Herman

I have a 1999 grand 4.7 it turns over but wont start when I bought it did not run and had some of parts removed I am getting a p1391 code I have replaced the cam and crank sensors. i also took it to the dealer to have the transponder keys programed just in case they said that the keys were already programed but could not verify without starting it so... It had been sitting for three years in a very moist environment so maybe corrosion? your help would be greatly appreciated

giwill

hey bud i have that same jeep with a 6.5 zone off road lift kit and BF 32" and just put a new 4.7 in it because i blew a head on my old one.

I had some problems when setting the timing and could not get help with from anyone so i went online and bought the program from ALLDATAdiy.com for that same jeep it cost me like 27 buck and it was worth every penie i suggest you do same same.

I look on my program for the same jeep and it takes you through some step to troble shoot the code you put online the p1391 and from what i gather from it it sounds like a CMP sensor but it could be other things and it take you through the step to track it down.

Hope this helps

Herman

Thx that well my next step. just checked and no power to crank sensor so I'll start tracing that tomorrow any common places to start looking?

giwill

not really sure just make sure that your wires are not cut or bad anywhere. and i would go through the entire fuse box in the jeep and under the hood one by one taking them out and checking them no matter what they are for, sometimes the fuses will burn out for no reason at all dont be shy take them all out one by one just to be sure beats having to track down that wire.

Herman

I've check all fuses and relays so I guess it's time to look for broken, shorted out or corroded wires.

giwill

I would, but now i dont know if that Sensor is supposed to have power to it at all times it might only have power when your turning the motor over and when the motor is running so you might try replacing it because if CMP sensor is bad it will not start

giwill

Any luck yet?

Herman

Not yet I think I might have some kind of short jeep turns over slow or maybe a bad ground but I have 12.5 volts at the battery

Herman

read one of your other post how did your jeep react with the timing off and how do you set up the timing

Herman

still need help with timing

Bustedback

Are you checking for voltage at the sensors with a 12 volt test light? That will screw the SBEC up and cause expensive problems. You be using a DVOM for checking sensors.

giwill

well my jeep would start but not run unless i pressed the gas i can tell you how to check to see if the timing is off here's how check


CAUTION: The 4.7L is a non free-wheeling design engine. Therefore, correct engine timing is critical.

NOTE:

• Components referred to as left hand or right hand are as viewed from the drivers position inside the vehicle.
• The blue link plates on the chains and the dots on the camshaft drive sprockets may not line up during the timing verification procedure. The blue link plates are lined up with the sprocket dots only when re-timing the complete timing drive. Once the timing drive is rotated blue link-to-dot Alignment is no longer valid.

Engine base timing can be verified by the following procedure:

1. Remove the cylinder head covers.

Fig. 4

1. Using a mirror, locate the Top Dead Center (TDC) arrow on the front cover. Rotate the crankshaft until the mark on the crankshaft damper is aligned with the TDC arrow on the front cover. The engine is now at TDC.

Fig. 5

1. Note the location of the V8 mark stamped into the camshaft drive gears. If the V8 mark on each camshaft drive gear is at the twelve o'clock position, the engine is at TDC on the exhaust stroke. If the V8 mark on each gear is at the six o'clock position, the engine is at TDC on the compression stroke.
2. If both of the camshaft drive gears are off in the same or opposite directions, the primary chain or both secondary chains are at fault. Refer to Timing Chain.
3. If only one of the camshaft drive gears is off and the other is correct, the problem is confined to one secondary chain.
4. If both camshaft drive gear V8 marks are at the twelve o'clock or the six O' clock position the engine base timing is correct. Reinstall the cylinder head covers.

SINGLE CAMSHAFT TIMING

NOTE: to adjust the timing on one camshaft, perform the following procedure.

1. Using Chain Tensioner Wedge, special tool 8350, stabilize the secondary chain drive. For reference purposes, mark the chain-to-sprocket position.
2. Remove the camshaft drive gear retaining bolt.
3. Carefully remove the camshaft drive gear from the camshaft.
4. Re-index the camshaft drive gear in the chain until the V8 mark is at the same position as the V8 mark on the opposite camshaft drive gear. NOTE: When gripping the camshaft, place the pliers on the tube portion of the camshaft only. Do not grip the lobes or the sprocket areas.

Fig. 6

1. Using a suitable pair of adjustable pliers, rotate the camshaft until the Alignment dowel on the camshaft is aligned with the slot in the camshaft drive gear.

Fig. 7




Fig. 8

1. Position the camshaft drive gear onto the camshaft, and install the retaining bolt. Using Special Tools, Spanner Wrench 6958 with Adapter Pins 8346 and a suitable torque wrench, Tighten retaining bolt to 122 Nm (90 ft. Lbs.) .
2. Remove special tool 8350.
3. Rotate the crankshaft two full revolutions, then reverify that the camshaft drive gear V8 marks are in fact aligned.
4. Install the cylinder head covers.

Herman

Checked with multi-meter

giwill

Any luck Yet

Herman

well the timing was way off both upper chains are very loose wear pads show a lot of wear tensioners aren't touching so i have ordered a complete kit, I'll let you know how it goes. Thank for all the help