timing

[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.

 

[litlred]

this is what i think i know, the computer wont fire the injectors until the fuel pump comes on, or so i believe. the reason i say that is the computer i was using was from a 92 explorer manual, my engine and harness is from a 91, that was a automatic. i put that computer back in and now when i turn the engine over after a few seconds the fuel pump is coming on, and the injectors are now firing, and the engine will start on its own most of the time, the fuel pump sounds strong during prime, but when i go to start it it sounds extremely weak. the 91 computer also gave me a bap sensor out of range error code, so ive ordered the right computer 91 manual and i plan on picking up a new bap sensor. i have two questions though, first, is the engine harness/head light harness the same in a manual and an automatic(my donor vehical was a 91 explorer with shot automatic, im using the fm146 untill i can find a good m5od trans to replace it) with the trans harness being the only one different? and second, can the fuel pump show good pressure when running and not running, but still be bad? the test said to pinch the return line to test the max output, where do you pinch it, i thought the line was metal? i guess that was three questions... please help guys