any help would be appreciated.

Thank you
What year/engine? Codes? Timing? Check for vac leaks with brake parts cleaner?
 

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I would start by verify base idle is correct and TPS voltage is below .90 volts at closed throttle.
 

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Hello All. I posted about high idle issues a couple months ago and got responses. For some reason I can't find the thread or I'd continue. I found the other one about a dipstick tube, but that doesnt help. The idle issue just doesnt show up. Sorry if this sounds repeat, but it isn't.

Vacuum lines all replaced. No codes. I hear hissing from around the lower area driver's side. If I pinch off the PCV line to the intake manifold, Its stopped. By the way idle works better too. More on that. If I pull the valve and plug it, same result. Remember, I have to manually set the IAC motor. It workd fine doing it that way for years and passed CA smog no problem.

I can only describe the bizarre engine behavior:

I set the IAC for cold start at 900 rpm. I solved a couple problems so idle rises to 950 when warmed. Wont pass smog. Adjusted IAC for 900 rpm hot idle. She runs great. Drove great. She wanted to GO!. Parked it and checked RPM with the meter. 1000 rpm. Shut off and restarted. 600 rpm. Then up to 850. Readjust AIS motor to 900. Drives Great. Park, shut down, restart hot again, 1050 rpm.

Oh, and there's more. On hot restart, after a couple minutes if idle is climbing over 950, I hear one of the vacuum solenoids across the engine compartment from where I am (because it only happens when I'm across the car and didn't get a chance to feel for which solenoid it was) clicks and idle lowers to 900. Drives great. Shut down. Restart barely runs. 600, 500 rpm and I have to hold the pedal down until it sets itself to idle on its own. This only happens some times, not all.

Something new: The PCV valve is rattling on and off at idle. Its loud. It hasn't done that before, But I closed a leak recently. I replaced the PCV valve a couple years ago, but the car hasn't run. See above. I replaced the vacuum lines (with PCV tubing) at last posting, about 4 months ago. Thinking of replacing the valve again. Maybe the intake filter in the air box is clogged? I'll check it in the morning on a complete cold start test.

This was a great runner up until 4 years ago when this all started. I commuted 54 mi each direction daily and it ran great. I've thought of getting rid of it. The wife: yes The Wife, says Keep it. Get it running again. I'm stuck.

What could be the issue here? Any likely suspects?

Any help would be appreciated.

Thank you
Check the engine for excessive movement due to worn or broken engine mounts. I had a problem with my '89 LeBaron throttle sticking and the cause was a broken front mount and the throttle cables not being attached securely near the TB, caused by excessive rotation of the engine.
 

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Discussion Starter · #5 ·
Hello All, and Thank you for the responses. I'll try to cover the questions and I still have a couple.

Info on the car as requested: 1987 Shelby Dodge Charger, 2.2 T-1.

Motor munts are new. When I got the car I found all three were busted. I replaced them and drove it all the time afterwards.

I did the base idle procedure. Base idle went right to 900. Thats the spec. I need it there all the time and consistent to get past Ca Smog Test Only. Here in Ca, they pay to junk these things when they don't pass smog. Nope! I need to get this resolved.

Here's where I'm at: I'm thinking its a start up issue. Base idle is at 900. Cold start, it won't run unless I'm on the gas a minute or two. Then it idles about 500, slowly climbing to 780-ish. If I rev it a while, sometimes it gets to 900 and stays. Hot start up is the same except it runs at 500 then slowly over a few minutes (Timed about 5 minutes) gets to either 900 or 850. Sometimes when its at 850, it will go to the correct 900 after taking RPM up to 2k and back.

So at start up hot or cold, it runs like crap. Once hot, idle is not consistent. Sometimes its correct and sometimes it is low. The smog shop wont look it if it runs like that.

I checked the PCV intake and cleaned it. It's fine. PCV valve still rattled until I pinched off the line. It stopped rattling after that. The hissing noise I hear is for sure without a doubt the PCV valve sucking air.

What could be causing this hot and cold start up and inconsistent idle?
 

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Discussion Starter · #7 ·
For TPS voltage check. There are three wires. To which do I place Positive probe and to what do I put ground? For this test, is it another wire or chassis ground?

Thanks
I found the earlier thread on this. Naj, I'll check TPS readings based on what you sent. Orange with Dark brown and the negative goes to the black wire. I think the third is Orange with a lighter color.
 

