P1345 - 1998 Blazer

[dmbrisket 51]

because now his ignition timeing is off by a hair

[MT-2500]

Originally Posted by dmbrisket 51

well mdrush, i dont know what to tell you, except, im having the same exact problem, scanner is telling me -20 degrees cam timeing, i go one tooth foward, and come out with +35 degrees cam timeing, ive got a few hours into mine, incluiding a new delco distributor, 10 attempts to reprogram the cam/crank sencer to no avail.., set the vcu to base and it blinks the 1345 at first 1k rpm signal reached, im running out of choices and options here, but if it will help you any, i fudged up when i had my vcu originally programmed for the v 8 and had the v 6 distributor and reluctor in the truck, that gave me a timing or 24 degrees retarted camshaft timeing...

Dmbrisket 51
Did you get this one set back up right or is the dist still off on camshaft timing?
MT

[dmbrisket 51]

im still off, havn't put any time or effert into it seince

[MT-2500]

Originally Posted by dmbrisket 51

im still off, havn't put any time or effert into it seince

It really needs set right before driving it to much.
That far off will burn up the dist cap/rotor and makes the fire/spark to the plugs a lot hotter than it should be.
Could melt the old pistons down over a period of time.
When you get back on it try sloting the hold down clamp or try a adjustable type dist in it.
Let us know how it goes and.
Good Luck MT

[dmbrisket 51]

the distributors on our trucks controll the individual injectors, the truck thinks the timeing between camshaft and crankshaft is off by 20 degrees... the spark is at the correct time, dead nuts correct, the injectors are fireing a little to early, that is why the adjustable thing is not the best idea, it is just a patch, its hurting the cap by moving it foward...

[MT-2500]

Originally Posted by dmbrisket 51

the distributors on our trucks controll the individual injectors, the truck thinks the timeing between camshaft and crankshaft is off by 20 degrees... the spark is at the correct time, dead nuts correct, the injectors are fireing a little to early, that is why the adjustable thing is not the best idea, it is just a patch, its hurting the cap by moving it foward...

The cam retard setting is to set the dist rotor pointer to fire dead center on the dist cap plug wire terminal.
If it is not centered dead on or within -2 or +2 degrees it will cause the spark to have a extra or wider spark gap from the rotor tip to dist cap plug terminal.
Sometimes the extra wide gap or to much - or + cam retard /the rotor tip not being centered to plug wire terminal will cause strange engine running problems.
Like you said the cam sensor may triger the injector timing.
Does the one you have with the cam retart at 20 degrees run good or run like it should?
MT

[mdrush]

Originally Posted by MT-2500

The cam retard setting is to set the dist rotor pointer to fire dead center on the dist cap plug wire terminal.
If it is not centered dead on or within -2 or +2 degrees it will cause the spark to have a extra or wider spark gap from the rotor tip to dist cap plug terminal.
Sometimes the extra wide gap or to much - or + cam retard /the rotor tip not being centered to plug wire terminal will cause strange engine running problems.
Like you said the cam sensor may triger the injector timing.
Does the one you have with the cam retart at 20 degrees run good or run like it should?
MT

One thing I did notice is moving the distributor brought the rotor directly in line with the 6. Before it was slightly off, I also noticed from the fuel trim readings that on the highway I was get crazy fuel trim reading all of the way up to -25 % ST and I could almost watch the fuel gage move down as I drove....after the dist. correction the fuel trim is better than it has ever been, in the test drive cycle it frequently read 0% and only drifter to between -1 and +2 %. Power and responsiveness is definitely noticeable.

From ALLDATA it seems that the CKP controls the Injectors ???

DESCRIPTION
The Crankshaft Position (CKP) Sensor is located in the front engine cover and is perpendicular to the crankshaft target wheel. The air gap between the sensor and the wheel is preset and not adjustable. The target wheel has four slots 60 degrees apart and is keyed to the crankshaft. As the target wheel rotates, the slots passing by the sensor create a change in the magnetic field of the sensor which results in an induced voltage pulse. One revolution of the crankshaft results in four pulses (4x signal). Based on these pulses, the VCM is able to determine crankshaft position and engine speed. The VCM then activates the fuel injector and provides a spark to the Distributor. The relation between the crankshaft position sensor and the target wheel is crucial. The sensor must be exactly perpendicular to the target wheel with the correct air gap.

OPERATION
The crankshaft position sensor provides the VCM with the crankshaft speed and the crankshaft position. The VCM utilizes this information in order to determine if an engine Misfire is present. The VCM monitors the CKP sensor for a momentary drop in the crankshaft speed in order to determine if a misfire is occurring. When the VCM detects a misfire, a DTC P03OO will set.

CMP

DESCRIPTION
The Camshaft Position (CMP) sensor is located within the distributor. The operation of the CMP sensor is very similar to the Crankshaft Position (CKP) sensor. The CMP sensor will provide one pulse per camshaft revolution (1x signal). This signal will not affect the driveability of the vehicle. The VCM utilizes this signal in conjunction with the crankshaft position in order to determine which cylinder(s) are misfiring.

[MT-2500]

Originally Posted by mdrush

One thing I did notice is moving the distributor brought the rotor directly in line with the 6. Before it was slightly off, I also noticed from the fuel trim readings that on the highway I was get crazy fuel trim reading all of the way up to -25 % ST and I could almost watch the fuel gage move down as I drove....after the dist. correction the fuel trim is better than it has ever been, in the test drive cycle it frequently read 0% and only drifter to between -1 and +2 %. Power and responsiveness is definitely noticeable.

From ALLDATA it seems that the CKP controls the Injectors ???

