2.3L ('83-'97) Help!! 88 ranger 2.3L

[reneg8d]

Hi Guys,

New here. Have a friends 88 ranger that has a fresh engine, .040 over bore, new exhaust valves and seats. Newish IAC and EGR. Has New injectors. New fuel pressure regulator and filter. The engine is dumping fuel into the intake. Runs but poorly, and fills the #2 intake runner with fuel.

I'm an ASE master tech with more years at this than I want to admit, but I'm stumped. I do have a new ecm, but haven't installed it yet. Any thought, suggestions, or even smart assed opinions welcome..

I've rebuilt lots of engines of all makes and never had an issue like this.

Steve

 

[rusty ol ranger]

Wonder if one of your new injectors is no good?

 

[Uncle Gump]

Man... there have been some stories with junk injectors.

New really means untested.

 

[Uncle Gump]

I also moved your post to the 2.3L forum.

 

[Kenny's B2]

I experienced similar on an 90's vintage Buick that the owner swapped engines. The oem ECM was retained, but wired incorrectly for the replacement engine. A constant 12v was being sent to one of the injectors... Causing it to remain open and duplicating the same symptoms you describe.
Probe the offending injector with your DMM and see if you have a pulse or solid supply voltage.

 

[reneg8d]

Ok, for the latest. I have replaced the Map sensor and TPS sensors. Still over fueling, barely idles and sometimes dies. Borrowed a scanner and checked. koeo- Have a code 31 and 67. koer- have bank 1 rich(no kidding) TPS out of range. I'm about to set this thing on fire here.. Any additional suggestions would be appreciated. Kenny's B2- Pretty sure ford supplies a constant 12 v to the injectors and grounds them to trigger.. 2 & 3 are wired together and 1 & 4 are also(Factory harness)

 

[alwaysFlOoReD]

@RonD

 

[RonD]

You have Batch fire fuel injection, so yes, in a 4 cylinder engine, 2 injectors are grounded by computer at the same time, so just 2 ground wires back to the computer
Yes, all 4 injectors get 12v key on

New FPR...............check its vacuum hose for gasoline, warranty it if gas is found

Do the Clear Flooded Engine test
Turn on key
Press gas pedal down to the floor and hold it down all the way
(0 RPMs + WOT,wide open throttle, tells computer to SHUT OFF fuel injectors, no ground pulse, this is in ALL fuel injection computers)
Try to start engine, should just crank and NOT fire
If it fires/starts then fuel IS leaking in

Codes are odd
31 - EVP - (O, R, M) EVP signal is/was out of range - EVP
EVR - (O, R, M) EVP signal is/was low - EVR
PFE - (O, R, M) PFE signal is/was low - PFE

Does your 1988 have an EGR valve?

67 - Park/Neutral circuit fault - PNP
Transmission Manual Lever Position (MLP) sensor circuit - Transmissions
(M) Intermittent Park Neutral Position (PNP) sensor fault - PNP

Do you have a manual or automatic?
Manuals never had a "neutral switch" in Rangers

I would open up the computer and have a look inside
The barrel Capacitors, usually 2 or 3, liked to leak after 25+ years and cause issues, easy to fix, under $5
Can cause odd codes and poor running

What were the other codes, for MAP, TPS and Rich?

 

[Shran]

I would try a different injector or have that one leak tested. Test the injector plugs with a noid light. Do they all pulse or does that one stay on?

I would avoid running it like that and cranking the engine over, you are going to wash the cylinder walls with gas and and up with low compression on that cylinder.

 

[Cole8222]

Hi Guys,

New here. Have a friends 88 ranger that has a fresh engine, .040 over bore, new exhaust valves and seats. Newish IAC and EGR. Has New injectors. New fuel pressure regulator and filter. The engine is dumping fuel into the intake. Runs but poorly, and fills the #2 intake runner with fuel.

I'm an ASE master tech with more years at this than I want to admit, but I'm stumped. I do have a new ecm, but haven't installed it yet. Any thought, suggestions, or even smart assed opinions welcome..

I've rebuilt lots of engines of all makes and never had an issue like this.

