I am assuming that the engine is cranking (turn over) but will not run.
Most gasoline engines would need only two (2) elements to run; fuel
(spark) at the right moment
. Based on your post, "not appeared to have jumped timing
", it would then be assumed that the "at the right moment" (at least for the spark
) is good. Next to check then would be for the presence of spark; this could be performed by removing one of the spark plugs, reconnecting the said plug to its wire, let it rest on any exposed metal and crank the engine. There should be a pulsating spark at the end, if yes then problem is most likely elsewhere, if none, then next to check (depending on the engine type
) would be the:
- high tension wires;
- distributor cap;
- ignition module;
- ignition B+12.
If there is spark and yet would not run, then the fuel delivery to the engine has to be checked. There are two checks on the injector:
- electrical - pulsating +12 on each of the injectors while cranking;
- fuel spray - you need to remove all and check if each will spray fuel (while cranking). For safety reasons, pls have several disposable containers ready to catch the fuel, paper towels or rugs to wipe/clean off any spilled raw fuel. If yes, problem is elsewhere, if not and no pulsating +12 while cranking, ECM wiring or connector, if there is pulsating +12 yet no fuel spray, then defective injectors or defective high pressure pump.
In some instances, it could be the alarm/security/immobilizer acting up which prevents the engine to run.
Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.
Good luck and kind regards. Thank you for using FixYa.