P1345 - 1998 Blazer

For those of you that remember me I was the guy who's engine was fried at a speed lube. Well, engine is now replaced and court case is in process, just filed an action last week.

The engine instalation went well, a reman GM engine from the dealer, new radiator, Water pump, engine mounts, O2 sensors, hoses, Crank sensor, Knock sensor, Cleaned and replaced various fuel injection components etc.

Initial startup was flawless, runs very smooth with lots of power. Then I noticed the check engine light....put it on the scanner and found a code P1345....Cam shaft postion sensor, Crank shaft postion sensor correlation error.

I read though literally 50 online articles dealing wth this code...the guy who installed the engine (a retired mechanic) checked and reinstalled the distributor at least 10 times...made sure that it was properly seated and in the slot. Still produces a P1345 on startup.

After reading it is probably timing related (and a proper scan tool is needed)I took it to a very reputable ASE mechanic in town...he initially tought it was off a tooth and quoted me 45 minutes to "0 it in". After 4 hours and a new distributor we are back at square 1. When I picked it up Friday he told me that he's going to have to call GM on Monday..He says he gets 24 degrees where it is now, moving it one tooth gets him -27 degrees...doesn't make sense to either of us. He even tested a new crank sensor.

From what he found we came up with 3 possible scenarios :

1. ECU is messed up.
2. New engine has an internal problem...cam tolerances etc,
3. We're missing something (most likely scenario)

The engine seems to run fine (smooth idle, acceleration, power) and my scanner finds no misfires.

Any help would be greatly appreciated.....I'm ready to get the engine replacement behind me and focus on my speedlube lawsuit.

sorry to hear about your problem, hear about it atleast once every 6months at work... i had the same problem when i converted, you need to go to the dealership and have them do the re-learn procedure, i got the same exact code when i swaped my 4.3 to a 5.7 and the tech at the dealer who programmed my 4.3 pcm into a 5.7pcm told me i would get a p 1345 and a possible p0300, so my guess is nothing is wrong, just needs to re-learn itselfe

24-27 degrees is a loy off on it.
Is there any way you can slot the hold down clamp by drilling/filling the bolt hole in sideways to get enough turn on the dist to center it up?
Or turn the dist gear on end of dist shaft 180 degrees?
Or even get a 350 dist housing that is made to turn or not square notched on the base of dist.
MT

I have to believe this is not so much a timing issue but a computer issue which dmbrisket 51 mentioned. If it was that far off i can't see it running as good as it does.

I found an article that mentions the CASE learn (crankshaft variation) being required after : engine replacement, harmonic balancer replacement, CS postion sensor replacement etc.

http://www.bsecorp.com/files/techtips/ST9303l.pdf

The article states that the CASE relearn can either be performed by using a scantool or through the GM driving cycle.

I think I'll reset the ECU and try the driving cycle.....failing that, I'll stop by the dealer tomorrow as dmbrisket suggested.

Well....$ 546.00 later and a new GM distributor from the dealer and I still have the P1345.

The dealer told me it could be an internal engine problem with the new engine or it could have been damage caused by to the cam gear by improper installation of the distributor by the guy that installed the new engine.

The engine has a 36 month 100K mile warranty but GM states that if they pull the engine and find a worn CAM gear I'm responsible for the $2800.00 labor charge. After already spending 3000.00 to for the reman engine and installation on this thing I'm stressed and can't afford to pay for another engine install.

I spoke with the retired mechanic who put the new engine in and he can't think of anything that would have caused any damage. The only thing thing he could come up with was the reluctor wheel...he told me it can go in two ways and he's sure he put it in right but it is slightly possible it was backwards.

He told me he'll make it right but before he tears into the engine I'm hoping someone can offer some suggestions.

1. The vehicle runs smooth, even though the timing is retarded 24 degress. Would the truck even run if the reluctor wheel was backwards ?

2. Any other possible scenarios or diagnostics ?

Here's what we've replaced so far.

Reman 4.3 V6 from GM
New GM distributor with Cam sensor
New Crank sensor
New Knock sensor

The dealer told me I can drive it with retarded timing without doing any damage...however I want to get the corrected. If we slot the distributor hold down, we'll void the GM warranty.

Any help would be appreciated.

Well....$ 546.00 later and a new GM distributor from the dealer and I still have the P1345.

