Mazda MX-6 1998, Workshop Manual

Page: 179 / 1282

TROUBLESHOOTING [ENGINE CONTROL FS]
STEP INSPECTION ACTION
5 Install fuel pressure gauge between fuel filter
and fuel distributor.
Start engine and run at idle.
Measure fuel line pressure at idle.
Is fuel line pressure correct at idle?
Fuel line pressure
210— 260 kPa
{2.1— 2.6 kgf/cm2, 30— 37 psi}
Yes Go to next step.
No Zero or low:
Check fuel pump circuit.
Check for open fuel pump relief valve.
Check for fuel leak inside pressure regulator.
Check for clogged main fuel line.
High:
Check pressure regulator for high pressure cause.
Check for clogged fuel return line.
6
Remove and shake PCV valve.
Does PCV valve rattle?
Yes Go to next step.
No Replace PCV valve.
7
Is there restriction in exhaust system? Yes Check exhaust system.
No Go to next step.
8
Is brake system functioning properly? Yes
Go to next step.
No Check for cause.
9
Check for contaminated MAF sensor.
Is there any contamination?
Yes Replace mass air flow sensor.
No Go to next step.
1 0
Is engine compression correct?
Yes Check for valve timing.
No
Check for cause.
1 1
Verify test results. If okay, return to diagnostic index to service any additional symptoms.
0 1 -0 1 A -1 51