[vegas TJ driver]

97 4.0 in a TJ. Engine cranking rpm sounds slow. Battery is fully charged. Spark to coil. Spark to plugs. Fuel pressure 40 psi. Power to fuel injectors. Am I missing something? Suspect timing chain is the issue. Got significant backfire when cranking and adjusting distributor counter clockwise.

 

[CJ7-Tim]

Base timing is set at TDC, and the PCM makes all further timing adjustments. Do not mess with the distributor.

Is, or was, the Check Engine Light ON ? What trouble codes were recently noted, current, or pending ?

What specifically is wrong, slow to start, or no-start ? Why do you say the cranking is slow ? Once started, does it run normally ? What diagnostics point to timing chain issues ?

 

[jtec]

Spec is 49.0 psi ± 2 psi
SO that 40psi is LOW esp now as the temps go down.

sound's to be cranking SLOW -
battery, oil, cylinder having fuel water.

I suggest a scanner, Like Tim mentioned check for CODES and resetting 'SYNC' after moving dist.

 

[Jerry Bransford]

Measure the battery voltage on the posts then measure it again on the battery connector WHILE THE ENGINE IS CRANKING. Have a helper work the ignition switch while you measure the voltage. The battery needs to stay at 12 (or close) while the engine is cranking or the battery is going bad or is not fully charged. If the battery stays at 12 volts but the voltage on the connector is dropping while the engine is starting that indicates a bad battery connection. Physically remove both battery connectors and wire brush them and the battery posts then securely reinstall them so they're tight enough that they can't be moved around on the battery posts with even considerable hand pressure.

 

[Boweache]

really great for a start

 

[TheBoogieman]

CPS is also something to check out.