DESCRIPTION
The Crankshaft Position (CKP) Sensor is located in the front engine cover and is perpendicular to the crankshaft target wheel. The air gap between the sensor and the wheel is preset and not adjustable. The target wheel has four slots 60 degrees apart and is keyed to the crankshaft. As the target wheel rotates, the slots passing by the sensor create a change in the magnetic field of the sensor which results in an induced voltage pulse. One revolution of the crankshaft results in four pulses (4x signal). Based on these pulses, the VCM is able to determine crankshaft position and engine speed. The VCM then activates the fuel injector and provides a spark to the Distributor. The relation between the crankshaft position sensor and the target wheel is crucial. The sensor must be exactly perpendicular to the target wheel with the correct air gap.

OPERATION
The crankshaft position sensor provides the VCM with the crankshaft speed and the crankshaft position. The VCM utilizes this information in order to determine if an engine Misfire is present. The VCM monitors the CKP sensor for a momentary drop in the crankshaft speed in order to determine if a misfire is occurring. When the VCM detects a misfire, a DTC P03OO will set.

CMP

DESCRIPTION
The Camshaft Position (CMP) sensor is located within the distributor. The operation of the CMP sensor is very similar to the Crankshaft Position (CKP) sensor. The CMP sensor will provide one pulse per camshaft revolution (1x signal). This signal will not affect the driveability of the vehicle. The VCM utilizes this signal in conjunction with the crankshaft position in order to determine which cylinder(s) are misfiring.

Good info Mdrush

They do run a lot better with the cam retart set right for sure.
MT

[mdrush]

Originally Posted by MT-2500

The cam retard setting is to set the dist rotor pointer to fire dead center on the dist cap plug wire terminal.
If it is not centered dead on or within -2 or +2 degrees it will cause the spark to have a extra or wider spark gap from the rotor tip to dist cap plug terminal.
Sometimes the extra wide gap or to much - or + cam retard /the rotor tip not being centered to plug wire terminal will cause strange engine running problems.
Like you said the cam sensor may triger the injector timing.
Does the one you have with the cam retart at 20 degrees run good or run like it should?
MT

One thing I did notice is moving the distributor brought the rotor directly in line with the 6. Before it was slightly off, I also noticed from the fuel trim readings that on the highway I was get crazy fuel trim reading all of the way up to -25 % ST and I could almost watch the fuel gage move down as I drove....after the dist. correction the fuel trim is better than it has ever been, in the test drive cycle it frequently read 0% and only drifter to between -1 and +2 %. Power and responsiveness is definitely noticeable.

From ALLDATA it seems that the CKP controls the Injectors ???

DESCRIPTION
The Crankshaft Position (CKP) Sensor is located in the front engine cover and is perpendicular to the crankshaft target wheel. The air gap between the sensor and the wheel is preset and not adjustable. The target wheel has four slots 60 degrees apart and is keyed to the crankshaft. As the target wheel rotates, the slots passing by the sensor create a change in the magnetic field of the sensor which results in an induced voltage pulse. One revolution of the crankshaft results in four pulses (4x signal). Based on these pulses, the VCM is able to determine crankshaft position and engine speed. The VCM then activates the fuel injector and provides a spark to the Distributor. The relation between the crankshaft position sensor and the target wheel is crucial. The sensor must be exactly perpendicular to the target wheel with the correct air gap.

OPERATION
The crankshaft position sensor provides the VCM with the crankshaft speed and the crankshaft position. The VCM utilizes this information in order to determine if an engine Misfire is present. The VCM monitors the CKP sensor for a momentary drop in the crankshaft speed in order to determine if a misfire is occurring. When the VCM detects a misfire, a DTC P03OO will set.

CMP

DESCRIPTION
The Camshaft Position (CMP) sensor is located within the distributor. The operation of the CMP sensor is very similar to the Crankshaft Position (CKP) sensor. The CMP sensor will provide one pulse per camshaft revolution (1x signal). This signal will not affect the driveability of the vehicle. The VCM utilizes this signal in conjunction with the crankshaft position in order to determine which cylinder(s) are misfiring.

[dmbrisket 51]

Originally Posted by MT-2500

The cam retard setting is to set the dist rotor pointer to fire dead center on the dist cap plug wire terminal.
If it is not centered dead on or within -2 or +2 degrees it will cause the spark to have a extra or wider spark gap from the rotor tip to dist cap plug terminal.
Sometimes the extra wide gap or to much - or + cam retard /the rotor tip not being centered to plug wire terminal will cause strange engine running problems.
Like you said the cam sensor may triger the injector timing.
Does the one you have with the cam retart at 20 degrees run good or run like it should?
MT

it is a slight dog, but im not sure if i want to blame that on the transmission or the moter (moter) i must have my understanding wrong, i thought the timeing was permenet, and moving the distributor corrected the fuel time, but messed up the ignitions timeing... i may have to try the adjustable method... and yes the roter should line directly up with the 6

[BlazerLT]

Just remember to drop the oil out of it at 1000miles and replace the oil and filter.

This will allow all the filings and left over crap from the engine build to be removed.

[MT-2500]

Originally Posted by dmbrisket 51

it is a slight dog, but im not sure if i want to blame that on the transmission or the moter (moter) i must have my understanding wrong, i thought the timeing was permenet, and moving the distributor corrected the fuel time, but messed up the ignitions timeing... i may have to try the adjustable method... and yes the roter should line directly up with the 6

10-4 Dmbrisket
Moving the dist does not change the timing.
The base timing is set off of the crankshaft sensor.
But getting the cam retartd/dist set right doesseam to make them run better.
Good Luck with it and let us know how it goes..
MT