what can cause a timing retard??
Thread Starter
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Beginning Member
Joined: Dec 2010
Posts: 32
what can cause a timing retard??
hello again!!
today i just played with my cheap OBDII Scanner and my new Palmer ScanXL Software with de GM Addon.
and the CMP RETARD it's (-10). so how can this affect to my little Blazer ZR2 2001 4.3 ??
tomorrow i'll put it to Zero. with the help of my dad.
this thing can reduce my fuel economy?
can cause my 1st Cylinder to misfire?
thank you
today i just played with my cheap OBDII Scanner and my new Palmer ScanXL Software with de GM Addon.
and the CMP RETARD it's (-10). so how can this affect to my little Blazer ZR2 2001 4.3 ??
tomorrow i'll put it to Zero. with the help of my dad.
this thing can reduce my fuel economy?
can cause my 1st Cylinder to misfire?
thank you
Super Member
Joined: Sep 2010
Posts: 1,485
From: Lynnwood WA
Heres a quote from the good Captain..
Not sure what can cause it so hopefully he chimes in. Just curious tho, how are you going to set it to zero?
Not sure what can cause it so hopefully he chimes in. Just curious tho, how are you going to set it to zero?
Senior Member
Joined: Jun 2011
Posts: 640
From: Northern Maine
The distributor can be rotated via play in the hold-down bolt hole, loosen the bolt a little and rotate the shaft until it reaches 0, tighten bolt. done.
Quote Swartlkk:
Once this task has been completed, a scan tool capable of displaying live data, CMP Retard specifically, will need to be used inorder to set the CMP Retard to 0 degrees. The CMP Retard is altered by shifting the distributor in the somewhat oversized hole through the LIM. Even though the hole in the distributor hold down clamp is not slotted and the clamp is fixed to the base of the distributor, there is enough play in the hole through the lower intake manifold to allow for modification of up to 15 degrees if my information is accurate. CMP Retard must be properly set to 0 degrees to A) accurately time the spark for each cylinder by giving the widest available advance/retard window & B) to properly align the distributor drive gear on the cam. Failure to do so could result in premature distributor drive gear wear.
Quote Swartlkk:
Once this task has been completed, a scan tool capable of displaying live data, CMP Retard specifically, will need to be used inorder to set the CMP Retard to 0 degrees. The CMP Retard is altered by shifting the distributor in the somewhat oversized hole through the LIM. Even though the hole in the distributor hold down clamp is not slotted and the clamp is fixed to the base of the distributor, there is enough play in the hole through the lower intake manifold to allow for modification of up to 15 degrees if my information is accurate. CMP Retard must be properly set to 0 degrees to A) accurately time the spark for each cylinder by giving the widest available advance/retard window & B) to properly align the distributor drive gear on the cam. Failure to do so could result in premature distributor drive gear wear.
Last edited by coolasice; Oct 22, 2012 at 06:14 AM.
Junior Member
Joined: Apr 2012
Posts: 368
From: Vancouver, BC, Canada
hello again!!
today i just played with my cheap OBDII Scanner and my new Palmer ScanXL Software with de GM Addon.
and the CMP RETARD it's (-10). so how can this affect to my little Blazer ZR2 2001 4.3 ??
tomorrow i'll put it to Zero. with the help of my dad.
this thing can reduce my fuel economy?
can cause my 1st Cylinder to misfire?
thank you
today i just played with my cheap OBDII Scanner and my new Palmer ScanXL Software with de GM Addon.
and the CMP RETARD it's (-10). so how can this affect to my little Blazer ZR2 2001 4.3 ??
tomorrow i'll put it to Zero. with the help of my dad.
this thing can reduce my fuel economy?
can cause my 1st Cylinder to misfire?
thank you
You will need to rotate the distributor counter clockwise to get it to zero. You will need to check the setting at 1,000 rpm or 2,000 rpm, depending on the year of the engine.
How do you like the Scan XL software? Fun isn't it? I have the same software
Thread Starter
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Beginning Member
Joined: Dec 2010
Posts: 32
Yes can cause crossfire in the cap. As the distributor gear wears the cam retard goes out.
You will need to rotate the distributor counter clockwise to get it to zero. You will need to check the setting at 1,000 rpm or 2,000 rpm, depending on the year of the engine.
How do you like the Scan XL software? Fun isn't it? I have the same software
You will need to rotate the distributor counter clockwise to get it to zero. You will need to check the setting at 1,000 rpm or 2,000 rpm, depending on the year of the engine.
How do you like the Scan XL software? Fun isn't it? I have the same software
Yes its really fun and very useful tool. When i purchased my generic scan tool ,i tested with a bunch of softwares and some where compatible and other not.
But with this software im happy to watch all the values. Im gonna save big because in shops doing this kind of thing cost too much.damn mechanics jeje.
