i need help please any one... i have a 96 ford ranger 2wd 2.3l with the 8 spark plug set up. ok here is the start the truck started to have problems getting started normally in the morning. after first start up it would be very easy but maybe have to turn key twice. then one day it would only spin over. so since then i replaced CPS,water pump, temp sensor, starter, flywheel, IAC, spark plugs, and wires. it had started back running for a god 2 weeks. now it has started back. the other morning it was around 30 or below and like i said it acts worst when its cold. i still haven't been able to start it. my teacher told me to change fuel filter which i did but still wont start. it spins over and acts like it wants to catch but doesn't. i have check all fuses relays. i hear the pump come on when i turn the key. i just dot know what else to do. i also tried to do a fuel pressure test but all it does is when i turn the key and the pump come on the needle goes up close to 15psi but when the 2 secs stop on the pump it slowly goes back to zero. now if i sit there and turn the key on off on off making the pump go on off on off the pressure will go up higher but when i stop it will slowly go down. i think i have said and explained all i can if some one could give me an idea on what to do test or try i would really really appreciate it. i been changing parts on cars and truck for over 4 years and i am currently in diesel school and i am a vet. so anything you through at me i can handle . please some one help me out thanks in advance

 

1996 Ranger will need 30-40psi of fuel pressure to start and run.

Fuel pressure should hold for a few months, not minutes, hours or days.....months

So you have a pressure leak.

If you don't smell gasoline then there are 2 places for the pressure leak.
1. The Fuel Pressure Regulator(FPR) is on the fuel rail with the fuel injectors.
It will be connected to the Return fuel line and have a vacuum hose attached.
Inside the FPR is a rubber diaphragm valve with a spring, the spring holds the valve closed when engine is off, when engine starts the vacuum will pull open the valve and allow extra fuel to flow back to the gas tank in the Return line.
Engine vacuum is high at idle when less fuel is needed, and low when accelerating when more fuel is needed.
If this valve isn't closing all the way then fuel pressure is lost when engine is shutdown, if valve was deteriorating then problem would get worse and worse over time until it can't hold any pressure.
Also remove the vacuum hose on the FPR, check that there is no gasoline in that line, if so replace FPR.

2. Fuel pump has a Check Valve inside, it is basically a flap that is pushed open when fuel pump is on, and then closes tight from the 30-40psi back pressure when pump is off.
This holds the fuel pressure above 25psi when pump is off.
The check valve is part of the fuel pump not a separate part, so whole fuel pump must be changed if that's the problem.

If you are careful not to damage the Return Fuel hose you can put a clamp on it, pinching it closed, doing what the FPR should do.
Then put on the fuel pressure gauge and turn key on and off a few times.
If pressure is holding now then replace FPR, that's the leak.
If pressure is still not holding then Fuel Pump check valve is the issue.

This is assuming engine was running well prior to this problem, a fuel injector can get stuck open and leak fuel and pressure, but this would go into the engine causing very rich running and noticeably lower MPG.

 

I feel like RonD could just build a perfect ranger from the ground up lol

 

Thanks a whole lot i will check those out when i get out of class.

 

OK so here is my update i haven't been able to get to the truck since last time i post. so today i bout a starter cause it went out from trying to crank it last. and after i put it on after turning the key twice it cranked up. its been sitting with jack stands under the front for two days. so while it was crank i hooked up fuel pressure tester an it read 34 psi. when i unhooked the fuel pressure regulator it jumped up 10 psi. so i cut the truck off the pressure went to zero. i turned the key heard the pump come on and for that brief second it came on the pressure went up to 45psi. but soon as the pump cut off it went back down to zero. so my question is now whats my next step?

 

Yes if you remove the vacuum to FPR pressure should go up, which means it is probably OK, BUT............that means fuel pump check valve is leaking the pressure, so best to make sure.

Carefully clamp off Return fuel line, then repeat test, if pressure stays at 30-40psi with engine/pump off, then replace FPR, it is leaking pressure back to tank.

If pressure still drops down then it's the fuel pump's check valve.

You can drive this way, you just need to turn key on and off a few times before trying to start engine