Tuesday, June 14, 2011

Changing a Crank position sensor 1990 3.1L engine GM Chevrolet Beretta

Many of the newer automobiles use a magnetic sensor (cps) to determine where the pistons are in the engine. It uses the information gathered from a conglomeration of sensors, to determine the spark and fuel timing. When the sensor goes out, the car can not decide when and how to mix the spark and fuel.


  TEST THE SENSOR
The crank position sensor often causes an intermittent failure of the cars operation. To include stalling after warm up, and failure to start until a cool down period occurs.  IF THE CAR WILL START WHILE COLD ATTEMPT TO PULL CODES FROM THE EMISSION CONTROL COMPUTER
I WILL WRITE THAT PROCEDURE NEXT AND PROVIDE A LINK TO IT. THE DIAGNOSTIC PLUG IS UNDER THE STEERING WHEEL ( UNDER THE DASH) THE TOP MOST, RIGHT MOST, CONNECTORS ARE PIN A AND B , CROSSING THEM WITH ENGINE RUNNING PROVIDES CODES THAT EXCLUDE NO CRANK POSITION SENSOR. I SAY THIS BECAUSE IF THE CAR DOES NOT RUN, THERE WILL BE NO CPS READING DUE TO THE ENGINE NOT ROTATING

1.)
To test the crank position sensor you will need to locate the coil packs (Where the plug wires all meet together). Once you locate the coil pack you will note their are six plug wires and seven to nine 18gauge wires attached with either 2 or 3 plug connectors. On the same end as the five wired connector; There will be a 3 wire connector ( 2 18 gauge and a 22 gauge for the tachometer)


2.)
Unplug this sensor and the five wire plug to prevent the accidental starting of the engine.

3.)
Attach a volt ohm meter between the two 18 gauge wires. There should be a serious amount of resistance not equal to the test leads initial value, or a zero reading. Then ask an assistant to rotate the engine with the key. You should witness the changing of the resistance between the two conductors as the engine rotates.

4.)
The sensor cost about $22.00 at the local O'Reiley's. Some of the newer cars have two CPS; one behind the harmonic balance pulley and the one I am speaking of on this model. From under the car, look between the engine block and the trans-axle .  Roughly dead center of the engine block ( below the exhaust port of the center cylinder) will be a simple 2 wire plug connector approximately three inches above the " oil pan to block mating location".   That is your target!

5.)
Jack up the car securely!
Raise the car to a point where you can comfortably crawl / slither behind the passengers wheel.


6.)
The 5/16 " bolt that holds the sensor in place will most likely be the least likely savior for you. LEFTY LOOSEY will remove the bolt and in theory allow you to remove the sensor. After removing the bolt, and the snapped together connector.

Here is the part that will either make you smile or cry!

7.)
VERY CAREFULLY TRY TO GET A PAIR OF CHANNEL LOCKS ON THE SENSOR'S BASE AND TWIST IT EVER SO SLIGHTLY SIDE TO SIDE UNTIL IT SPINS FREELY.
This part is subject to extreme heat and becomes very brittle. It cracks, expands, and nearly welds itself into its hole. So be careful. Lets face it though; The sensor may break without ever coming out of the hole, and it may need some more effort to remove it. Now you must prepare to remove the oil pan.

8.)
Take the battery positive off the terminal with the same lefty loosey technique .

9.)
Remove the two 15mm bolts holding the starter and the three 10mm bolts holding the plastic inspection shield between the engine and transmission.

10.)
Drain the engine oil into a drain pan by removing the drain plug located on the center rear / right side of the engine oil pan AND REPLACE THE DRAIN PLUG!

11.)
 Remove all of the nuts and bolts from the oil pan ( about ten) 10mm Note that the bolt size is larger on two of them and they will have to go in the rear of the pan when re-installed


12.)
Place a jack on the transmission pan ....directly under pan bolts ( please do not crush your transmission pan by lifting the car with the jack K)

13.)
Your goal here is simply to create a space between the frame of the car and the oil pan, so that it may be lowered at the transmission end and slid back or to the drivers side of the car.

14.)
Lower the pan and note that the crank position sensor is accessible from inside the engine block. You will now have a place to pound out the sensor using a screwdriver and hammer.

15.)
Now after that is accomplished ..if the gasket is in any way damaged....replace it. completely clean the pan surface and the block surface and use a sealing agent or gasket glue to hold the replacement gasket in place during re assembly. Clean the pan of any metal shavings on the magnets ( if provided) and continue re assembly in reverse of dis assembly.

