1993 Ford F-150 93 F-150 No power

Tiny
LUMBEEINDIAN17
  • MEMBER
  • 1993 FORD F-150
  • 5.0L
  • V8
  • 4WD
  • AUTOMATIC
  • 190,000 MILES
1993 F150 has new plugs and wires. Cannot Rev over 3.5k rpm even in park no power going down the road. I can advance the timing and it gets a little better. Timing is set to 10 degrees currently. I'm getting code 172. Suggestions please.
Friday, October 30th, 2015 AT 1:35 PM

26 Replies

Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,004 POSTS
MY 1ST THOUGHT WAS, IS THE SPOUT WIRE PLUGGED UP FOR THE DISTRIBUTOR?

THEN I SAW THE CODE PART

THE CODE "P172" I BELIEVE, AND VERIFIED AS A TRANSMISSION CODE IN OBD I

THERE WAS NO EXPLANATION WITH IT

YOU MAY HAVE TO GO SEE THE TRANSMISSION WIZARD!

BUT FIRST, I'VE SEEN THIS TWICE BEFORE WITH OTHER FOLKS! CHECK YOUR FUSES FIRST BEFORE THE TRANNY GUY MAKES YOU FEEL REALLY DUMB!

I UNDERSTAND MANUALS PRETTY GOOD, AUTOMATICS ARE A WHOLE DIFFERENT ANIMAL, 'SPECIALLY THESE NEW COMPUTERIZED JOBS.

PS- I DID SCOUR OVER INFORMATION IN "PRODEMAND" FOR QUITE SOME TIME FOR BOTH TRANNYS THAT WERE AVAILABLE IN YOUR RIG, AND AOD AN E40D, I WAS UNABLE TO FIND ANY CODE INFORMATION/ EXPLANATION. SORRY!

THE MEDIC
Was this
answer
helpful?
Yes
No
-1
Friday, October 30th, 2015 AT 4:35 PM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
Transmission is in fact an E40D. I strated noticing a whistle from the engine bay today. Not sure that is related. I spared carb cleaner in the areas that look suspicious. But no luck. I also can't even Rev it over 3.5 in neutral or park just doesn't seem to have the juice. I'm going to test the Map sensor and also the egr sensor because I also ended up getting code 334 after checking again. I have a scanner to pull the codes for for OB1 l.
Was this
answer
helpful?
Yes
No
Friday, October 30th, 2015 AT 6:51 PM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
Spout connector is in and it does advance it as intended. I used a timing light to verify. It also can see that it advances a little more when I give it gas.
Was this
answer
helpful?
Yes
No
Friday, October 30th, 2015 AT 6:53 PM
Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,004 POSTS
2 MORE WAYS TO LOOK FOR A VACUUM LEAK

WET TOWEL AND A FIRE EXTINGUISHER HANDY (EVEN W/ CARB CLEANER)

OUT OF THE GARAGE AND NOT NEAR THE HOUSE, FOR SURE NO WHERE NEAR YOUR PRIZED JEEP CJ-7!

A PROPANE TORCH---NOT LIT!

NOT LIT!

NOT LIT!

WE JUST WANT THE GAS TO MAKE THE IDLE INCREASE BY GETTING THE GAS NEAR THE LEAK

METHOD 2

A 3-4 FOOT PIECE OF HEATER HOSE OR GARDEN HOSE, ONE END IN YOUR EAR, THE OTHER END LIKE A "HOVERING STETHOSCOPE"

THE NOISE YOU HEAR MAY VERY WELL BE A VACUUM LEAK, SEARCH WELL

BAD VACUUM LEAK!

BAD-BAD!

THE MEDIC
Was this
answer
helpful?
Yes
No
Friday, October 30th, 2015 AT 8:07 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
This is a different expert.

The 172 code means lean mixture on bank 1. I'm a little surprised you don't also have a 136 for bank 2.

