86 volvo 240 dl 4 door, fuel pumps test ok, plenty of fuel, electrical system seems to be working fine (battery good, starter good, coil, cap/rotors/wires, etc etc), will turn over but will not start. Appreciate any tips, I have read in the manual that (if memory serves) the temp sensor can prevent the car from running. Jet tronic fuel injection system (obviously very early).

Any advice would be appreciated. THANKS!

 

*all* bosch injection systems were jetronic until they switched to Motronic and integrated the injection and ignition (newer than any 240 or 740/940). You likely have LH 2.2 Jetronic, which is EFI (Electronic FI) vs the even earlier KE-Jetronic aka CIS-E (Constant Injection).

two things keep a car from starting. A) its not getting fuel, or B) its not getting spark. troubleshooting LH 2.2 requires a test light or volt meter so you can see if you're getting pulses at the injectors, and assorted other things. I believe the 240 FAQ's cover these test proceddures.

 

I would give the spark plugs a check for flooding, always solved my problem!

 

Make sure the 25 amp fuse under then hood (should be in a white fuse holder) is not blown. This fuse controls the main ECU and fuel pump relay. If fuse is ok make sure your fuel pump relay is clicking(white rectangular relay located under passenger kick panel) grab it in one hand as you turn key to on position you should feel a "click" keep holding it and try starting the car you should feel another "click" if you do not feel the "clicks" you probably have a bad or weak fuel pump relay...replace it. But always check fuses first and for corrosion on fuse panel and 25 amp fuse under hood. You should be testing each fuse with a test light that you trust. If all checks out then test for spark from the coil. You really need 2 people to do this unless you have a test light for spark. pull the coil wire off the distributor cap and put it as close as you can without touching it to the top of the strut mount bushing nut and bolt. Have a friend try and start the car if your coil is good you should see a spark jump out of the wire to the ground(strut mount nut and bolt) If spark at coil then move on to testing spark at each wire. Put coil wire back on top of distributor cap. Pull each wire individually and test for spark the same way just find a close ground to test on. If spark there, most likely a fuel problem. If no spark check the connections on your ignition module under the hood front of car passenger side (black box) sometimes the prongs get worn out and you need to either put metal sleeves over them to make them tight again or tighten the plug female connections carefully with a pick. But if you find that you have good spark the move onto to testing for fuel. You can spray some starter fluid into bellows(where air mass meter is hooked up to) and then try starting the car. If it starts then you know for sure that you have a fuel problem. If it does not start and you have not checked your plugs, pull your plugs and make sure they are not fuel soaked(flooded). If it does start with the starter fluid you probably have a weak fuel pump and not getting enough fuel pressure. You will either need a fuel pressure gauge or bring it to your local trusted Volvo mechanic. I am not sure of your skill level or the tools you have access to so I tried to give you some quick "back yarder" methods to test for fuel and spark but in reality unless you know what you are doing I would have it towed to your trusted Volvo mechanic. Or you could purchase a Bentley manual for $40 if you plan on learning how to and working on your own car. It will be the best $40 you ever spent guaranteed! There are several things that could cause a car not to start but the basics of it are you need to have spark and fuel. Now in saying that there are several components that could go bad that could cause a lack of spark or fuel. i.e. fuses, corroded fuse panel, bad ground connections, broken timing belt, bad ECU, bad fuel pump relay, bad fuel pumps, bad tune parts(plugs,cap,rotor,wires), bad mass air flow sensor, vacuum leaks, bad ignition module, bad wire harness, bad fuel injectors, etc etc etc you get my point. Get a Bentley manual and some basic testing tools (test light, fuel pressure gauge, multi meter, spark or pulse tester, timing light etc.) the manual should tell what tools you should buy if you plan on learning and working on or diagnosing issues on your car. Take your time, ask a lot of questions to guys that have been doing this a long time and gather some spare parts at your local junk yard so you can do some testing. Hope this helps and btw: it's usually(90%) of the time something REALLY simple causing the problem. I just got a 240 for free because it was only running on 3 cylinders...it was a cracked distributor cap( $6.00) and 2 minutes labor! For a 88 245 with 130K! So my point is if you don't have test tools like most DIY's don't...check all the simple things first....then decide if you want to continue and invest in tools or just have it towed to a TRUSTED VOLVO mechanic...Good luck to you and ROLL ON!!!

 

Thanks for all your tips friends, here's the problem (Which, no mechanic had been able to diagnose yet, so I am a little ticked about it). The head gasket was slightly warped, and seeping antifreeze into the rest of the engine. Its a testament to these volvo engines that they can run that "Sick" (antifreeze had permeated the air intake, the oil pan, etc) and it still ran even though it was bleeding, ever so slightly, antifreeze out of the cooling system. Anyway, its all back together and hope fully the head isnt warped. I will keep you posted. THANKS AGAIN FRIENDS

 

That's why diagnosing over the internet is so difficult...really have to see the car. I wouldn't have thought a blown headgasket because you did not mention the car running poorly etc. you just said it won't start. Now typically unless the headgasket is blown BADLY and yes causes a warped head even with a blown headgasket these and most cars will start and run. Must have been really bad...that is why I always say to do a compression check..this also allows you to see the condition of the plugs...glad to hear you got it fixed and thanks for the update. FYI- I would have figured it out if I saw the car in person guaranteed.