Bronco 95 EFI 5.8L

[mcKoloum]

Hi there, i have a 95 bronco 5.8l EFI. it have about 171000 miles. It starts right up when it is cold but hard to start when warm and smell gas. I already change the starter, the battery, the ignition coil month ago. I also change the EGR valve, spark plugs, cap and rotor, Canister purge solenoide, PCV valve and check the temperature sensor (with an ohm meter) and it seems to be normal. Yesterday the check engine light start to bright!!! and today no light. I pull the code and here are the result:

- KOEO: 654 172

- KOER: 632

I bought the truck 3 years ago and it have 141000, i never change the O2 sensor, never change the gas filter...

I know it could come from a vacuum leak, and i check all the hose and they seem normal.

Before i change the EGR valve the idle speed was really low around 500rpm maybe, the old EGR had a hole and after i replaced it the idle was better 700-800 rpm, i guess it is normal.

If someone have any idea why it is hard to start, i need to press the gas pedal sometimes to help it start.

I also have a little knocking noise when under a load or when i need power, it always did that, i don't know how to fix that, apparently it could be a timing problem???

thank you everybody for your advice.

 

[miesk5]

yo,

Welcome to the Zone!

DTC 522 & 654 indicate the gear selector was not in Park during Self-Test; or Less Likely "...Possible causes: Misadjusted linkage. Open or short in harness circuits. Damaged TR sensor this is the (Manual Lever Position/Transmission Range (MLP/TR) Sensor located on the tranny). Damaged Powertrain Control Module (PCM)

Does your Bronco have the Mass Air Flow (MAF) sensor? if so,

DTC 172 lean Heated O2; "...Backprobe the MAF (+) and MAF-RTN (-) lines with a DVOM. You should see ~1.0V or slightly less at warm idle. If not, check the +12V and GND lines to make sure there's battery voltage between those terminals with the ignition key turned ON. You also may want to try using the proper spray cleaner on the MAF wires, especially if you have a K&N oily filter (in which case I can almost guarantee there's oily junk on your MAF's wires). Also make certain that the tube(s) leading from the MAF to the throttle body are 100% intact.

That diagram is a bit upside-down, really. Here's a picture that should help clarify

The red wire (on the right in the first above picture) is supposed to have battery voltage with the key on. Measure between that wire and the one right next to it. You measure the MAF voltage at idle, because the MAF voltage is what's interpreted by the PCM..."

Source: by SigEpBlue

Confirm the wiring w/ Wiring Diagram in a 95 (see#3) Source: by MR FIX-IT - our pal, Seabronc (Rosie, Fred W) at Ford Bronco Zone Forums

DTC 172 Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S

DTC 41, 42, 91, 92, 136, 137,139, 144, 171, 172, 173, 175, 176, 177 & some Possible Causes for Rich & Lean HEGO The engine temperature must be greater than 50°F (10°C) to pass the KOEO Self-Test and greater than 180°F (82°C) to pass the KOER Self-Test. To accomplish this, the engine should be at normal operating temperature Source: by Ryan M (Fireguy50) at fordfuelinjection.com

DTC 172, 173 or 41 for HO2S Failure, in POSSIBLE LOCATIONS OF WIRING SHORTS TSB 95-02-11 for 92-95 Bronco & F Series; "the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may be cut on the lower right engine mount causing improper signals to be sent to the PCM. Damage may be under the electrical tape..." SEE TSB 95-5-21 for Detailed Info Source: by Ford via Chilton

DTC 172, 173 or 41 for HO2S Failure Or Fuse "E" Inoperative, ABS Light On, Back-Up Lamps Inoperative, DRLs Inoperative, MIL On, Inadvertent Self-Test, Speedometer Inoperative & Trailer Battery Charge Relay Inoperative TSB 95-02-11 for 92-95 Bronco & F Series Source: by Ford via Chilton

632 ® E4OD - Transmission Control Switch (TCS) should be cycled once between engine ID and Goose test

DTC 632 - OD cancel switch not changing state. "...During the KOER test, AFTER the initial recognition code is generated, the brake pedal must be applied, the OD switch must be turned off and then back on and finally the "goose" test must be performed. This code is generated when the person performing the KOER test fails to deactivate and reactivate the OD cancel switch at the end of the shift lever. It does NOT indicate a problem unless the switch WAS INDEED deactivated and reactivated and the code still came up. (Computer needs to know if the tranny is in OD or not)..."

