Hot Start

1985 Volvo 244 DL, 98k, b23f. Car will not start after I have run hither, dither and so-forth. On or about my third/fourth stop car will not start. Turns over ok. Wait a few minutes and try again only with a little more stomping on the gas, it will start. Starts like it is hitting on only two cylinders, coughs once or twice, ramps up to a norman idle.

Cleaned throttle body, and inspected the accociated parts, hoses/filter. Replace the line pressure regulator.

Ran a quick check of the hall sender, voltage from the ecu.

Started to remove the fuel filter and check the pressure relief valve in the fuel pump, but lying on my back below the gas tank doesn’t seem prudent, or smart!

Check to make sure you are getting a good spark. Ignition coils are subject to heat problems.

Buy a spare spark plug and when it acts up, remove a spark plug wire, put the new plug on the end and holding it with the threads tightly against the block have someone turn on the starter.

If you get a good spark that is not it, if you get kicked back on your butt, you did not use an insulated tool to hold the plug, but you know the spark is good.

Sounds more like a fuel problem to me.

Strong candidate is a faulty engine coolant temp sensor, if this is bad it will cause the engine to overfuel. This would be borne out by the rough idling when the car eventually starts, the plugs are fouling. You can test this with an ammeter from cold to warm, you should see a significant resistance change as the engine warms up.

Could also be the air mass meter, if you disconnect it while the car is idling badly and it improves, that’s your problem.

But I’d suspect the water temp sensor more than anything else.


Thanks. Good idea,if I am alone when the hot start happens. I’ll get a new plug, but I’ll have a jumper wire to connect the plug threads to ground. That way I can crank and view at the same time. I’ll still be on my butt but without the agony.

Dick Gilligan