6 degrees before top dead center on the 305 TPI
by adjusting the fuel injection screw
You can set the injector pump timing on a 4HF1 Isuzu engine by adjusting the fuel injection screw. The adjusting screw will restrict the amount of fuel to be injected.
The initial timing is set and controlled by the vehicle's PCM (Powertrain Control Module). DO NOT try to set the timing by moving the distributor. The distributor is used to index and synch the fuel injection timing on 3.9/5.2/5.9 liter Magnum engines.
If it is petrol then it is probably the ignition timing not set correctly. If it is diesel then it is probably the injection pump timing not set correctly
To set the timing you unplug the temp. sensor in the thermostat housing and set the timing to 12 degrees before T.C. with the automatic trans.
no need to set the timing for it automatically set its valve.only the cdi needs timing for they controls the electricity to burn your fuel....
There is no timing adjustment on fuel injected models the ignition timing is set by the ECU . Regards:
after diconecting the computer, the timing should be ajusted and set at zero deg.!!! 00000
Here are a few things I would check. Air filter. Does it need changing. Fuel lift pump and filter. working correctly and clean Carburettor. Are the jets clear and unclogged Spark plugs. Is there a strong spark. Clean and gap set correctly. If it has fuel injection as opposed to a carburettor check the injection pump, fuel lines and injectors. Injection timing. Ignition timing
Which engine have you got? There is a choice of.... 8v carb 8v single point injection or 16v multipoint injection regards Andy
you will need to have your computer reprogramed to adjust timing,fuel mixture etc
If the vehicle is NOT fuel injected/computer controlled, then set it at 8-10 degrees. If it is fuel injected/computer controlled, you need to set it at 0-2 degrees with the timing wire disconnected.