'90 240DL won't start

[radiolaser]

Having trouble with my '90 240DL not starting. It will turn over and act as if it is going to take off, but won't. This started a couple of weeks ago. At first, it would start in the morning, but as it warmed up through the day, it would have trouble starting in the afternoon heat. Now, it's in the garage and I can't get it going at all. After sitting a few hours it will start up, but die after a second or two. When I try to re-start it, no luck. All I can smell is a gas odor.

Please help...could it be the timing belt has slipped? Could it be that the fuel pump has gone out? If so, how hard is it to drop the tank and put in a new pump?

Any thoughts/suggestions would be much appreciated. Thanks!

[denisond3]

First, it not likely its a fuel pump problem. They arent particularly temperature sensitive, and are likely to either work okay - or not work at all. If you smell gas though, it probably means the pumps are working, but it could be a leaking fuel line - depending where you smell the gas. If you smell it outside the car, have a look underneath, (after having turned the ignition on several times, but without starting the car). When you turn the key on, the fuel pump (or pumps) will run for almost 2 seconds, then shut off. This will happen each time you cycle the ign. key on, and in a quiet location, you should be able to barely hear the soft hum from the back of the car. If there is a fuel leak, you may be able to find it by looking afterward. If you smell gas in the engine compartment - do the procedure above and look for the wet spots.
Referring again to your symptoms: If you had a clogged fuel filter, I would expect it would start okay, but not run well when you wanted to speed up, or go uphills.
Your symptoms could maybe indicate a bad fuel pump relay. This is a fairly common failure item on 240s that are approaching 20 years of ago. I dont know where the relay is located on your car. On our 89 sedan it is on the front 'wall' of the footwell where the passengers feet would reach if they stretched them out. You have to take off a snap-off panel to see it.
And you should check for spark. With an assistant to crank the starter, you pull one spark plug wire off, and put something into the end, so you can hold the thing about 1/4 inch from a metal part of the engine. By the time the crankshaft has made 2 turns, you should have seen a nice blue spark. If you smell gas much, dont do this near anything or anyone you value. In other words, be very careful anywhere near where you smell gasoline.
While a timing belt can slip, it would prevent your engine from starting at all, or if it did start, it would hardly have the power to move away from the curb. You said this had been occuring for several days. The timing belt slipping would be an event where it was fine one day - and non-running after the belt slippage, with no exceptions.
It could be an injector that is leaking fuel, which will lower the pressure for the other injectors to where the engine wont run.
Your symptoms could also be a bad ignition coil or bad pickup module in the distributor, or a bad spark computer. These things can all be temperature sensitive as they are failing.
If your 240 is like ours, one (main) fuel pump is under the car, ahead of the rear wheel on the drivers side, and the other (transfer) fuel pump is inside the fuel tank. With the sedans there is an access plate in the trunk, and with this plate off you can see the fittings on the top of the tank that lead to the fuel pump/fuel pickup, and fuel gauge sender unit.

The pumps are pricey, so hope its a fuel pump relay; they are reasonable, and easy to replace.