# 1996 chev k3500 7.4/454 crank/cam corelation p1345



## dethtech

So im about 15hrs into trying to time this truck and i'm about ready to drive it off a cliff. The distributer was replaced recently and its had the 1345 code and a knock sensor code continually come up. ive put the distributer in myself at least a dozen times, both forward and back a tooth from the hotstamped 8 on the housing at tdc. only runs in the one spot but has -34 cam retard. ive pulled the front cover and the timing marks are alligned. we've tried another distributer with the same results. replaced the crank sensor and both knock sensors. scoped the cam sensor and the igniton. followed any little tip we can find and still nothing works to fix it. any help would be great. just dont tell me the distributer is in incorrectly like everybody else has. i leave the floor open to you guys...


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## octaneman

*Re: 1996 chev k3500 7.4/454 crank/cam correlation p1345*

Hi dethtech

Apologies for not getting to you sooner.

It would help if you told us why was the distributor changed and what was the original problem with the truck ? When you reinstalled the distributor what steps did you take to ensure it's proper timing. You will have to be aware that adjustments for EFI distributors are not the same as the old vacuum advance type. All vehicles today have a timing advance connectors that have to be either disconnected or jumped depending on the model type. If the timing is to far advanced the engine will ping or create a hard start issues. 
A crank sensor tells the computer that the piston is at TDC and the cam sensor tells the computer when to fire the ignition coil(s). To properly re-set the timing of your engine, locate and disconnect the timing advance connector, bring cylinder no.1 to TDC, check the position of the crank pulley marks in relation to 0 degrees TDC. Look at the position of the distributor and align it to the proper tooth mark, be careful that you do not place the distributor 90-to-180 degrees off time. Tighten all hold down bolts securely and start the engine adjust the distributor as needed and reconnect the advance. 

post back your findings.


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## dethtech

not to be rude or anything ocatneman, but im less than a year from having my journeymans ticket. i understand all of that. i was given the vehicle with a new distributor put in it and told to figure it out. ive put it to tdc, aligned the timing mark, followed every instruction to the letter and its still off. i found a broken wire on thurs and repaired it bringing it from -34 to -21. ive checked the distributor position repeatedly and its always where its supposed to be. as far as i can find there is no advance wire to disconnect, thats the first thing i asked and i looked all over my resources for anything about it in this truck and cant find it.


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## Basementgeek

Did a "school" give you this truck to fix as part of the class work?

If so our Rules prohibit any further help.



> EDUCATIONAL ASSISTANCE
> 
> While we are happy to promote the education of users, we feel it is inappropriate to circumvent the learning process by directly assisting with assignments and projects of an educational nature. Direct answers to school or college assignments are not allowed and will not be given. However, if a user is having trouble comprehending a certain topic, the members and staff at TSF will be happy to provide assistance with understanding the topic.


BG


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## dethtech

no. my boss did. thats why i need it done and out as soon as possible.


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## Wrench97

The Vortec V8's need the Tech II or similar scanner to set the timing you can't do it the conventional way. 
What wire did you repair? Was it one for the cam or crank sensor?


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## dethtech

it was a solid pink wire into the black connector on the vcm. the truck had a jet tuner pack on it that we removed because of intermittant sensor failure readings. the one scotch-lock that it used all but destoyed that pink wire. was just holding on by a thread


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## Wrench97

The guy who invented Scotch Locks should be hanged from the highest tree, those things cause more problems then they fix.

Are you still getting the P1345 code now?


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## dethtech

yea, all that it fixed was bringing the retard from -34 to -21. i dont get why, but it did. i'm still waiting for the auth to check the wiring continuty between the sensors and the vcm.


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## Wrench97

Pull the Cam Sensor out and check it metal shavings stuck to tip.
Do you know why the Distributor was changed? Because of this problem or another problem?


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## dethtech

have no idea. was given to me with the new one in it. we even tried installing one we ordered ourselves and it was still off.


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## dethtech

found something odd while i was checking wires. there seems to be a short somewhere in the ENG-I fuse circuit that the cam sensor gets its ign signal from. im removing the fuse box now to look closer at it.


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## SABL

Circuitry is the best place to start but I have not noticed any reference to mileage. Any slack in timing by chain or gear wear may have an impact on performance. The vehicle is 13 yrs old with mileage unknown.... wear will take a toll and sensors may not reflect the underlying cause. I am "heavy" type of mechanic and deal with basic engine functions and related failures. 

Get your readouts with a scan but beware of what may be old age. My vehicle is 1 yr older than yours and has 239K miles.... any reading with a scanner may very well be moot due to normal wear. A scanner will assume that all components are up to snuff and not take into consideration that there may be wear on critical components.


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