Calling all 95 Blazer and S10 4.3 vortec owners that also have a scan tool
#1
08-21-2009, 01:53 AM
Calling all 95 Blazer and S10 4.3 vortec owners that also have a scan tool
does anyone out there have a good running 95 blazer or S10 with a vortec 4.3 "W" engine and have a scan tool to check to see if there timing while idling is jumping around? my timing is jumping around all over the place in the negative area on my 95 S10 4.3 and i need to know if this is normal ? i also have anasty misfire but the engine light is off and i dont have any codes...please help
#6
08-29-2009, 12:32 PM
This may be a difficult thing for 95 owners... There were 3 different ECU/PCM setups for this year making it quite difficult to get a scan tool that works.
As far as timing on other 4.3L equipped years, at idle, it is fairly normal for the timing to jump around a bit. It is controlled by the PCM.
As far as timing on other 4.3L equipped years, at idle, it is fairly normal for the timing to jump around a bit. It is controlled by the PCM.
#7
08-30-2009, 12:39 PM
it says OBD 1 Certified on the emissions sticker under the hood....my intial timing jumps around all over the palce in the negative zone when hooked up to a scanner. it shows -8, -34, -2, -24, 0, -18, just all over the place. we hooked up the same scanner to a 2001 blazer and it was steady within 1 -2 degrees of movement only... in my opinion it shouldnt dance around... but im not sure...
#8
08-31-2009, 07:32 AM
Without the extent of the "jumping around" being defined, it is difficult to say if it is normal or not. I have seen perfectly running vehicles at a hot idle have a +/- 5* swing which to some may seem excessive. It all depends on the operating conditions. I do agree that your swing is excessive.
Just to bring this into one of your threads instead of having it get lost in a 5 month old thread.
Yes, your distributor may have a magnet in it that is part of the pickup coil assembly. It is possible that is the problem with your distributor.
is it true that the distributor shaft itself is a magnet? i read this, but is it true for 1995 CPI Vortec "W" engines with the plastic horizontal distributor? or not?
The magnet, or more properly the reluctor, on the distributor shaft has 3, 4, 5, 6, 8 or 12 "points" on it depending on the number of cylinders the engine has. There is also a sensor, called a pickup, which senses the magnetic field of the point as it passes triggering the spark for the spark plugs. The distance between the point and pickup is usually only 0.006". The reluctor is round and the inside is one pole and the outside is the opposite pole. One is North and the other is South. This gives the reluctor a specific magnetic field.
When there is a crack in the reluctor, one side of the crack becomes North and the other side of the crack becomes South. This changes the magnetic field and confuses the pickup because it's looking for one type of magnetic field and is getting one totally different. This change causes some of the points to be stronger and others weaker resulting in loss of signal and engine misfires.
On some distributors, the reluctor is replaceable separately. On others, you need to replace the whole distributor.
The magnet, or more properly the reluctor, on the distributor shaft has 3, 4, 5, 6, 8 or 12 "points" on it depending on the number of cylinders the engine has. There is also a sensor, called a pickup, which senses the magnetic field of the point as it passes triggering the spark for the spark plugs. The distance between the point and pickup is usually only 0.006". The reluctor is round and the inside is one pole and the outside is the opposite pole. One is North and the other is South. This gives the reluctor a specific magnetic field.
When there is a crack in the reluctor, one side of the crack becomes North and the other side of the crack becomes South. This changes the magnetic field and confuses the pickup because it's looking for one type of magnetic field and is getting one totally different. This change causes some of the points to be stronger and others weaker resulting in loss of signal and engine misfires.
On some distributors, the reluctor is replaceable separately. On others, you need to replace the whole distributor.
Yes, your distributor may have a magnet in it that is part of the pickup coil assembly. It is possible that is the problem with your distributor.
#9
09-01-2009, 10:31 AM
yes i agree too that my timing swing is excess.
How did you confirm that my 1995 distributor shaft has a magnet in it? i want to double check or test that it is one there for sure because i did not know or was not sure if my distributor had a magnet in the center shaft. and i researched the distributors and the 1994 and older dist. deffantly have the magnet in there and are a metal housing type and pointers in it. but my 1995 looks totally different inside and is plastic without any pointers in it. it just has a round black reluctor that is pressed on a shaft. also 1995 dist. is a 1 year only (has a non adjustable collar arm that locates on a pin on the intake) and then 1996 and up are the same(and do not have this locating pin arm). you can see the pictures of the dist. at autozones website. mine is cardone part number 30-1636 and the 96 and newer is 30-1639. the 1994 and older is cardone part# 30-1635. you can see the pointers on the 94 and older from the picture they have. also can magnets rust? only because if you look at my dist. reluctor, you will notice in the center that the center shaft that is showing has rust on it. but this is just the top of the shaft that has the rust. i deeply appreciate any insight on this. i would like to test and see where these magnets exactly are on my dist. im planning on replacing the entire dist. too maybe this week but still would like to find out about the one i have.
thanks much
How did you confirm that my 1995 distributor shaft has a magnet in it? i want to double check or test that it is one there for sure because i did not know or was not sure if my distributor had a magnet in the center shaft. and i researched the distributors and the 1994 and older dist. deffantly have the magnet in there and are a metal housing type and pointers in it. but my 1995 looks totally different inside and is plastic without any pointers in it. it just has a round black reluctor that is pressed on a shaft. also 1995 dist. is a 1 year only (has a non adjustable collar arm that locates on a pin on the intake) and then 1996 and up are the same(and do not have this locating pin arm). you can see the pictures of the dist. at autozones website. mine is cardone part number 30-1636 and the 96 and newer is 30-1639. the 1994 and older is cardone part# 30-1635. you can see the pointers on the 94 and older from the picture they have. also can magnets rust? only because if you look at my dist. reluctor, you will notice in the center that the center shaft that is showing has rust on it. but this is just the top of the shaft that has the rust. i deeply appreciate any insight on this. i would like to test and see where these magnets exactly are on my dist. im planning on replacing the entire dist. too maybe this week but still would like to find out about the one i have.
thanks much
#10
09-01-2009, 01:17 PM
There were two different distributors offered in 95 depending on which ECU/PCM setup you have. True OBD1 setups will have the pickup coil which has a magnetic outer ring. The OBD1.5 and OBD2 setups will not have a magnet.
If your distributor cannot be rotated, but rather has a fixed hold down tab, then you do not have a magnetic pick up. This is replaced with the cam position sensor which is a hall effect sensor and has the metal reluctor ring off of the bottom of the rotor mounting pad.
When I get some free time, I can take apart the distributor on my bench that is from a 96 Astro which should be the same as the OBD1.5 & OBD2 1995 models.
If your distributor cannot be rotated, but rather has a fixed hold down tab, then you do not have a magnetic pick up. This is replaced with the cam position sensor which is a hall effect sensor and has the metal reluctor ring off of the bottom of the rotor mounting pad.
When I get some free time, I can take apart the distributor on my bench that is from a 96 Astro which should be the same as the OBD1.5 & OBD2 1995 models.