I have a 1992 Explorer with about 136k miles on it. Recently it began to have startability problems. I thought it was because I put a tank of cheap-o gas in it, but since fillng up with my usual gas, the startability problems havent gone away.

Basically it only happens when the engine is cold. In the morning, i turn the key, wait until i hear the fuel pump stop, and turn the key again, and the engine turns over and sputters and stalls. Then i turn the key again, and it starts right up and runs fine. I do notice a slight smell of gasoline. (engine flooded???) During operation, the truck has plenty of pickup when I hit the gas pedal, and it doesnt sputter or hesitate during acceleration at all.

So far I have changed the air filter, the fuel filter, cleaned the idle air controler valve on the air intake, and disconnected the negative terminal on the battery to reset the onboard computer.

so far, no luck eliminating the cold start sputters, but since i changed the fuel and air filters, cleaned the idle valve and reset the computer, the truck seems to have a little extra pickup and a little smoother idle. But it could just be my imagination........

Anyway, my next step is to add some fuel injector cleaner during my next gas fill up.

No engine light comes on during starting or normal operation of the truck.

does anyone have any suggestions that I might have missed??

Clean the mass air sensor?
Clean the O2 sensor?

When I cleaned the idle air control valve, it had some black stuff all inside. the part on the intake where it connects to also had the black stuff.
Would it hurt if I sprayed some carb cleaner directly into the throttle body air intake while the engine is running??

Thanks all for your help

Best Regards,

Jakerot

 

In addition, I have seen other posts in this forum detailing hard starting and people have said the IAC valve and the temperature sensor were the problem. Other people have suggested looking at the fuel pressure regulator. Where is this located?

I am wondering if just cleaning the IAC was enough, or if I should replace it alltogether?

Thanks again in advance for everyone's help.

Regards,
Jakerot

 

ok I have a 92 ford exploder 4x4 4.0L P engine and same problem, I have cleaned o2, new fuel pressure regilator, new vacume hoses ( had a tranny vacume diaphrame mess up all lines) then checked time and time again fuel pressure, but in fact, after a shop friend of mine looked at it said that the fuel pum was at pressure, but was slow pumping, 1pt in 30 seconds, while it needed to be 1.5pt in 30seconds, I am replaceing this as we speak I will let you know. But I hate this cold start problem!

 

Here's what I would try. Next time you go to start the engine when it's cold, turn the key to the ON position (not START) like you usually do. When the fuel pump stops, turn to OFF then to ON until the fuel pump stops and back OFF. Repeat this for a total of about 5 times and then try to start it. If it starts up normally, then the check valve in the fuel pump is bad.

 

chspyder,

Thanks for the reply.

Definately keep me posted about your fuel pump replacement. If it works for you, then I will have to drop the fuel tank and replace that sucker...............and while I am at it, I will be able to fix that stupid fuel guage problem I have too...............yes, I am one of those Explorer owners whose fuel guage is permanantly stuck on "E"

some nasty stuff came out of my old fuel filter when I replaced it so I am sure more of that nasty stuff is lodged inside my fuel pump.

If you could, send me a private e-mail with your results: jakerot(No Email Addresses In Posts!).

good luck

rgds,

jakerot

 

Mikeman

Thanks for the reply. I will try your suggestion tomorrow morning.

So basically if the check valve is not closing properly, the fuel flows back into the fuel tank when i turn the engine off. After a while, all the fuel from the fuel line will migrate back to the tank, leaving no fuel for start-up.

Could the check valve problem get worse or cause problems in the engine, or is merely a start-up annoyance?

Thanks for your help.

I will post results tomorrow.

Regards,

Jakerot

 

OK

Let the fuel pump run 5 times this morning before starting the ignition and it started right up.

Tomorrow I will let the fuel pump run 4 times and see what happens.

If this check valve is leaking, will it cause problems in the engine, or is it merely an annoyance?

Thanks

Best Regards,

Jakerot

 

Merely a startup problem. I would use a good fuel system cleaner, like Techron to see if there is contamination around the check valve causing it to stick.

Winford

 

>Merely a startup problem. I would use a good fuel system
>cleaner, like Techron to see if there is contamination
>around the check valve causing it to stick.
>
>Winford


Good Idea, but I have tried this till my wallet was empty, so far there have not been ANY changes to my fuel lines/system or my gas mileage from the cleaners. Also there are many goverment tests that have had little or no effect with the cleaners.

 

You all can debate this till you are blue in the face or get a $40 fuel pressure test gauge set and really find out what is going on.
I fixed a hard cold start issue and backfire issue at the same time using one of them.
Per the manual, the fuel pressure should run between 30-35PSI with engine running and vaccum line on the pressure regulator, and between 35-45 PSI with the vacuum line removed and engine running. You are probably correct about the lack of fuel in the injector rails being the root of the hard starting issue. The real issue is wheather the fuel pump check valve or the fuel pressure regulator is the cause of the problem. By using the pressure test gauge, you can see if pressure falls off over time in the injector rails after the engine is shut off. If it does, you can then open the fuel return line at the frame in the engine compartment and see if fuel is leaking past the pressure regulator. If so, replace the regulator, if not, then the check valve in fuel pump is suspect, as well as a possible leaking injector.
Dialtone

 

Hey sorry to tell you all that the fuel pressore gague is NOT ever accurate to predict the problem I had proper fuel pressure and my pump is bad, thanks to a previous post about the valve on the fuel pump stickking open I tried this, and in fact it was stickking, but I still feal that a 120$ pump is worth it because you dont want to drop the tank 2 times!

thanks to all I will post if the new pump fixxes my problem!

 

OK, i got it down to 2 turns of the key before turning the engine over. I let the fuel pump run twice, then fully turn the key and the engine revs up to about 1100 rpm and then settles down to about 800 or so.

I will try the fuel system cleaner.

I am still playing with the idea of dropping my tank. with 137k miles, i am guessing the fuel pump could be on its way out anyway, and the float is already dead on the sending unit. Seems like there are lots of problems going on in my fuel tank.

thanks all!!

rgds,

Jakerot

 

Did you ever figure out what the problem was?