Back to the facts:
1.) Car is an 87 that has a Mass Air conversion done by adding & moving pins in the existing harness.
2.) Engine has a “B” cam installed?
3.) The intake manifold was removed for the installation of the “B” cam.
4.) Engine will not idle with MAF connected
5.) Computer has code 66 set, probably due to disconnecting the MAF while the engine is running.
Questions :
Will the engine run off idle? 1500-3000 RPM
Will the engine run smoothly at 1000-1500 RPM?
Are you sure about the camshaft being a “B” cam?
Possibilities:
A.) MAF conversion miswired
B.) Vacuum leaks from manifold installation
C.) Firing order off
D.) Faulty MAF
E.) Faulty computer
Do the easy stuff first:
a.) Check wiring of Mass air conversion:
Keep in mind that this is the view from the front side of the connector.
Pin 50 MAF signal source
Pin 9 MAF signal ground
Pin 40/60 MAF power ground
Pin 37/57 MAF switched 12 volt power
b.) Check for adequate vacuum – should see 17”-21” at 1000-1500 RPM. Less than that, start looking for vacuum leaks.
c.) Check to verify firing order:
Remove the #1 & #3 spark plugs. Put your finger in #1 spark plug hole. Crank the engine over until you feel compression on #1 cylinder. Slowly turn the engine until the TDC mark and the timing pointer line up. Mark TDC on the balancer with chalk or paint. Put your finger in #3 spark plug hole and crank the engine 90 degrees. You should feel pressure trying to blow past your finger. If you do not feel pressure, repeat the process again. If you feel pressure, it is a HO firing order.
No pressure the second time, remove spark plug #5. Put your finger in #1 spark plug hole. Crank the engine over until you feel compression on #1 cylinder. Put your finger in #5 spark plug hole and crank the engine 90 degrees. If you feel pressure now, the engine is not a HO model, no matter what it says on the engine.
Using a small carpenter or machinist square to mark the harmonic balancer off into 90 degree sections may be helpful here.
A 15/16 deep socket & breaker bar or ratchet may be used to turn the engine.
The HO firing order is 1-3-7-2-6-5-4-8.
Non HO firing order is 1-5-4-2-6-3-7-8
d.) Swap the MAF with a known good working one. The original MAF was a 55 MM unit .Since you work at a Ford dealership, check the parts catalog to verify the MAF sensor part number matches what you have.
e.) Swap the computer with a known good working one.
1.) Car is an 87 that has a Mass Air conversion done by adding & moving pins in the existing harness.
2.) Engine has a “B” cam installed?
3.) The intake manifold was removed for the installation of the “B” cam.
4.) Engine will not idle with MAF connected
5.) Computer has code 66 set, probably due to disconnecting the MAF while the engine is running.
Questions :
Will the engine run off idle? 1500-3000 RPM
Will the engine run smoothly at 1000-1500 RPM?
Are you sure about the camshaft being a “B” cam?
Possibilities:
A.) MAF conversion miswired
B.) Vacuum leaks from manifold installation
C.) Firing order off
D.) Faulty MAF
E.) Faulty computer
Do the easy stuff first:
a.) Check wiring of Mass air conversion:
Keep in mind that this is the view from the front side of the connector.
Pin 50 MAF signal source
Pin 9 MAF signal ground
Pin 40/60 MAF power ground
Pin 37/57 MAF switched 12 volt power
b.) Check for adequate vacuum – should see 17”-21” at 1000-1500 RPM. Less than that, start looking for vacuum leaks.
c.) Check to verify firing order:
Remove the #1 & #3 spark plugs. Put your finger in #1 spark plug hole. Crank the engine over until you feel compression on #1 cylinder. Slowly turn the engine until the TDC mark and the timing pointer line up. Mark TDC on the balancer with chalk or paint. Put your finger in #3 spark plug hole and crank the engine 90 degrees. You should feel pressure trying to blow past your finger. If you do not feel pressure, repeat the process again. If you feel pressure, it is a HO firing order.
No pressure the second time, remove spark plug #5. Put your finger in #1 spark plug hole. Crank the engine over until you feel compression on #1 cylinder. Put your finger in #5 spark plug hole and crank the engine 90 degrees. If you feel pressure now, the engine is not a HO model, no matter what it says on the engine.
Using a small carpenter or machinist square to mark the harmonic balancer off into 90 degree sections may be helpful here.
A 15/16 deep socket & breaker bar or ratchet may be used to turn the engine.
The HO firing order is 1-3-7-2-6-5-4-8.
Non HO firing order is 1-5-4-2-6-3-7-8
d.) Swap the MAF with a known good working one. The original MAF was a 55 MM unit .Since you work at a Ford dealership, check the parts catalog to verify the MAF sensor part number matches what you have.
e.) Swap the computer with a known good working one.
