Intake gasket

MATT8043

MEMBER
1996 GMC C1500
5.7L
V8
2WD
AUTOMATIC
220,000 MILES

The truck ran great but was leaking water out the back side of the intake. I tore it down to replace the lower intake gasket after putting it back together it would not idle. As you try an start it it almost seems like the battery is weak. It is brand new and never did this before tear down. I took it for a short drive on the road it seemed to run okay until you let off the gas. Then it also started getting hot it did backfire. I put in TDC with the intake off so I know it was on compression when I put the distributor back in I had the 8 mark with the notch on the distributor, but when it went in place it advanced itself close to a inch forward! I am not the best at all with timing any help would be greatly appreciated. It is all I have and I have four kids to get around take care of.

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

Good morning.

The distributor is actually the cam sensor. It has to be set using a scan tool for cam/crank correlation.

Do you have a scan tool to perform this operation?

Roy

TEST PROCEDURE
The ignition timing cannot be adjusted. The distributor may need adjusting to prevent crossfire. To insure proper alignment of the distributor, perform the following:

1. With the ignition OFF, install a scan tool to the DLC.
2. Start the engine and bring to normal operating temperature.

IMPORTANT: Cam Retard Offset reading will not be accurate below 1000 RPM.

3. Increase engine speed to 1000 RPM.
4. Monitor the Cam Retard Offset.
5. If the Cam Retard indicates a value of 0° +/-2°, the distributor is properly adjusted.
6. If the Cam Retard does not indicate 0° +/-2°, the distributor must be adjusted.

ADJUSTING PROCEDURE
1. With the engine OFF, slightly loosen the distributor hold down bolt.

IMPORTANT: Cam Retard Offset reading will not be accurate below 1000 RPM.

2. Start the engine and raise engine speed to 1000 RPM.

3. Using a scan tool monitor Cam Retard Offset.

4. Rotate the distributor as follows:
4.1. To compensate for a negative reading, rotate the distributor in the counterclockwise direction.
4.2. To compensate for a positive reading, rotate the distributor in the clockwise direction.

5. Repeat step 4 until 0° +/-2°, is obtained.

6. Turn the ignition OFF.

7. Tighten the distributor hold-down bolt to 3 Nm (25 lb. Ft.).

8. Start the engine, raise engine speed to 1000 RPM and recheck Camshaft Retard Offset.