1998 Chevrolet Blazer LT
121,989mi 4.3l V6 4x4

I want to light my on fire then roll it down a hill. Unfortunately the hill that it is parked on goes into my garage. I had a coolant leak which turns out to be the lower intake gasket every thing back together all plugs in their respective receptacles, no start. Played with it for at least a couple of days, dad came in for Christmas and helped me get it started, but the timing is off I can rotate the distributor counter clockwise and the engine smoothes out and seems to run correctly. But I don’t see how to adjust it permanently. The code is p1345 from the scanner. Which is ignition timing or misfire. Any suggestions or directions would be greatly appreciated as I have to go back to work tomorrow.

Thanks

Hunter

Hunter,
It appears as though the only engines that can be adjusted manually are the Vin Z engines from 94 and 95.

The Vin w engine is supposed to be automatically adjusted via the onboard computer. It may be that the module that controls the timing is bad and needs to be replaced.

Hope that this helps.
bill

when you do the timing, you're supposed to disconnect the computer controls to the distributor and then get a timing light and set it to top dead center. when that is set just plug the computer back in to the distributor and you're ready to go. just a little tip for the future, mark the position of your rotor before you pull the distributor so it saves you the trouble of re-timing it

With the distributor out I set the #1 cyl. to TDC (which I think tends not to matter as the distributor is slotted) at any rate the only thing that plugs into the distributor is the crank sensor or cam sensor. With regards to timing does this sensor control this?

I'm assuming you have the funky HVS ignition system with the flat distributor cap. I found a pic that might help on your timing issue. This pic shows the alignment of the rotor compared to the base, on #1, TDC..
http://i24.photobucket.com/albums/c17/corning_d3/4.jpg

He has a 98, no way to adjust the distributor as it's a locked distributor... From late 95-current is not adjustable (earlier 95's with the top post mount distributor caps are adjustable though)... So regardless if he disconnects the dist from the VCM, it's not adjustable. Only the computer can adjust timing.

If the computer controls the timing, will the computer self correct or is there a way to adjust the timing through the computer? Its terrible that you could put all this time and effort into solving a problem then discover there is no way to correct it.

If the computer controls the timing, will the computer self correct or is there a way to adjust the timing through the computer? Its terrible that you could put all this time and effort into solving a problem then discover there is no way to correct it.

No, the ECM will do any timing adjustments. Really the only thing that could throw it off badly is a bad knock sensor or a jumped timing chain (rare). That will set a code though. I would look more to cap/plugs/wires or crank sensor or even the cam sensor

If the computer controls the timing, will the computer self correct or is there a way to adjust the timing through the computer? Its terrible that you could put all this time and effort into solving a problem then discover there is no way to correct it.
You may need to disconnect the battery for a while (30minute or so) Let you computer relearn and adjust the timing on it's own. Like rlith said, the computer does the timing correction on those models. If that don't do it, might want to consider checking you electronic control module.
Keep us posted. These guys on here are really knowledgable about these motors.
Southern

ya know all this time I NEVER thought of that disconnecting the battery that is. If the computer controls the timing and the computer is reset it seems to me that this will force the computer to adjust timing. I had a 4x4 problem that wouldn't go away. I beat my head aginst the wall for like a month. I started having weak battery problems thinking it was a cracked plate in the battery I took it out to have it tested turns out that problem was the alarm, but when I reinstalled the battery the 4x4 started working again. Anyway worth a shot.

Thanks

Hunter

rlith... I have a P1345 code which is ignition timing or misfire. How likely that is the timing chain? With the distributor bolt out, I can rotate the cap and it runs smoothly. I am only missing by like 5 degrees. Man there is nothing more I would love than to take my 5/16 socket out, disconnect that battery, go play the severely neglected Xbox for about an hour, hook the battery back up and drive away..... huh.. what.. Oh I am awake now I must have dozed off.