The dealer told me it could be an internal engine problem with the new engine or it could have been damage caused by to the cam gear by improper installation of the distributor by the guy that installed the new engine.

The engine has a 36 month 100K mile warranty but GM states that if they pull the engine and find a worn CAM gear I'm responsible for the $2800.00 labor charge. After already spending 3000.00 to for the reman engine and installation on this thing I'm stressed and can't afford to pay for another engine install.

I spoke with the retired mechanic who put the new engine in and he can't think of anything that would have caused any damage. The only thing thing he could come up with was the reluctor wheel...he told me it can go in two ways and he's sure he put it in right but it is slightly possible it was backwards.

He told me he'll make it right but before he tears into the engine I'm hoping someone can offer some suggestions.

1. The vehicle runs smooth, even though the timing is retarded 24 degress. Would the truck even run if the reluctor wheel was backwards ?

2. Any other possible scenarios or diagnostics ?

Here's what we've replaced so far.

Reman 4.3 V6 from GM
New GM distributor with Cam sensor
New Crank sensor
New Knock sensor

The dealer told me I can drive it with retarded timing without doing any damage...however I want to get the corrected. If we slot the distributor hold down, we'll void the GM warranty.

Any help would be appreciated.


Someone is giving you the old run around and feeding you full of bull.
The cam retart needs to be set no more than 2-3 degree off.
Running it tht far off will burn up cap and rotor and cause hoter spark to plugs and may burn a hole in the piston.
If GM can not get it set ask for another engine.
That old crap they are feeding you about improper installation is bull.

If a new dist does not make it come out you have a camshaft crankshaft set up/mix up problem.
Slotting the dist hold down clam has nothing to do with warranty
Take the hold down bolt out of the hold down clamp and see if moving the dist around by hand will bring the cam retard back in to specs.
If it does redo the clamp so you can clamp the dist down in the right spot where cam retard is in specs.

Who is woring on it or trying to get it set?
You or GM or the mechanic that put the engine in?
MT

Basically when he got the engine in (he was doing me a favor $500.00), it started fine and seem to run good....but we had the 1345 code. The guy tries to set the timing by hand (he didn't have the right scanner) 3 times.

Finally I took it to a garage in town and he tried from scratch to zero it in. First he tried to move the distributor a tooth took it from 30 degrees to -30 degrees. After about 3 hours of labor, he put in a NAPA reman distributor and managed to get it set at 24 degress...

I then took it to the dealership where they came up with a damaged cam gear theory..said the Distributor gear looked like it was wearing unevenly...the GM mechanic put a new GM distributor in and still couldn't get it to move past 24 degrees.

Basically when he got the engine in (he was doing me a favor $500.00), it started fine and seem to run good....but we had the 1345 code. The guy tries to set the timing by hand (he didn't have the right scanner) 3 times.

Finally I took it to a garage in town and he tried from scratch to zero it in. First he tried to move the distributor a tooth took it from 30 degrees to -30 degrees. After about 3 hours of labor, he put in a NAPA reman distributor and managed to get it set at 24 degress...

I then took it to the dealership where they came up with a damaged cam gear theory..said the Distributor gear looked like it was wearing unevenly...the GM mechanic put a new GM distributor in and still couldn't get it to move past 24 degrees.

The dealer is jacking you around big time.
Find another dealer or get on his case big time.
If this is a new GM or GM rebuilt tell them to fix it on there dime.
Since they put a new dist in it they have no excuses left.
If they will not fix it parts and labor on there dime then call the 800 customer service no in your service manual or get out your warranty papers and look for a 800 no in there to call.
MT

There is a simple test on seting the dist.
Remove dist cap and on the top of the dist there will be a 6 and a 8 stamped on it On a V6 you point the rotor dead on with the no 6 and on a V8 you point the rotor dead on with the 8.
That is with no one cylinder on TDC compression stroke.
Check that out and if it comes out.
You have a crank sensor mark or a messed up VCM/computeer.
Hit me with a private e mail and i will post you a PDF on it.
Also No one plug wire position on bottom of the dist cap will not be the same spot on top. They use a crossover cap.

