Replaced fuel pump, still won't start, help!!!

[raptor125]

Hey everyone, still got that white 91 model that has issues. The owner replaced the fuel pump in it because the other one was weak. You could hold your hand over the line and it wouldn't blow off. Well another reason to replace it was because it wouldn't run any more. If you could get it to start, you had to hold down the gas for it to even stay running halfway. Well got that all done and now you hold your hand over the line and it will blow your finger off of it like it should. Well thought the darn thing would start, and no go. The explorer just won't start. Now it is just dumping gas and it seems to be like flooding. What could be wrong?

 

[PTBishop]

1. are you sure you have spark?
2. is it the right fuel pump
3. are you getting air into the engine?

 

[410Fortune]

lots of things, start with the basics.

Have you listened to the fuel pump? ON these trucks the relay and fuse are more problematic then the pump itself.

You can search for fuel pump, fuel pressure regulator, and similar on this forum and find a ton of info.

But as stated above, start with basics.
Do you have spark?
smells like you have fuel.
When you turn the engine over do you get any exhaust flow?
(clogged cat converter is just like a banana up the tailpipe, it wont run)



How many miles are on the truck?

 

[marragtop]

In addition to what the others have said, make sure all the vacuum connections are on the vacuum tree on the drivers side valve cover. Recently, my 92 blew all the connections off at once, and I had the same hard start/won't run condition.

 

[raptor125]

Thanks for the replies and to answer the questions! Yes, the fule pump is on and running perfect. It is the right pump, because he matched it up with the other one and plus it was a excact match on the parts number at the parts store. Anyhow, it has good pressure like said before, and I have no clue if it is sucking air or whatever. We think it is getting spark, but we should check that. To clarify the history of what happened, the truck was surging before and one day on the way home, it started to lose power. Well he had to lay on the gas to even keep it running. He got to his dirt road with it and it finally just quit running. It would crank, but no start. Still the same, even after we confirmed it was the fuel pump that went bad. So now we know we have the right pump and everything is hooked up right. Well have no clue if we are getting air into the engine or if anything else is wrong. I do know that it couldn't be a clogged cat converter, because we fixed that little problem with a temp fix. Gonna fix later, but nothing left in converter for now. The truck has 178,000 or so miles on it, maybe engine problem? We will check the vacuum lines and see if that fixes it, but if anyone got any ideas or need more info, would appreciate it. Thanks

 

[410Fortune]

check for spark first.

Is the CEL on?

 

[raptor125]

Checked spark. It is not that. All 6 plugs are firing. So what else coud it be?

 

[MrShorty]

I'm going to suggest checking a few things. Basically, all the engine should need to start is air, compression, fuel, and spark.

1) Air: Will it start if you open the throttle slightly (could indicate a clogged IAC)? Otherwise, there isn't much to interfere with air flow into the engine.

2) Compression: On an old engine it's possible to lose compression, but for this to cause a no start, you have to loose compression on several cylinders at once. This is probably the last thing to check.

3) spark: You say the spark plugs are firing, and it would be real hard for thye spark to be firing so far off that it won't start. This doesn't seem likely. one quick test wopuld be to pull codes from the computer. Some elements of the ignition system are monitred by thec EEC-IV computer, and will leave codes in the ciomputer in some no-start cases.

4) no fuel seems to be the most common fault. When you say it has pressure, how much pressure? 20 psi isn't enough for the engine to run; you need at least 30, and spec fuel pressure is 35-45 psi. If you haven't put a pressure gauge on it, I think that's the next thing I would do.
That only tests to see if fuel is getting into the rail. If the fuel injectors don't fire, the fuel cant' get into the cylinders and the engine won't run. ARe the fuel injectors firing? Any sign of gasoline in the cylinders?

 

[giosue_c]

Well, I don't know if this will help, but I recently solved a problem that I was having with mine. Sometimes it wouldn't start, but once I got it started it would run fine. Problem got so bad that I couldn't start it anymore. Finally after going through all the stuff that has been mentioned here (and then some) I started replacing relays. It was the ignition relay. (looked like one of these http://www.aroundoz.com/images/diy_instructions/relay_p2512rb.jpg). Hope that helps.

 

[Garbear]

Where is the ignition relay located?

 

[Brian_B]

.....Well got that all done and now you hold your hand over the line and it will blow your finger off of it like it should.....

I know this is a dumb question, but where are you checking the fuel pressure, at the schrader valve (on the fuel rail) or in the line somewhere near the tank?

What I am getting at is maybe its just the fuel filter plugged?

I know.....dumb suggestion with all the experts here.