How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dan Your Own Question
Dan
Dan, Auto Service Technician
Category: Car
Satisfied Customers: 3490
Experience:  GM ASEP A.A.S. 14 years GM experience. Mark of Excellence and Professional Guild awarded.
4976144
Type Your Car Question Here...
Dan is online now
A new question is answered every 9 seconds

1999 gmc: tranny..vin..crank relay,cam relay,and starter

This answer was rated:

I have a 1999 gmc C6500, 26 foot box truck,with a 7.4 gas engine,with a manual tranny , with A/C .the trucks last 8 vin #.s are XJ505766. my problem is I have no spark,I have changed the following items, crank relay,cam relay,and starter. I,ve checked fuses on the outter fire wall, and the inner fuse block.I hope you can help
Any trouble codes setting, is the check engine light ever illuminated and is a scan tool available to look at engine sensor data (especially the crank sensor input or RPM)?
Customer: replied 8 years ago.
a friend used a scan tool early today,and said something about RPM,and maybe a loose wire , but he cant return until 5/7/08. thats too long.hope you can help. thanks john PS engine light never on. thanks

Did the engine stall out or just not start one day out of the blue? Any signs or symptoms before this? Is there spark from coil to cap and rotor and then from cap to plugs at all?

Customer: replied 8 years ago.
Reply to Dan's Post: hi, I drove the truck early that day,than parked it for several hours,it started I than drove it 2 city blocks,and she died, I was doing about 10 mph. this engine has coil to plug ingintion,which is new for me.
Customer: replied 8 years ago.
Reply to Dan's Post: hi, I drove the truck early that day,than parked it for several hours,it started I than drove it 2 city blocks,and she died, I was doing about 10 mph. this engine has coil to plug ingintion,which is new for me.PS I think I was down shifting to the stop sign
Customer: replied 8 years ago.
hi dan, any other thoughts about the truck ??
thanks john
#00-06-04-016: Hard/No Start, Possible DTC P1345 (Check Cam Sensor Alignment/Replacement Proc) - (Apr 11, 2000)

Subject:Hard Start or No Start, Possible DTC P1345 (Check Cam Sensor Alignment/ Replacement Procedure

Models:1999-2000 Chevrolet and GMC Medium Duty C6, C7 and B7 Models
with 7.4 L Engine (VINs B, D -- RPOs L21, LP4)

 



Condition

Some customers may comment on an intermittent hard start or no start, and/or a possible MIL light with a DTC P1345.

Cause

The cam sensor alignment may be off by one tooth and could possibly cause any of the previous concerns from a customer.

Correction

Check cam sensor alignment and correct as necessary using the following procedures.

Camshaft Position Sensor Diagnosis


    Object Number: 290953  Size: SH
    Click here for detailed picture of above imageidth=

    Important: Prior to camshaft sensor removal and/or to check the camshaft sensor position, align the timing mark on the front engine cover and the crankshaft balancer to 0 degrees top dead center (TDC). Be sure the bank 1 cylinder 1 is on the compression stroke, or that the intake and exhaust valves are closed.

  1. Disconnect the negative battery cable.
    Object Number: 625962  Size: SH
    Click here for detailed picture of above imageidth=
  2. When properly installed, the reluctor wheel cutout should be in approximately the four o'clock position and should line up with the stamped number "9" on the camshaft position sensor housing.

Camshaft Position Sensor Replacement


    Object Number: 290953  Size: SH
    Click here for detailed picture of above imageidth=

    Important: Prior to camshaft sensor removal, align the timing mark on the front engine cover and the crankshaft balancer to 0 degrees top dead center (TDC). Be sure the bank 1 cylinder 1 is on the compression stroke, or that the intake and exhaust valves are closed.

  1. Disconnect the negative battery cable.
    Object Number: 276382  Size: SH
    Click here for detailed picture of above imageidth=
  2. Remove the interior engine access cover if applicable.
  3. Disconnect the electrical connector from the camshaft position sensor.
  4. Remove the camshaft position sensor retaining bolt.
  5. Remove the camshaft position sensor.

Installation Procedure


    Object Number: 43756  Size: SH
    Click here for detailed picture of above imageidth=
  1. Align the spot mark on the camshaft position sensor gear with the paint mark on the camshaft position sensor lower base.
    Object Number: 625961  Size: SH
    Click here for detailed picture of above imageidth=

    Important: This alignment is prior to installation with the shaft in proper alignment but not in the final installed position.

  2. Remove the cover from the camshaft position sensor.
  3. Use a long flat blade screwdriver to rotate the oil pump driveshaft to engage the tang of the camshaft position sensor drive gear.
    Object Number: 276382  Size: SH
    Click here for detailed picture of above imageidth=
  4. Without holding the reluctor wheel, guide the camshaft position sensor into the hole in the intake manifold until the camshaft position sensor is seated. The reluctor wheel will turn clockwise as the camshaft position sensor is lowered into the engine.
    Object Number: 625962  Size: SH
    Click here for detailed picture of above imageidth=
  5. When properly installed, the reluctor wheel cutout should be in approximately the four o'clock position and should line up with the stamped number "9" on the camshaft position sensor housing.

    Important: Refer to Fastener Notice in Cautions and Notices.

    Important: The camshaft position sensor hold down clamp must properly align with the mounting hole in the intake manifold. Repeat the installation procedure if the proper alignment is not obtained.

  6. Install the camshaft position sensor hold down clamp and bolt.

    Tighten
    Tighten the bolt to 33 N·m (24 lb ft).

  7. Install the camshaft position sensor cover and screws. Do not over tighten.

    Tighten
    Tighten the screws to 5 N·m (40 lb in).

Dan and other Car Specialists are ready to help you

Related Car Questions