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TPS Signal - OR/DB
TPS Signal Return - BK/LB

Closed Throttle - below .90 volts and steady
WOT - anything above 3.50 volts
 

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Any updates on this? I'm experiencing similar issues on my 85 Dodge 600 T1 turbo car. I have ran new vacuum lines but trying to diagnose if I have a bad MAP sensor or not. It won't start on its own when cold unless I give it gas. If it does stay running after I give it gas the idles surges up and down. I have cleaned the TB and set base idle as well. Not sure where to go from here.
 

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Any updates on this? I'm experiencing similar issues on my 85 Dodge 600 T1 turbo car. I have ran new vacuum lines but trying to diagnose if I have a bad MAP sensor or not. It won't start on its own when cold unless I give it gas. If it does stay running after I give it gas the idles surges up and down. I have cleaned the TB and set base idle as well. Not sure where to go from here.
Maybe temp sensor? U know you can test each sensor/injector with a multimeter?
 

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Any updates on this? I'm experiencing similar issues on my 85 Dodge 600 T1 turbo car. I have ran new vacuum lines but trying to diagnose if I have a bad MAP sensor or not. It won't start on its own when cold unless I give it gas. If it does stay running after I give it gas the idles surges up and down. I have cleaned the TB and set base idle as well. Not sure where to go from here.
Not starting unless you open the throttle and idles up/down after start still sounds like a vacuum leak or base idle/TPS closed throttle voltage is not correct, it could also be related to other fuel/mechanical issues.

1)Is the idle still erratic with the AIS at 0 steps and disconnected from the system? (Base Idle)

2)Are any fault codes stored in memory?

3)What is engine vacuum reading at a manifold source and at the Map Sensor (You have to "Tee" into the Map Sensor Line to read MAP vacuum, they should read the same, 16"-20" HG @ idle is normal.

4)What is fuel pressure reading?

5)Is Cam/Ignition timing correct?
 

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Not starting unless you open the throttle and idles up/down after start still sounds like a vacuum leak or base idle/TPS closed throttle voltage is not correct, it could also be related to other fuel/mechanical issues.

1)Is the idle still erratic with the AIS at 0 steps and disconnected from the system? (Base Idle)

2)Are any fault codes stored in memory?

3)What is engine vacuum reading at a manifold source and at the Map Sensor (You have to "Tee" into the Map Sensor Line to read MAP vacuum, they should read the same, 16"-20" HG @ idle is normal.

4)What is fuel pressure reading?

5)Is Cam/Ignition timing correct?

I'll check 3,4, and 5 tonight but the idle is steady(although slightly high with brake booster vacuum unplugged) with the AIS and TPS unplugged. They both go to the same connector so I can't unplug one at a time unless I add in a secondary connector for one of them. Is it okay to have TPS unplugged as well when setting base idle?

It doesn't appear to have any codes popping up quickly when starting up and idling for a bit. I need to drive it some tonight to see if any arise. I have cleared them out recently due to running the base idle setting procedure and setting codes related to that.
 

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You cannot have the TPS unplugged, this will put the car in "Failure/Limp In Mode", the Power Loss/Check Engine Lamp will illuminate, a Code 24 (TPS voltage high/low) will be set and the car will run on a fixed "Limp In" mode program.

You would have to remove the wires for the AIS from the connector once you know the AIS is fully seated and closed, cut the wiring and use quick connects or use a scanner to obtain Minimum Idle RPM.
 

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You cannot have the TPS unplugged, this will put the car in "Failure/Limp In Mode", the Power Loss/Check Engine Lamp will illuminate, a Code 24 (TPS voltage high/low) will be set and the car will run on a fixed "Limp In" mode program.

You would have to remove the wires for the AIS from the connector once you know the AIS is fully seated and closed, cut the wiring and use quick connects or use a scanner to obtain Minimum Idle RPM.
Just rechecked the base idle by putting in some quick connects in the ais circuit. Made no difference in idle. My manifold vacc at idle is reading at about 10HG and just below that when I insert a T into the line going to the map sensor.
I was going to next check the timing as I can’t find any kind of vacuum leak anywhere when carefully using a can of carb cleaner to spray around the vacuum lines and connections. Sound like a good plan?
 