Source: by greystreak92

 

[mcKoloum]

Hi Miesk5,

Thank you very much, i appreciate.

Sorry for the late answer,

So no i don't have a MAF,

i have a MAP.

The light engine never came back on

wich is good.

But i still have to turn the key 2 times

and press the gas pedal and then smell gas.

I can feel the engine is not running normaly

when i drive around 30 mph, it is like the engine

have too much or not enough gas.

The idea about an injector who will stay open could be right,

now i don't know if that will make a hard start?

Thank you again for your input.

 

[miesk5]

yo,

ok, had to verify MAF becauase some were in CALIF equipped..

re: "i still have to turn the key 2 times"

when you turn Key to start, does the starter turn over?

If now, reach down and try to jiggle the switch by reaching down on column below dash nd moving the actuator to switch mechanism

from Ford EVTM; The Control Module (PCM) runs the pump{s} for one second when it receives an ignition- on signal. It also runs the pumps as long as it receives a PIP signal from the Hall-effect devices, it continues pump operation even after the key is released from START. If the PIP signals fall below 120RPM, the control module cuts off the signal to the fuel pump relay or the integrated relay control module. The pump will also run when the terminals of the fuel pump test connector are jumped. the Control module signals the pump when it receives a CRANK signal, and when the Control module gets PIP signals that the engine is running. the pump does not run if the PIP indicates the engine is not running even with ignition ON {except for that first one second}.

Map Sensor

Testing, Symptoms & Overview; "...a multimeter that can read frequency is normally required to check the sensor’s output. But you can also use an ordinary tachometer because a tach can display a frequency signal. Here’s the procedure: Connect the two jumper cables the same as before, (see diagram in site) attaching each end terminal on the sensor to its respective wire in the wiring connector. If you want to measure engine vacuum so you can correlate it to a specific frequency reading, connect a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose. Turn the ignition ON and note the initial reading. The reading on the tachometer should be about 454 to 464 at sea level, which corresponds to a frequency output of 152 to 155 Hz. Start the engine and check the reading again. If the MAP sensor is functioning properly, the reading should drop to about 290 to 330 on the tachometer, which corresponds to a frequency output of about 93 to 98 Hz. No change would indicate a defective sensor or leaky or plugged vacuum hose..." a vacuum gauge to a source of manifold vacuum on the engine, or tee the gauge into the MAP sensor hose.

Source: by wellsmfgcorp.com @ http://www.wellsmfgcorp.com/pdf/Counterpoint1_1.pdf

Testing, Symptoms & Overview; "...Surging, Rough idle, rich fuel condition, which may cause spark plug fouling,Detonation due to too much spark advance and a lean fuel ratio, loss of power and/or fuel economy due to ******** timing and an excessively rich fuel ratio, vacuum leak will reduce intake vacuum and cause the MAP sensor to indicate a higher than normal load on the engine. The computer will try to compensate by richening the fuel mixture and retarding timing -- which hurts fuel economy, performance and emissions..."

Source: by aa1car.com

Consider Ford Fuel Injection and Electronic Engine Control: How to Understand, Service and Modify, 1988-1993; & Ford Fuel Injection and Electronic Engine Control: How to Understand, Service, and Modify All Ford-Lincoln-Mercury Cars and Light Trucks, 1980 to 1987 by Charles Probst

avail @ BARNES & NOBLE, AMAZON, E BAY, ETC.