timing

[litlred]

I'm sorry, there was only two sensors, the third that ran through the manual harness now is in the engine harness.

 

[litlred]

Okay traced wires from automatic trans harness, there is a green/yellow strip wire on the black connector that spliced in with the pink wire that goes to the neutral safety switch on trans to the gray connecter at the main harness.

 

[litlred]

After spicing it into my current harness, it seems to be helping, I don't know what that wire goes to though, I can't find it in the wiring diagram. There are still 3 more wires from the black connector that I'm assuming are part of the automatic trans that I don't need but I can't find them either.

 

[AllanD]

Don't worry about "TFI" a 4.0 doesn't have one...

AD

 

[kimcrwbr1]

Looking closer at the diagram It kinna looks like the start circuit throws the emissions into a closed loop using the white and black wire thru either the clutch or neutral sense to a black and white but dont know if you can put battery voltage to the sensors safely on mine the sensors had 5 volts going into them in normal operation but what I understand the computer runs in an open loop until it warms up then it closes the loop. Is the computer you have for a manual transmission or does that make a difference.
white/black to the computer and the two switches neutral, clutch
black/white to the sensors from the switches all five sensors
see if you are getting voltage to the sensors with the key in start that would be the black and white common to all of them.

 

[litlred]

Wouldn't the loop be closed if the clutch is in or in neutral?

 

[kimcrwbr1]

yes that is the goal how many connectors does the neutral switch have on it on the tranny find the two that are closed in neutral those go to wht/blk and blk/wht and all ways check for shorts also the other ones are for the backup lights unless that is a different switch the clutch switch is another thing it is actually a triple function switch do you need to push it fully for the starter to work. And I was reading a little closer you mentioned it worked a little better when you had charged the battery that could be very well the problem if your battery is low you should have around 12.5 volts on a charged battery take it in and get it checked replace it if it is bad as soon as you start it make sure the charging system is working correct clean all the grounds the tech library has a good section on charging you should be getting around 14.8 to 15 volts at 1500 rpm no more than 2.5 volts over battery and with the lights on high beam and the heater or a/c on high no less than .5 volts over battery at about 2000 rpm. Just a thought

 

[litlred]

Yea, ive had the battery and altenator tested, both are good. It wasnt charging when I first swapped the 4.0 in. But all it was was a fuse. Its starting better, but not like it should.

 

[kimcrwbr1]

Is your battery fully charged you can test the other thing by unplugging the start wire on the starter and have someone turn the ignition to start while you test the black/white wire on one of the engine sensors for voltage the water temp would be the easiest in neutral clutch in

 

[kimcrwbr1]

start wire on the start relay

 

[litlred]

What should it read?

 

[kimcrwbr1]

from the schematic battery voltage what is it reading

 

[litlred]

okay i gave up on it for a while, but here we go again....
this is what i know

Engine is 4.0 liter from 91 explorer
engine has new plugs, new wires, a new crank sensor, good battery, good altenator
fuel pressure shows 55 psi when running, 45-50 when not running
engine very hard to start on own, but if i spray starting fluid directly in intake it will fire right up and run near perfect.
idle while running is near perfect with little to no hesitation when throttle applied, so im thinking there is nothing wrong with the coil pack.
just drained the tank, added 5 gallons of fresh gas and changed the fuel filter today.

any ideas on what to check next?

Can anyone tell me what tells the injectors to fire? is it related to what tells the coil pack to send spark to the cylinders?

 

[Sasquatch_Ryda]

You fuel pressure is way high...should be 30 psi when idling.

 

[litlred]

could that cause my problem? is the fuel pressure regulator causing this?

 

[litlred]

okay, the first time i checked the fuel pessure it was 55psi running with a tester i rented. Today i went and bought a tester and it checked 45psi while running... also it was 45 while not running.. i did this test i found in the video on this page

http://www.2carpros.com/dia/test_fuel_pressure.htm

my pressure drops when i goose it slightly, it doesnt jump at all. according to the video i have a bad pressure regulator

i tested my 94 bronco with 5.8 the same way, and it has 40 psi with key on engine off and 30 psi at idle... also when i goose it, it jump close to 38psi then backs down when i let off...

my question now is would the fuel pressure regulator cause it to hard start?

 

[Shran]

Yes it could. You definitely have a bad regulator.

 

[litlred]

i noticed today the vac line to the regulator is cracked, i gotta make my way to the junk yard and find another.

 

[litlred]

okay, put a new fuel pressure regulator on as well as fixed vac line. still didnt fix problem. but the fuel system checks as it should, about 39 not running, and 30 running, when i goose it it goes up 5-7 psi... what else could keep it from starting on its on? like i said before, if i spray starter fluid in intake it fires right up and runs great till i shut it off.. all ideas are better than what i have... nothing...

 

[litlred]

what tells the computer to fire the injectors in cranking mode? my injectors are not firing while cranking. they will fire while running if i spray starting fluid to get it to run.