crank no cold start

[Paradox972]

I have looked at tons of threads but none seem to fit my exact issue. I recently bought a 93' explorer sport 2door. I will start with the issues. 1)will not start in the morning or once the engine is cold unless I spray ether into the TB. 2) When I am driving I have slowly step on the gas pedal if i press down to much it just bogs down. now what I have done. replaced, idle air controller,plugs and wires, tried different working coils, throttle position sensor,crankshaft sensor,fuel filter, mass airflow sensor, and a brand new battery. the fuel cutoff switch is ok there are no broken vac lines and no frayed wires and all the grounds are good. I swapped relays arounds for the eec and fuel pump . I am the 3rd owner it has 141,x.. miles on it. when its in park I can rev the engine all day long but once its under load it bogs. I'm broke and can't keep throwing money at it (only paid 650$) I cannot tell if its the PCM or the fuel pump or something else entirely . I tried the paperclip key off test and the engine light never blinks it just stays solid ,even while cranking. Please and Thank you for any help. oh and it is NOT California emissions.

 

[Bootless]

I had the same exact problem go to AutoZone get a loaner fuel pressure tester hook it up see what your pressure is in park then put it in drive give it some gas and see if it drops down happened ti me when I got my truck I tried everything ended up fuel pump give it a shot and let us know

 

[natenkiki2004]

As Bootless said, get the fuel pressure checked.

Also, it's a bit concerning that you can't get codes. I made a video on the subject, make sure you've got it hooked up right:
https://www.youtube.com/watch?v=bNkD_0s5_dw

 

[Paradox972]

I did the test just like in your video and soon as i turn the key the cel is on and stays on no matter what . i am so frustrated right now no words to even try to explain . I am out of gas so I can't try the engine on test till tomorrow , gas gage is broken, just pissed . also when it is running the idle is a little low but smooth .

 

[natenkiki2004]

You're sure you got the connections right? Might have to get larger-sized wire to ram into the pins, cleaning the oxidation and corrosion off.

 

[Paradox972]

they looked clean . i'm going to dig up some shovelhead clips i have in the basement to see if that works . Wife made me walk away before i put my hand thru some glass. I'll let you know if the clips make a difference .

 

[Paradox972]

nope no change have a solid connection and the light just stays on no matter what i do

 

[Paradox972]

Ok I just had someone turn the key while I listened at the fuelfiller and the pump runs constantly instead of shutting off after a few seconds and it does burn rich when its running so is this the pump? PCM or something different altogether that I'm missing

 

[Centaurious]

If the pump runs but will not shut off it is not building up pressure.

A. check the fuel pressure. If it is low before replacing the fuel pump remove and check the Fuel Pressure Regulator at the front of the passenger side fuel rail. If the diaphragm is busted you will have the problems you describe when it sucks fuel through the vacuum line into the plenum.

B. If the fuel pressure regulator is ok, pull the pump and check for pin hole leaks between the pump and the round mounting flange. You will see no signs of an internal leak inside the tank but you might hear it spraying inside the tank with the cap off.

Good Luck.

 

[FR-425]

My bet is on the FPR

 

[natenkiki2004]

As far as I know, there's no fuel pressure sensor. The pump doesn't care what the pressure is, nor does the computer. The PCM runs the pump when it sees a crank signal. If the crank signal goes away, so does the fuel pressure. When you first power up the PCM, it runs the pump for 2 seconds and shuts off since it doesn't see a crank signal. The fuel pressure regulator has no relation to when the pump runs, it just regulates what the pump is pumping because the pump runs at full speed all the time the PCM tells it to.

 

[2stroke]

Exactly, I've been through the whole fuel system multiple times, and I don't see any kind of sensor at all. Its possible there is some relays somewhere stuck on, but I don't know about it. I only know of the single fuel pump relay under the hood. If that's not bad, the ECU is.

 

[Centaurious]

Sometimes I forget how primitive these are in comparison to modern tech.

 

[Paradox972]

yesterday after trying to start it once or twice with no luck i pressed the shrader valve and fuel sprayed like a pressure washer I dont have a gauge but when i bought the truck we put one on and the pressure went from nominal (35-45) i think to almost 60 at one point but the engine was already running and hot. and it always starts when its hot like a brand new car turn the key for a second and it fires right up. I can buy a pump or a PCM today but not both . or up my insurance and drive it off a bridge lol kidding

 

[Centaurious]

All I can suggest at this point is to read the KOEO, CM, and KOER codes and see if they might give a clue. Maybe a temp sensor out of range and not telling the PCM that the engine is cold?

Good Luck

 

[MrShorty]

i think to almost 60 at one point but the engine was already running and hot.

On a 1st gen Explorer, there should be no good reason for the fuel pressure rising much above that 45. If it is spiking to 60, something is wrong with the fuel system -- most likely something is preventing return flow to the tank (either a fuel pressure regulator sticking closed or a kink or other restriction in the return lines).

When it won't start, is it showing signs of "flooding"/too much fuel?

 

[Paradox972]

it gets to much fuel . and when i tried the key off test the light never went out or blinked just stays on solid

 

[MrShorty]

it gets to much fuel

In that case, one of the first things I would do -- get a fuel pressure gauge on it and verify that the pressure is running too high. Then work on figuring out why the pressure is too high and fixing that condition.

when i tried the key off test the light never went out or blinked just stays on solid

That sounds like the PCM is not getting the signal to enter the KOEO test. Perhaps a break in the wiring between the self-test connector and the PCM, or something internal in the PCM. There isn't much to these circuits outside of the PCM. Make sure the wiring is intact between the self-test connector and the PCM. I might try jumpering the STO and SIG RET pins at the PCM to see if that triggers the PCM to enter self-test mode.

 

[Paradox972]

thanks for all the help you guys are great . someone made me an offer for a running car thats newer and I had to take it. if I did'nt need to get my son to school and back I would have kept it but sadly had to get something else for the time being . I do appreciate all the help and hopefully this thread helps someone else.

 

[larrydd999]

I can certainly understand why you decided that way. I won't work on a vehicle unless I have a reliable alternative way to get to work, which means having two reliable vehicles all of the time. I do like the older vehicles and to not have a car payment, but it does mean paying more attention to the 'little things' to be certain they don't develop into big problems.