Pontiac TRANS AM 1977 Service Manual page 544

6-1 4 1977 PONTIAC SERVICE MANUAL
K. Hard Starting
-
Cold (Engine Cranks OK) 1. Visually check the following:
a. Vacuum hoses for splits, kinks and proper
connections. See hose routing charts,
Section 6E.
b. Air leaks at carburetor mounting and intake
manifold.
c. Ignition wires for cracking, hardness,
proper connections, and carbon tracking.
Repair or replace as necessary.
2.
Check ignition timing per emission control
information label.
NOTE: If timing is too early
-
speed up
engine to see if timing mark moves. If not,
check for stuck mechanical advance. Refer
to Section 6D. Repair as necessary and
recheck timing.
3. Check the following:
a. Choke, throttle linkage and fast idle cam
for sticking.
b. Carburetor flooding.
Clean and repair as necessary. If repairs
are necessary,
see
carburetor, cleaning and
inspection, Section 6C.
4. Connect secondary voltage output meter or
scope to engine. Using insulated pliers,
check output with spark plug wire removed.
Output voltage should read 25 KV or above.
If any reading is below speicifcations or
arcing occurs, stop engine, remove distributor
cap and visually inspect for moisture, dust,
cracks, bums, etc.
Check distributor for:
a. Worn shaft
b. Bare and shorted wires
c. Faulty pick up coil, module, ignition coil
and shorted condenser. Repair or replace
as
necessary.
5. Remove spark plugs. Check for cracks,
wear, improper gap, burned electrodes, heavy
deposits. Repair or replace as necessary.
6. Test fuel pump by connecting hose from
carburetor fuel feed line to a suitable
container.
Start engine and let idle for
15
seconds.
Pump should supply 1/2 pint or more.
If more than
1/2
pint, check filter in &r-
buretor. Replace if necessary. If less than
1/2 pint, for mechanical pump go to step 7.
Go to step 9 for electric pump.
NOTE: Check current to electric pump. If less
than
12.2
volts, check pump wiring circuit.
See
Section 6C.
7. Disconnect irilet hose at pump and connect
a vacuum gage. Crank or run engine until
maximum vacuum is reached. If less than
12
inches, replace pump. If more than 12 inches,
go to step 8.