Fuel Pump/Timing chain

I think that I am being taken by a mechanic. I took my 2001 ford explorer sport trac to him because it would not start. he says it's the Fuel pump and he replaces it. Now he is saying that it is the rear timing chain and that it still won't start. Question, What all should be checked if the fuel pump is working but the truck still won't turn over and start. He says that he has checked and the pump is working. could it be a filter that is causing the issue and is there a reset or something for the fuel pump to be recognized by the computer. And I have no manuel but is it possible at all that the wrong fuel pump was installed and that is the issue? Thanks in advance for the help.

Welcome to the forum!

When you say, "...still won't turn over and start," what do you mean? Does the engine crank, but it doesn't start and run, or the engine is not even turning over? If the engine is not turning over, the fuel pump will not have any effect on that, that would be more like a starter or ignition switch.

If the engine cranks fine but won't start, then the technician needs to check for fuel pressure (which I would hope they did before condemning the fuel pump), and if there is fuel pressure, then check for spark.

If the problem is the timing chain, the spark could be effected, and if the chain is broken, there would be a noticeably different sound to the engine cranking (due to no compression).

-Rod

the engine will turn over but not start. the mechanic says that he changed 4 of the 6 spark plugs and it didn't start. he also did not change the filter when he changed the fuel pump. Is there a certain sound to listen for to determine if the timing is the issue. and if so is it cheaper to rebuild the engine than replace the right timing chain.

Often if the timing chain has just stretched, you'll still get the occasional sputter when cranking the engine like it wants to start. It may or may not actually start, but if it does, then it will often run very rough like it has a nasty vacuum leak.

I'd suggest since he has had the 4 plugs out, he measure the compression on the engine. Also, he certainly should have the capability to check the fuel pressure. Also, put the scan tool on it and check for codes. If the crank sensor is not giving any reading, it should show up as a diagnostic code.

It certainly would be less expensive to change the timing chain than to rebuild the engine, but I wouldn't expect the timing chain to be your issue. If it truly is, then there may be some defect with the engine and you may want to consider a different engine. How many miles are on this engine?

-Rod

The engine has 116,000 mile on it. I am the second owner. Also he said that he got no codes when he put it on to the scan tool. He has stated that because if the location of the timing chain that he claims is the issue that it would be cheaper to rebuild or replace the engine. Also he says that the number of other parts that would have to be replaced it is better to just replace/rebuild the engine. I have my car, but I don't believe anything that he is saying to me right now. I have learned a lesson here. thanks for all the help.

I don't believe the 4.0L in the Sport Trac is an interference engine, so damage if a timing chain broke or skipped a tooth should not be that extensive, and it would certainly be a bigger effort to replace/rebuild the engine. If he's so concerned that a lot of parts are damaged, a compression check on a few cylinders should qualify his fears quite easily.

Has he checked the fuel pressure and checked for spark? Those items should have been early on the troubleshooting list. An experienced technician should be able to "hear" a broken or stretched timing chain in the sound of the engine cranking.

If I were in your shoes, I would certainly get a second opinion. Ask around to your co-workers, neighbors, etc. and see if they have any shops that they trust and recommend.

-Rod