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Just rechecked the base idle by putting in some quick connects in the ais circuit. Made no difference in idle. My manifold vacc at idle is reading at about 10HG and just below that when I insert a T into the line going to the map sensor.
I was going to next check the timing as I can’t find any kind of vacuum leak anywhere when carefully using a can of carb cleaner to spray around the vacuum lines and connections. Sound like a good plan?
10hg is way too low I thought the 15 I got from my 89 2.2 Tbi was bad. My 88 T1 2.2 gets 19-20. I think your timing belt is off a tooth or you are using the wrong timing mark for the ign timing. My 86 T1 gets 10 sometimes in gear then jumps back to 18 I think it's the injectors or O rings Because it only does it once in a while or if it's been sitting a long time I start the engine surges like crazy then snaps out of it.

This 2.5 T1 gets 19HG and the cylinder walls were badly scratched but it actually runs good and doesn't smoke...
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Ok I have been trying to do all this without taking off all the accessories but I guess I'll have to start tearing it all off to see the crank pulley. I'm working on borrowing a fuel pressure gauge so I can test that as well. My question remains though, do I need to fully remove the distributer to verify the oil pump timing?
 

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To answer/respond to some of your questions/comments...
1)"do I need to fully remove the distributer to verify the oil pump timing?"
It is not oil pump timing, the oil pump drives the distributor and if the marks between the crank sprocket and intermediate shaft are not correct then the rotor will not be pointing directly to #1 cylinder on the distributor cap.
This happens a lot and is not an issue if you have enough distributor adjustment to properly set ignition timing, the distributor may also be fully turned one way or another rather than almost parallel to the block which is more aesthetics than anything else.
2)"the idle is steady(although slightly high with brake booster vacuum unplugged"
Idle speed should increase when you create a large vacuum leak that is central (affects all cylinders equally).
When you create the vacuum leak more air enters the engine, the controller see's this through MAP Sensor voltage, it increases the fuel amount (injector pulse width) for the added air, more air + more fuel = higher idle speed.
With the idle speed higher than normal the engine controller will attempt to lower/bring back in specs the idle speed by closing/extending the AIS gears/pintle.
You never want to disconnect the AIS while it is moving as this may spike the engine controller, you have to wait until it is fully seated and no longer moving, waiting 60 seconds after creating the large vacuum leak is sufficient.
Once the AIS gets to 0 steps (fully seated) it is then safe to disconnect.
Before reconnecting shut the engine off.

Now onto current issues...
Your issue assuming this reading is correct is 10" HG, that is EXTREMELY LOW.
The car should barely be running with 10"HG and should be extremely rich due to low vacuum at the MAP Sensor.

Low engine vacuum can be caused by...
1)Worn Rings (Compression Test and Cylinder Leakdown Test)
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2)Vacuum Leak (That includes the Brake Booster, HVAC System and Instrument Cluster if the vehicle has a Boost Gauge)
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3)Cam/Ignition Timing
a)Disconnect and Isolate the - (Negative) Battery Terminal.
b)Remove all 4 spark plugs
c)Bring #1 cylinder to TDC on a Compression Stroke
d)Align the timing mark on the flywheel with "0" on the timing mark indicator.
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e)The slot in the cam sprocket should be at 12 o'clock center with the cylinder head.
The head is on an angle so it will not be 12-6.
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f)The distributor rotor should be pointing towards #1 cylinder on the distributor cap.
The oil pump slot will be parallel to the block if the intermediate shaft is properly aligned with the mark on the crank sprocket.
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g)If any are not properly aligned you will need to remove the belt and realign the sprockets.
h)Once that is done rotate the crank 2 revolutions clockwise by hand and bring #1 back to TDC and the timing mark on 0.
i)Recheck mark alignment and belt tension, repeat as needed.
j)Check and Set Ignition Timing
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4)Restricted Exhaust
a)The car will be hard to start, have little to no power and low engine vacuum.
b)You can actually check exhaust backpressure or you can try removing the O2 sensor and starting the engine, removal of the O2 may relieve the backpressure enough that the car should run slightly better.
To check exhaust backpressure you will need an adapter to screw in where the O2 sensor goes (18mm) with a port to attach your gauge.


Connect your vacuum/pressure gauge to the adapter and start the car. Pressure should be no more than 2 PSI at idle and 2000 no load RPM's.
 
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