1990 240 no spark and injector pulsation - 1990 Volvo 240

YOU NEED EXPERT TEST EQUIPTMENT,,YOU NEED DEALER TECK HELP. TAKE IT OR TOW IT TO A DODGE DEALER

you did not say what year and yes, it makes a difference. Pull off an injector connector and with the key on, one of the two wires should have 12 volts. If not, check the injector fuse. If OK, it could be a crank sensor or cam sensor (crank sensor is more likely if there is also no spark).

check for injector pulsation with a noid light if it dosnt puls suspect pcm but check all fuses first there is one for injectors

Depending on the make model and year, usually the computer controls the ground circuit to the injectors.

At injector's, need to check if you have ground pulsation, to check, connect test light on pos (+) battery terminal, now your set to check ground, at injector harness, probe wire's, while some one cranks engine, look for pulsation, if you don't have pulsation, it will need a computer, injector pulsation is control by the computer, if no pulsation, then no fuel can get into cylinder.

Without knowing what kind and year truck be hard to say, but I would check injector pulsation, might be getting gas to injector rail but not pass injector's.

I would check the camshaft sensor.

fuel pressure regulator is the only thing left that can cause no start due to fuel problem

ok if it is getting spark at spark plugs that rules out ignition, let go to fuel, needs to check fuel pressure and also injector pulsation, if no pulsation fuel will not get into cylinder's, also a knock sensor will not keep an engine from starting, it controls ignition timing once engine is running.

Hi,

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 and ignition (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;
• distributor cap;
• rotor;
• 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.