rlith... I have a P1345 code which is ignition timing or misfire. How likely that is the timing chain? With the distributor bolt out, I can rotate the cap and it runs smoothly. I am only missing by like 5 degrees. Man there is nothing more I would love than to take my 5/16 socket out, disconnect that battery, go play the severely neglected Xbox for about an hour, hook the battery back up and drive away..... huh.. what.. Oh I am awake now I must have dozed off.
1000 RPM. Monitor camshaft retard on scan tool. If camshaft retard is
-5 to -17 degrees, go to next step. If camshaft retard is not -5 to -
17 degrees, go to step 6).
5) Raise engine speed to 2000 RPM. Check camshaft retard on
scan tool. If camshaft retard changes more than 2 degrees of previous
reading, go to next step. If camshaft retard does not change more than
2 degrees of previous reading, see DIAGNOSTIC AIDS.
6) Check for proper installation of distributor. Remove
distributor cap and gently attempt to rotate rotor. If rotor turns on
distributor shaft, go to step 8). If rotor does not turn on
distributor shaft, go to next step.
7) Check distributor for proper installation. Repair as
necessary. After repairs, go to step 9). If distributor installation
is okay, see DIAGNOSTIC AIDS.
8) Replace distributor. After replacing distributor, go to
next step.
9) Using scan tool, select DTC, CLEAR INFO. Start and warm
engine to normal operating temperature. Select DTC, SPECIFIC, then
enter this DTC. Operate vehicle within the conditions for setting this
DTC. If scan tool indicates that this test ran and passed, go to next
step. If scan tool does not indicate that this test ran and passed,
repeat step 2).
10) Using scan tool, select CAPTURE INFO, REVIEW INFO. If any
undiagnosed DTCs are displayed, go to applicable DTC test.
Diagnostic Aids
Check for loose CMP sensor, excessive free play in timing
chain and gear assembly, incorrectly installed distributor, loose
rotor or distributor hold-down bolt. An intermittent may be caused by
a poor connection, rubbed-through wire insulation or a broken wire
inside insulation.

rlith... I have a P1345 code which is ignition timing or misfire. How likely that is the timing chain? With the distributor bolt out, I can rotate the cap and it runs smoothly. I am only missing by like 5 degrees. Man there is nothing more I would love than to take my 5/16 socket out, disconnect that battery, go play the severely neglected Xbox for about an hour, hook the battery back up and drive away..... huh.. what.. Oh I am awake now I must have dozed off.
Let me try this again.
DTC P1345: CRANKSHAFT/CAMSHAFT POSITION SENSOR CORRELATION
NOTE: For circuit reference, see appropriate wiring diagram in
L - WIRING DIAGRAMS article.
Circuit Description
This DTC monitors the CKP and CMP signals to determine if
they are synchronized. If both signals are not observed by the VCM
within a specified time, VCM will determine that error has occurred.
DTC will set when engine is running, cam sensor reference pulse is not
detected at correct relative position with crank pulse.
Diagnostic Procedures
1) Perform On-Board Diagnostic (OBD) system check. See ONBOARD
DIAGNOSTIC (OBD) SYSTEM CHECK. After performing OBD system
check, go to next step.
2) Install scan tool. Start engine. Using scan tool, monitor
engine RPM. If engine RPM fluctuates up to twice the expected RPM, go
to next step. If engine RPM does not fluctuate up to twice the
expected RPM, go to step 4).
3) Replace crankshaft position sensor. After replacing
sensor, go to step 9).
4) Install scan tool. Start engine. Raise engine speed to

1000 RPM. Monitor camshaft retard on scan tool. If camshaft retard is
-5 to -17 degrees, go to next step. If camshaft retard is not -5 to -
17 degrees, go to step 6).
5) Raise engine speed to 2000 RPM. Check camshaft retard on
scan tool. If camshaft retard changes more than 2 degrees of previous
reading, go to next step. If camshaft retard does not change more than
2 degrees of previous reading, see DIAGNOSTIC AIDS.
6) Check for proper installation of distributor. Remove
distributor cap and gently attempt to rotate rotor. If rotor turns on
distributor shaft, go to step 8). If rotor does not turn on
distributor shaft, go to next step.
7) Check distributor for proper installation. Repair as
necessary. After repairs, go to step 9). If distributor installation
is okay, see DIAGNOSTIC AIDS.
8) Replace distributor. After replacing distributor, go to
next step.
9) Using scan tool, select DTC, CLEAR INFO. Start and warm
engine to normal operating temperature. Select DTC, SPECIFIC, then
enter this DTC. Operate vehicle within the conditions for setting this
DTC. If scan tool indicates that this test ran and passed, go to next
step. If scan tool does not indicate that this test ran and passed,
repeat step 2).
10) Using scan tool, select CAPTURE INFO, REVIEW INFO. If any
undiagnosed DTCs are displayed, go to applicable DTC test.
Diagnostic Aids
Check for loose CMP sensor, excessive free play in timing
chain and gear assembly, incorrectly installed distributor, loose
rotor or distributor hold-down bolt. An intermittent may be caused by
a poor connection, rubbed-through wire insulation or a broken wire
inside insulation.

Thank you for this. Unfortunately my scan tool is fairly limited. I will try these steps anyway. The scan tool just monitors results right?