These engines are notorious for the large vacuum connectors sucking a hole right through them that only opens up when the engine is running. Many times they are hidden under or behind the plenum where they can't be seen.

The easiest way to find this stuff is using a smoke machine pumping smoke into a vacuum line and looking for the leak,

Don't rule out that the 0/2 sensor may just be reading wrong also. You can monitor the 0/2 voltage while artificially enriching it to see if the sensor responds when it sees the rich m ixture.
Was this
answer
helpful?
Yes
No
Saturday, October 31st, 2015 AT 4:54 AM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
Sorry for the late reply. Been raining and a little busy. Last thing I done was test the MAP sensor. Either AutoZone sold me a bad one or I tested it incorrectly. I'm going to swap that for the new one. I tested the old one by first checking the reference voltage which was about 5.1 volts. Then I hooked a vacuum pump to it and tested the center lead which is supposed to go back to the computer and it read about 2.5 volts and it did not respond to vacuum. I'm putting that on tonight and then I'll try reading the voltage from the O2 sensor. Which wire am I looking at? I have 2 black 1 white and 1 grey.
Was this
answer
helpful?
Yes
No
Sunday, November 1st, 2015 AT 5:36 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
You can't test the MAP sensor that way. That sensor reads frequency in hertz, not voltage.
Was this
answer
helpful?
Yes
No
Sunday, November 1st, 2015 AT 5:50 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
https://www.2carpros.com/images/external/41929057.jpg.gif
Was this
answer
helpful?
Yes
No
Sunday, November 1st, 2015 AT 5:52 PM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
Do you think the O2 sensor could be getting a bad reading due to the fact that I have a large exhaust leak? If not feel free to give me a little more detail on how I go about testing that bad boy.
Was this
answer
helpful?
Yes
No
Sunday, November 1st, 2015 AT 7:25 PM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
Also I thought my year truck only had one O2 sensor. Which is towards the back in front of my muffler.
Was this
answer
helpful?
Yes
No
Sunday, November 1st, 2015 AT 7:27 PM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
I will try to test the Map sensor according to that diagram tommorrow. Just to give you an idea/update of the drive ability. When I'm going down the road with it and I'm lightly pressing the gas. It does pretty ok. As soon as I get down on it, it just roars and won't go anywhere.
Was this
answer
helpful?
Yes
No
Sunday, November 1st, 2015 AT 7:33 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
You also want to check for a plugged Converter.
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 1:59 AM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
I'm pretty sure the previous owner deleted the cats. How can you determine if a converter is plugged up or not? I was told they would glow red at night.
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 4:17 AM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
You were told wrong. You can use a pressure tester in the 0/2 hole. It should not exceed 2 PSI.

You could also just drop the exhaust and drive it.
If you have a vacuum gauge check the manifold vacuum at idle. It should be above 17". Then slowly bring the rpms up to 2000 and see if you have a dramatic loss of vacuum at that RPM
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 4:39 AM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
Sounds like a great idea. I will buy whatever tool I need to use to do those tests today. I just need a regular compression tester that you use for the cylinder for the O2 correct?
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 4:47 AM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
No, you need an exhaust pressure tester. Much lower scale.
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 4:59 AM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
I will buy or rent one today after 5 o'clock Eastern Time
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 5:39 AM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
After a visual inspection the only CAT I have on the truck is actually in front of my rear O2 sensor. Should I still test the pressure in the that 02 bank? Or do I have another O2 sensor somewhere that I missing?
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 7:48 AM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
Test at the sensor in FRONT of the Cat.
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 7:49 AM
Tiny
LUMBEEINDIAN17
  • MEMBER
  • 16 POSTS
I didn't know there was one in front of the CAT. Since I have LTH's does that make a difference here? If not I will get back to you when I'm able to do the tests.
Was this
answer
helpful?
Yes
No
Monday, November 2nd, 2015 AT 7:56 AM

Please login or register to post a reply.

Sponsored links