16.)
Snug down all of your pan bolts in a form of inner to outer criss crosses ( like a tire tightening ) to a snug tension on a standard 1/4" drive ratchet..(use the righty tighty method) . Make note that the little metal washer looking pieces are marked as to what side the nut goes on...NO POINT IN SNUGGING THEM ANY FURTHER THAN SLIGHTLY EXPANDING THE GASKET SEALER

17.)
Re-install the starter with the two 15mm bolts using the righty tighty method. Make sure they are tight. Try and picture how tight they were for removal. Snug them down well but do not try and break the socket k

18.)
Re install the inspection cover with it's three bolts an prepare to crawl out

Did you plug in the sensor? 
Did you put it's 5/16" bolt in for retaining the sensor?
Is the oil plug back in the oil pan?
Are all of the bolts tight?

19.)
Crawl out from under the car and pour roughly 4 quarts of new oil, or recycle the old oil back into the engine

20.)
Make sure sensor is plugged in where it was tested at the coil pack

21.)
Make sure the five wire connector is also plugged in.

22.)
Place the positive terminal back on the battery

Mental notes
Oil full? (check a few times as the windage tray in the pan delays the sinking of oil to the bottom of the pan


Sensor plugged in below?

Sensor plugged in at ecm? Coil packs?

Coil packs plugged in?

Lower the engine jack?

Lower the car to the ground?

Sunday, June 12, 2011

Finding Top dead center on GM V8


1. First you must locate the number one cylinder. (This will be the drivers side plug, closest to the front of the engine.)

2. Remove the coil and distributor cap and have an assistant rotate the engine by using the starter. (observe the location and rotation of the rotor and the engine pulleys)

3. Now remove the furthest front spark plug on the drivers side of the car and lower a long screw driver into the hole.

4. Using a six point socket and a rachet. rotated the engine slowly in the direction the pulleys were spinning durring starter function. ( This will be an easier task with all of the spark plugs removed from the head )

5. Carefully watch the screwdriver for change in elevation with the rotation of the engine.

6. Observe the line marked on the harmonic balancer pulley. As this line approaches the teeth on the timing stand off, So will the piston be reaching the Top Dead Center (TDC) location, and so will the rotor be pointing nearest the #1 plug wire post.

7.Finally, the screw driver will reach its furthest "TOP" point, and under the valve cover, the two rockers to that cylinder will be loose (if you want to expose that)

8. Looking at the rotor and which post it is pointing at,eill expose the Number one position.

9. Back the timing line off the TDC mark by about six degrees , or three marks and twist the distributor itself into the position that lines the rotor up with a post towards the center of its twistable range.

10. Install the distributor cap and place number one wire on the post directly over the rotor tip. THAT IS WIRE ONE LOCATION

11. Following the direction of the rotor rotation, install  wire eight, then four, three, six, five, seven , and two

<strong>Other usable tid=bits</strong>
In some cases, the cylinder number might be cast on the intake port right above the cylinder.

The distributor rotation may also be indicated, by having an arrow cast onto the intake manifold, near the distributor

Friday, June 10, 2011

Changing NON- Anti lock disk brake pads

Does the car have anti-lock brakes. I will cover anti lock brakes later, but it is very crucial that you do not use this method on anti-lock brakes!



Some it is okay on, and others it will destroy the processor on....So here we go



There are usually two bolts that hold the caliper on the hub assembly



1. Crack loose the lug nuts, then raise the car and remove the wheel.



2 .Remove the two bolts holding the caliper to the hub assembly and pry the top of the caliper off the rotor, This will require a forward motion, as they pry off towards the front of the car, not the side.





3. After removing the pad closest to you, you can either use a C- clamp, or an actual caliper compression tool. Leaving the pad on the actual caliper piston, you then screw the bolt in a tighten direction to push the piston back into the caliper.




4.  This action pushes the fluid back into the master cylinder and creates enough space in the caliper for the new brake pads.




5. Remove the C-clamp/ caliper compressor, and remove the used pad.



6. On most cars the rotors should wiggle right off, and you should take them in to be resurfaced. As the brakes wear on the rotors, they make them as slick as glass. Having them turned will increase the friction available when the brakes are applied, and push the caliper back when in the rest position, assisting in the lowering of brake noise




7. Purchase anti squeak glue when you buy your pads. Although you have to change organic pads more often, they are much kinder and gentler to your rotors.  Apply the anti squeak to the caliper piston and the back side of the outer pad. This will keep the pad attached to the caliper and resist the chances of chatter and squeaks



8. Roll the caliper back around the rotor, with the pads propperly around the rotor.



9. jostle it around so that the two bolts line back up to their original location and tighten them down well.



10. If you look closely, the bolts are actually slides for the caliper to slide on...Make sure they are clean enough to do their job.



11. All clips and or pins that were in should be placed back as you are rolling the caliper in place!



Special notes


When one side is excessively worn, it is very possible one of the calipers has a sticky spot and may wear fast



deep groves in rotors will cause them to be too thin, and quality machine shops will not turn them beyond their minimum thickness



The passenger side will be a mirrior image of the drivers side, so assembly will seem backwards



Soft brake hoses will over expand under pressure and cause weak, spongy brakes