And yes i'll try to move the distributor to set it to zero. This is greAt because when my mechanic changed the water gaskets under the manifold and other stuff ,he pull the dist and i always have the doubt about the timing.
I was getting some misfire code and a bad furl consumption, i hope...really hope to get a solution with the thing of the time.
Thanks guys.
Thread Starter
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Beginning Member
Joined: Dec 2010
Posts: 32
The distributor can be rotated via play in the hold-down bolt hole, loosen the bolt a little and rotate the shaft until it reaches 0, tighten bolt. done.
Quote Swartlkk:
Once this task has been completed, a scan tool capable of displaying live data, CMP Retard specifically, will need to be used inorder to set the CMP Retard to 0 degrees. The CMP Retard is altered by shifting the distributor in the somewhat oversized hole through the LIM. Even though the hole in the distributor hold down clamp is not slotted and the clamp is fixed to the base of the distributor, there is enough play in the hole through the lower intake manifold to allow for modification of up to 15 degrees if my information is accurate. CMP Retard must be properly set to 0 degrees to A) accurately time the spark for each cylinder by giving the widest available advance/retard window & B) to properly align the distributor drive gear on the cam. Failure to do so could result in premature distributor drive gear wear.
Quote Swartlkk:
Once this task has been completed, a scan tool capable of displaying live data, CMP Retard specifically, will need to be used inorder to set the CMP Retard to 0 degrees. The CMP Retard is altered by shifting the distributor in the somewhat oversized hole through the LIM. Even though the hole in the distributor hold down clamp is not slotted and the clamp is fixed to the base of the distributor, there is enough play in the hole through the lower intake manifold to allow for modification of up to 15 degrees if my information is accurate. CMP Retard must be properly set to 0 degrees to A) accurately time the spark for each cylinder by giving the widest available advance/retard window & B) to properly align the distributor drive gear on the cam. Failure to do so could result in premature distributor drive gear wear.
what can i do in this case??
thanks
Moderator
Joined: Mar 2009
Posts: 8,453
From: Belleville, Michigan
Cmp 101
The "slop" between the distributor housing and the hole in the intake manifold allows for ~15 degrees total adjustment, (~7 degrees in each direction). A worn distributor drive gear and a stretched timing chain will both cause camshaft retard to change. The most common reason is when the distributor is removed, camshaft retard adjustment is gone. Lower intake manifold gasket replacement requires distributor removal. A good technician will check, (and adjust if necessary) camshaft retard before he returns the vehicle to its owner. The purpose of the adjustment is to precisely align the camshaft position sensor, (hence the name) with the camshaft. It also aligns the rotor with the terminals inside the cap to reduce crossfire. If you can't get cam retard to spec, you can remove the OEM hold down bracket and install one of these: Mr Gasket Part No. 1009 - Distributor Clamps
Aligning the gear with the camshaft is not an issue: when camshaft retard is adjusted, the alignment of the gear, is what it is. Data from the camshaft position sensor, along with data from the crankshaft position sensor, is used by the PCM for accurately, (keyword being accurately) detecting and identifying which cylinders are misfiring. If cam retard is off, so is cylinder misfire data on the scan tool, (P0301 through P0306). The CMP sensor data is only used for this purpose. You can disconnect it while the engine is running and it will have no affect. On older vehicles, ignition timing was adjusted by rotating the distributor. In a round about kind of way, it affects timing on this engine as well, but in a bad way. When the PCM applies a given amount of advance, the PCM has no way of "knowing" if it's actually applying the correct amount. The PCM has to "assume" camshaft retard is adjusted correctly. If camshaft retard is off -15 degrees, and the PCM applies +15 degrees of advance, you end up with no advance. Tell me THAT won't affect fuel mileage and performance
Aligning the gear with the camshaft is not an issue: when camshaft retard is adjusted, the alignment of the gear, is what it is. Data from the camshaft position sensor, along with data from the crankshaft position sensor, is used by the PCM for accurately, (keyword being accurately) detecting and identifying which cylinders are misfiring. If cam retard is off, so is cylinder misfire data on the scan tool, (P0301 through P0306). The CMP sensor data is only used for this purpose. You can disconnect it while the engine is running and it will have no affect. On older vehicles, ignition timing was adjusted by rotating the distributor. In a round about kind of way, it affects timing on this engine as well, but in a bad way. When the PCM applies a given amount of advance, the PCM has no way of "knowing" if it's actually applying the correct amount. The PCM has to "assume" camshaft retard is adjusted correctly. If camshaft retard is off -15 degrees, and the PCM applies +15 degrees of advance, you end up with no advance. Tell me THAT won't affect fuel mileage and performance
Last edited by Captain Hook; Oct 22, 2012 at 06:42 PM.