Another thing at the dealer.
Tip on going to the dealer
Ask that only a factory certified gasoline engine performance specialist work on your car.
Not all dealerships are concerned with how repairs are dispatched, and not all dealership techs bother to take advantage of the training offered by Ford (the vast majority of which is paid training). If the dealer is uncooperative, ask for your money back and call around for a dealer that will accommodate you.

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...

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
That GM set up getting the dist set on them sure is a pain.
Have you tryed redoing the dist hold down clamp?
Or is there a way you can change it over to a turnable/adjustable type dist?
MT

MT-2500....dmbrisket...Thanks for the advice....I followed your instructions and the rotor mark is bang on the 6 with number 1 at TDC.

The other thing I noticed was when if I clear the code after I start it the light stays off until I try to restart. Last night, I started it, cleared the code and drove it about 20 miles on the interstate....no code until I shut it down and re-started it. Not sure if this is a continously monitored system or not. The scanner data came up with no misfires but the timing advance data showed it didn't get past 30 degrees....

I think next week...I'll see if the guy who installed the engine can verify the reluctor wheel is in right side out....failing that I'll take it to a large dealership in the city and have them pull the engine under warranty....

MT-2500....dmbrisket...Thanks for the advice....I followed your instructions and the rotor mark is bang on the 6 with number 1 at TDC.

The other thing I noticed was when if I clear the code after I start it the light stays off until I try to restart. Last night, I started it, cleared the code and drove it about 20 miles on the interstate....no code until I shut it down and re-started it. Not sure if this is a continously monitored system or not. The scanner data came up with no misfires but the timing advance data showed it didn't get past 30 degrees....

I think next week...I'll see if the guy who installed the engine can verify the reluctor wheel is in right side out....failing that I'll take it to a large dealership in the city and have them pull the engine under warranty....

The computer controls timing advance when the engine is running depending on engine load and other data..
The cam retard setting which is seperate from timing will reset or check itself in the pcm whenever the engine RPM goes over 1000 RPM.
But not sure how long or when it trips the codes or turns on check engine light.
Watch the cam retart reading in the pcm while you are driving down the road.
If the dist rotor points dead on to the no on dist the cam retard should come out about right.
But on some I have had to crossdrill or file the hold down clamp to bring the cam retard setting to within specs. It should read as close to 0 degrees as you can get it. sometimes 1 -2 degrees 1 or +.
If it is off 20-25 degrees the rotor fireing is misssing dist cap. which can cause it to jump across and make spark a lot hotter and may burn up plugs or burn a piston.
MT

Just to update everyone....I took MT-2500's advise and we filed the distributor hold down clamp about a 1/4 of an inch....it's now reading a CAM retard of 0 degrees and the P1345 disapeared. Runs smooth with great acceleration and great fuel trim readings (within 0.78 on both banks for ST Fuel adjustment and 0-2 % for LT). Also did the Crankshaft variation relearn, it runs like new. We came to the conclusion that the reman CAM gear must be slightly different than the original, the scanner also reports 0 current and 0 history misfires after a lengthy drive cycle.

I called the GM tech line in Troy and the tech told me he sometimes recomends altering the hold down clamp ??? here's hoping the truck should be good for the next few years.

Just to update everyone....I took MT-2500's advise and we filed the distributor hold down clamp about a 1/4 of an inch....it's now reading a CAM retard of 0 degrees and the P1345 disapeared. Runs smooth with great acceleration and great fuel trim readings (within 0.78 on both banks for ST Fuel adjustment and 0-2 % for LT). Also did the Crankshaft variation relearn, it runs like new. We came to the conclusion that the reman CAM gear must be slightly different than the original, the scanner also reports 0 current and 0 history misfires after a lengthy drive cycle.

I called the GM tech line in Troy and the tech told me he sometimes recomends altering the hold down clamp ??? here's hoping the truck should be good for the next few years.

Thanks for posting back and letting us know how it went.
Glad you got it set and going good.
Should be good as new.
I have notched a few to get the cam retard set right.
Also I have not done it but I would think a person could also use a adjustable dist from a later v6 or v8 in it to. as far as I can tell a later v8 or v6 dist is the same dist just different dist cap on them and they are marked for the 6 or 8 cylinder rotor line up to cap.
I do not know why they ever put the fixed dist in them to start with.
MT

because now his ignition timeing is off by a hair

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

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

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

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 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

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.

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

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.

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

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.

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