2.3L ('83-'97) Engine won't start, unless I spray starting fluid in throttle body

[Iedector]

My 1992 Ranger won't start. It fires a little bit and acts like it wants to start, but ultimately won't. If I spray starter fluid directly into the throttle body, it will start and run and continue to run, and will usually start right back up if I shut it off, but a few mins later it won't start again. I've checked for spark and everything is good, and I quickly tested the TPS by disconnecting it, but no dice. I guess it *could* be a fuel issue, but since it runs, I don't think so, and I replaced the fuel pump a couple years ago.

When I do get it running and I rev it, it stumbles a bit like its going to die, but then it revs.

 

[fastpakr]

It would be very interesting to know the fuel pressure before and during the startup process.

 

[Iedector]

I will pick up a fuel pressure tester this morning and report back.

 

[RonD]

Fuel pressure at the engine for 1992(1997 and earlier) should be above 15psi, key off
If under that cycle key on and off 3 times, should now show 30psi and then hold above 15psi

After engine is started, "running" fuel pressure should be 30-40psi
Raise RPMs to 2,000 or so, and hold it there, pressure should hold steady above 30psi, if its slowly dropping then fuel pump is weak or fuel filter is logged

3rd party fuel pumps are not as reliable as Motorcraft, but also cost 3 or 4 times less, lol, so.............
"New" 3rd party fuel pump doesn't mean much as far as diagnosing fuel pressure issue

If running pressure is not getting above 30psi then your Fuel Pressure Regulator(FPR) may be the problem
Its on the engine, there are two fuel lines that come into the engine bay from drivers side
Fuel IN, from the pump and filter
Fuel OUT, from the FPR

FPR looks like a small can, has a spring valve inside that holds pressure at 43psi max
If FPR valve fails system runs at lower pressure and/or can not hold pressure

 

[Iedector]

Tapping the key three times it maxes at about 17 psi. It never gets above 25.

Once I let off the key and it's not running, it builds up to about 23 or so.

 

[Dirtman]

Fuel filters are dirt cheap. I would replace that first and test again. Also pull the vacuum line off the FPR and smell for fuel. If it's still low it's probably time for a pump... But like I said spend the 10 bucks on a fuel filter first. If you do get a pump, do what @RonD said BUY MOTORCRAFT!

 

[alwaysFlOoReD]

I would suspect the pump.

 

[RonD]

The fuel pump is capable of 70psi at least

The FPR limits system to 43psi
If you have visegrips you can CAREFULLY squeeze the nylon OUT hose from FPR so fuel can't flow back to the tank
Don't want to CRUSH the hose and break it, just squeeze it
Then cycle key on and off, pressure should exceed 50psi easily
If not fuel pump is weak
If so fuel pump is OK and FPR is bad

You can also just disconnect the OUT hose from the FPR, put a towel down under the OUT port
Then cycle the key on and off
No fuel should come out of FPR port until pressure is above 40psi
If fuel comes out before that replace FPR
If pressure never gets to above 40psi then fuel pump is weak

 

[Iedector]

Thanks for all the insight. I'm going to go ahead and swap the fuel filter regardless.

I'm not quite sure I'm looking at the right part, with regards to the FPR. There is a small canister (engine front) on the fuel rail with a vacuum hose, is that it? I tried to follow the fuel lines from under the truck but they disappeared above the oil filter and it's such a cluster on the back of the motor that I can't see anything without removing the upper intake. I looked up a picture of the part and that seems to be it.

 

[Dirtman]

Yes fuel pressure regulator is on the fuel rail with a single vacuum line attached.

 

[RonD]

FPR will have two hoses, a vacuum hose and a fuel hose, and its bolted to the Fuel Rail, the part the fuel injectors are connected to

Now it can have a separate Return hose so just looks like there is only a vacuum hose attached
The fuel hoses in the engine bay should have steel mesh on them so silver color
There are 2, smaller one is the return hose from the FPR