1988 2.9L Fuel Issues PLEASE HELP! Scratching head on this one!

[larams2380]

Ok after coming home from out of town work I have done the following and still scratching my head.....

1. Fuel pumps running constantly. Flooding spark plugs. Disconnected ECM to rule it out and ECM is good as fuel pumps keep running
2. Good spark
3. Firing order corrected
4. Power to injectors
5. Fuel pressure at rail at 40lbs
6. Will NOT start with starter fluid.

Could some sensor be at fault? I did replace the fuel pump relay and fuel pumps keep running any way. For some reason not getting pressure for the fuel system.

 

[RonD]

Fuel pump shouldn't run with key on engine off, well it comes on for 2 seconds, and thats all, so there is a problem there, ECU runs the fuel pump, so ECU is not "in the clear"

Pull out fuel pump relay, green one, and fuel pump should stay off
You can then try the 50/50 test, so engine can't "flood out"
If still a no start you have a spark issue, timing or too weak

If you show 40psi fuel pressure at the engine, then its not flooding out because fuel pump is on, there is a fuel pressure regulator(FPR) on the engine, has a fuel hose connected AND a vacuum line, check the vacuum line for gasoline, that could flood out the engine
FPR looks like a little "can"

 

[larams2380]

Fuel pump shouldn't run with key on engine off, well it comes on for 2 seconds, and thats all, so there is a problem there, ECU runs the fuel pump, so ECU is not "in the clear"

Pull out fuel pump relay, green one, and fuel pump should stay off
You can then try the 50/50 test, so engine can't "flood out"
If still a no start you have a spark issue, timing or too weak

If you show 40psi fuel pressure at the engine, then its not flooding out because fuel pump is on, there is a fuel pressure regulator(FPR) on the engine, has a fuel hose connected AND a vacuum line, check the vacuum line for gasoline, that could flood out the engine
FPR looks like a little "can"

Thank you RonD. Relay is good as when disconnected pumps shut off. FPR has no fuel at vacuum line.

When key in "on" position only and I unplug ECU pumps still run so I figured the capacitors are good in the ECU. If not flooding how are plugs getting soaked?

 

[RonD]

Fuel pump should NOT run with ECU disconnected, the relay wouldn't work

As said, disconnect fuel pump relay
crank engine over, with gas pedal to the floor, to dry out the engine
then do 50/50 test to see if you have good spark at the right time


Spark plug tips should be WET after cranking and a no start, doesn't always mean engine is flooding out, it can mean engine is getting gas but doesn't have enough spark or compression to ignite the gas
50/50 test will tell you if its a spark or too much fuel issue

 

[larams2380]

Correct. Fuel pumps run with ecu disconnected and key in on position.
Will do 50/50 test but I do know I have good spark. May get a light tester and test timing. Sounds like it wants to start but when turning key to off it gives a puh puh sound

 

[RonD]

"Correct. Fuel pumps run with ecu disconnected and key in on position."

Fuels pumps SHOULD NOT RUN with ECU disconnected, someone has hot wired the fuel pumps to come on with key on
May be by grounding fuel pump relay
Do pumps go off when you pull out the fuel pump relay?

 

[larams2380]

"Correct. Fuel pumps run with ecu disconnected and key in on position."

Fuels pumps SHOULD NOT RUN with ECU disconnected, someone has hot wired the fuel pumps to come on with key on
May be by grounding fuel pump relay
Do pumps go off when you pull out the fuel pump relay?

Yes pumps off with relay out

 

[RonD]

Leave relay out and redo 50/50 test(manually add fuel to engine) and see if engine starts up, if not then spark is not working or out of time
This is the ONLY WAY to test spark on a fuel injected engine, well any engine really, lol

 

[larams2380]

Leave relay out and redo 50/50 test(manually add fuel to engine) and see if engine starts up, if not then spark is not working or out of time
This is the ONLY WAY to test spark on a fuel injected engine, well any engine really, lol

I am not understanding how this addressess the fuel pumps continually running? I will do the 50/50 but it won't fix the pumps. could the fuel filter be the culprit? Your input is MUCH appreciated!

 

[RonD]

You are testing if it is "a fuel pump problem", i.e. engine is flooding out

Previous owner may have "hot wired" fuel pump, which in itself causes no running issues, just a safety concern if there is an accident
Fuel pump being on all the time, with key on, will NOT flood a fuel injected engine, as thats is normal state if engine is running

 

[larams2380]

You are testing if it is "a fuel pump problem", i.e. engine is flooding out

Previous owner may have "hot wired" fuel pump, which in itself causes no running issues, just a safety concern if there is an accident
Fuel pump being on all the time, with key on, will NOT flood a fuel injected engine, as thats is normal state if engine is running

yea it is strange. 40 lbs pressure at the rail and sounds like gas is returning to tank. I do not recall the pumps running all the time when I bought the truck but then again was not listening for it. Will run the tests and keep you posted. if it was indeed hot wired would it bypass the relay?

 

[RonD]

Most common method is to use a Jumper on the OBD1 connector in the engine bay to ground the Fuel Pump Relay full time

Bypassing the relay would require a fused Key On 12v source, which could be done but not easily, the fuel pump's fuse/fusible link has 12v all the time so couldn't be used

 

[larams2380]

I have a neighbor that feels the motor was rebuilt and whoever put it back together put the distributor in 180 degrees and changed the firing order at the same time. In replacing the plug wires I followed the correct firing order which equals no start. Hoping he fixes it this week and will post if this is indeed the issue. Thanks again to you all for your time and input!

 

[RonD]

That is certainly possible and before engine computers a practical application of your brain, lol

But TFI distributor does have a #1 TDC vane window in distributor, slightly wider or narrower, can't remember, but doesn't matter, just the part that #1 is IDed in rotation matters
This was only needed for sequential fuel injection which most Rangers didn't get until 1995 and the newer EEC-V computers using crank AND Cam sensor

1986 thru 1992 2.9l used batch fire injection so the cap wires can have #1 starting anywhere and firing order would progress from there in clockwise direction

 

[larams2380]

IT WAS ME! had firing order off one hole and that was the entire issue! cannot trust myself and must double check work before hiring out...thanks all!