Why won't my car stay on?

(2011-02-21 15:20:19)

1. Noelia #2 Due Oct 1st! Says: i have a 93 400e mercedes, its difficult to get started n once i get it srarted it wont stay on. it will stay on as long as your foots on the gas but as soon as u take it off its likely to go off again. it runs smooth, i dnt hear anything that sounds different in the engine or tranny. does any one know what this could be?

2. MasTec 1970 Says: There are a couple of things that come to mind on the 400E 4.2L engine and this is a common one and it has to do with a n engine wiring harness, Inspect wiring harness in conduit alongside the valve cover to the Mass-Airflow Sensor and where it exits the control unit housing (E-Box.) Open taped sheath and flex wires manually. If insulation crumbles as you do so, harness replacement is needed. This should be done before any further diagnosis is attempted. Collateral damage, such as PCM damage caused by shorted injector wiring has been seen. Also the is a switch on the throttle body it is called a CTP (closed throttle position) switch if this switch does not open as expected then the throttle is released the engine will stall!

3. tlworkroom Says: a 400e? come pick me up and I'll help you with it!!

A car needs 3 things to be running--air (oxygen), gas (fuel), and electricity (spark).

As someone else mentioned, a simple check of both fuel filter and air filter will help rule out those things.
However, if your fuel pump is going out, that would prevent fuel from being sent to engine enough.
Since it's a 93, you should have a tune up. that would take care of checking most everything that would prevent engine from running. Also, consider getting new spark plugs wires. I thot wire would last life of car, but only about 5 years. I had older car that wasn't running well, someone suggested, and I got new ones and solved myproblem, which was the old wires wasn't sending good enough spark (electricity) to ignite the fuel.

So a general tune up would help to check out all possibilites for this problem.

4. Nelson Mendez Says: Check the flange dipper on the attarack pin, is should modulate co-syncally on the #1 pistons. If not check for pits, I find an ioniscope tuned to the exhaust of the #2 valve's resonate harmonic usually indicates the source of the loss. just kidding :)

But seriously you might just need either an air filter or a fuel filter, total for both at most $10.00 and if you go to autozone, they will switch them out for you for free. I would just get them both.

if your in the northern states what might be happening is that the air filter is collecting a lot of moisture and then freezing, thereby clogging the air intake. a replacement will fix this, same thing can be happening in the fuel line, I would just replace them both :) also you might want to try some fuel treatment, another 3 bucks at most. this will clean out your fuel injectors. and take the moisture out of your gas tank and gas line.

btw: if you go to auto zone ask them to run a computer check just to check things out, this is also done for free but I would still do all three above. fuel filter, gas line filter and fuel line treatment, all can be done in less than 10 mins and for less than 15 bucks :)

5. Tex G Says: You need to take it in to the shop. And have them check it out. It could be several items. TPS and O2 sensor. Or it could be in the computer. It could in the MAPS which is in the computer on most car's and truck's.

6. jamesbergen50 Says: The idle screw needs turned in. To set the idle so it don't die. Or it has fell out and is missing. This is located on the carburetor. Usually takes a short screw driver to adjust. Or a allen key. Any kid in the neighborhood who owns a car should be able to do this for you. Set the idle control screw.

7. bandit_60 Says: sounds like it,s not getting enough gas to keep it going. start by changing the fuel filter and check the air filter. it can,t run if it can,t breathe.