Steve

Just my back yard mechanic ideas. But I'd swap out stock injector for the one/ones you suspect. From there decide if it is an injector issue. After that check and clean injection connection points. From there I Wana say air system but if it only 1 injector dumping I doubt it. I'd check the pump and possible ECU issues. It's it's only one injector I Wana say it's faulty. Swap the after market injectors around too and see if it causes the same issue in another combustion chamber. Again I'm self taught so this could all be bs lol...

 

[reneg8d]

OK Guys, I still have this thing.. Still runs "pig rich" (not sure where that phrase came from) and poor idle/ lots of black smoke Have gone through the engine a second time, new rings, etc.. New lifters and rockers too. All sensors have been changed. Don't know if #2 intake runner is filling up again or not.. Have replace the injectors twice as well.. All sensors and ecm have been replaced along with fuel pump at owners request...

What voltage should I see at the TPS and MAP sensor with the key on? I checked the other day with it running and got 0v at the TPS... I can't find any reference material that tells me which wires are signal and reference...

I plan to disconnect the ecm and check the injector harness for a possible short to ground.

Oh, and only 12in vac also.. Timing belt is on correctly and timing is set at 10* btdc..

I refuse to let this thing beat me! I'll take all the ideas I can get...

Steve

88 Ranger 2.3 5spd 2wd

 

[reneg8d]

Anybody???

 

[RonD]

TPS won't be your issue but its a 5volt sensor like all the other sensors, powered by computer's 5v power supply
Top wire is the 5v
Center wire is return voltage to computer, "the signal"
Bottom wire is the ground

Center wire should be just under 1v throttle closed, 0.69v-0.99v is spec
At WOT(wide open) it should be 4.5v to 4.7v

TPS is there to give the computer a "heads up" when gas pedal is pressed down, it does the same job as the "accelerator pump" did on a carb
MAP sensor is not fast enough in reporting vacuum change in the intake, so if you were to "step on the gas" with no TPS hooked up there would be a hesitation or stumbling until MAP sensor reported the change in vacuum


MAP sensor signal is not a voltage, its a frequency, some Volt Meters can be set to read frequencies
MAP sensor frequencies seen here: https://www.aa1car.com/library/map_sensor_ford.gif

When you turn on the key the MAP sensor reads local barometric pressure, which it stores as 0 vacuum for this drive cycle
That gives it a reference point for the vacuum pressure

Unplug the MAP sensor and plug its vacuum hose, see if engine runs better


12" of vacuum is pretty bad, unless you live above 7,000ft elevation?
Vacuum is created by engines compression ratio and a closed throttle plate, AND the ability for air to get OUT of the engine, i.e. exhaust
If air can't get out then new air can't come in, so low vacuum

There are two ways for gasoline to get into a 1988 2.3l Ranger's engine
The fuel injectors and the FPR(fuel pressure regulator)

FPR has a vacuum hose attached, if FPR is leaking internally then extra gasoline is sucked into the intake, check that vacuum hose for signs of gasoline

1988 Rangers ran 35psi fuel pressure, the high pressure pump in the frame rail is capable of 70+psi pressure
The FPR is set for 43psi max, vacuum hose with engine running pulls that down to 30-35psi
If FPR is not working then injectors could see 60-70psi and when opened by computer they let in way too much fuel

O2 sensors only last 12 years, after that you get Rich running

Are you sure its fuel smoke and not oil?
12" of vacuum could mean rings are done so oil burning
Spark plug tips should tell the tail, brown is fuel, black is oil

 

[reneg8d]

Thanks for the reply!

Fuel pressure is 38 psi at idle. Regulator was replaced. Vac hose is dry

Unplugged the map. Slight change. Put a hand vac pump on the map & pulled 18in - no difference

Engine has fresh .040 rings

O2 was replaced.

Cat is now a test pipe

Plugs are black/soot covered. Black smoke from tail pipe

We are at 7200ft above sea level at my house....

CTS, ACT, TPS, and IAC were also replaced.

Timing is set to 10* BTDC

I'm about ready to order another PCM..

I've already hit it with my purse, the wife's purse, and prayed a lot.. This thing belongs to a good friend and she would like her truck back. I stuck my neck out and promised to get it right for her...

Any other ideas would be greatly appreciated..

Steve