No power under load

LeBronCo

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I was looking to connect with Miesk5. In another post from Smafugula you noted a link for codes and a guy named Gary that had tons of info on the 2.9L FI motor. I've been chasing down a gremlin in my 87 xlt. Starts fine, idles fine, revs fine. Under load, like taking a small hill will not power up. Can barely make it in 2nd gear. New fuel tank, pumps, filters. New plugs, wires, timing, ECM, back pressure tested. Vacuum lines good ???

LeBronCo
 

LeBronCo

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Yo LeBronCo,
Welcome!
Did you mean a 4.9 (300 cubic inch) six cylinder?
If so, see Gary Marshall's site on the 4.9 @ https://www.garysgaragemahal.com/300-six1.html

If you 87 a full size Bronco?

Will be back tomorrow.
Al
Yo Miesk5,
Thank you. I mean a Bronco II w/2.9L V6. I've been chasing the gremlin for over a month now with no solution. Very frustrating to see this thing just sitting there. If you know of someone who is knowledgeable re: what makes this motor tick, ie: intake/spark/fuel/control, I'd be thrilled.
Nelson aka LeBronCo
 

miesk5

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Yo Nelson,
Some 2.9 info sources:
For a FORD 1987 Car & Truck Engine/Emissions Diagnosis Update--Drivability Reference Handbook
See https://www.faxonautoliterature.com...agnosis-Update-Drivability-Reference-Handbook
Excerpts;
"The driveability symptoms section contains indexes to the bulletins, OASIS messages, and recall information related to the following issues: hard/no start, idles rough/rolling, acceleration hesitant/stumbling, lack/loss of power, surging, stalling, deceleration stall/trailer hitching, spark knock/shutdown (diesels), runs rough/misfire/backfire, and flooding/fuel--exhaust odor/fuel economy. You’ll find diagnostic routines that identify likely causes of these symptoms in order of probability. You then use the diagnosis flow charts in the book to 1) identify a symptom 2) run a test and then 3) choose what to do next on the chart based on the outcome of your test. Some of the tests you can easily do yourself, while others require diagnostic equipment to identify trouble codes. You will find the actual technical service bulletins with updated repair instructions ..."
You must be registered for see images attach


2.9 Overview, but no Troubleshooting @
https://www.therangerstation.com/tech/ford-ranger-2-9l-v-6-engines/
 

LeBronCo

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Already a member of TRS and the Bronco Corral. Neither have been able to add to what I have done already. I'm so bummed because other than it not running right, the interior, exterior and suspension are perfect 9.5/10. The last mechanic said even though the compression test resulted in 185 psi across the board, the leakdown test was horrible and that the motor is worn out. Weird that a worn motor starts up first crank even when cold, idles nicely and revs nicely.??? Under load it will not generate power above 2K rpm and will struggle getting up small hills. Sometimes in 2nd gear. New distributor, cap, rotor, plugs, wires. New Map, TPS, ECM, fuel tank, both pumps and filters. All vacuum is tight. Am I missing something here?
 

miesk5

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Yo Nelson,
Did you check for Diagnostic Trouble Codes?

"Cylinder Leakage Detector​

When a cylinder produces a low reading, the use of Rotunda Pressurization Kit 014-00705 or equivalent will be helpful in pinpointing the exact cause.

The leakage detector is inserted in the spark plug hole, the piston is brought up to top dead center on the compression ******* and compressed air is admitted.

Once the combustion chamber is pressurized, a special gauge will read the percentage of leakage. Leakage exceeding 20 percent is considered excessive.

While the air pressure is retained in the cylinder, listen for the hiss of escaping air. A leak by the intake valve (6507) will be audible in the throttle body (9E926). A leak by the exhaust valve (6505) can be heard at the tail pipe. Leakage past the rings will be audible at the positive crankcase ventilation (PCV) connection. If air is passing through a blown gasket to an adjacent cylinder, the noise will be evident at the spark plug hole of the cylinder into which the air is leaking. Cracks in the cylinder block (6010), or gasket leakage into the cooling system may be detected by a stream of bubbles in the radiator (8005)."
by Ford
 

LeBronCo

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Yo Nelson,
Did you check for Diagnostic Trouble Codes?

"Cylinder Leakage Detector​

When a cylinder produces a low reading, the use of Rotunda Pressurization Kit 014-00705 or equivalent will be helpful in pinpointing the exact cause.

The leakage detector is inserted in the spark plug hole, the piston is brought up to top dead center on the compression ******* and compressed air is admitted.

Once the combustion chamber is pressurized, a special gauge will read the percentage of leakage. Leakage exceeding 20 percent is considered excessive.

While the air pressure is retained in the cylinder, listen for the hiss of escaping air. A leak by the intake valve (6507) will be audible in the throttle body (9E926). A leak by the exhaust valve (6505) can be heard at the tail pipe. Leakage past the rings will be audible at the positive crankcase ventilation (PCV) connection. If air is passing through a blown gasket to an adjacent cylinder, the noise will be evident at the spark plug hole of the cylinder into which the air is leaking. Cracks in the cylinder block (6010), or gasket leakage into the cooling system may be detected by a stream of bubbles in the radiator (8005)."
by Ford
Leakage was 40%
 

Tiha

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Okay, how about a different approach.
Are you sure the linkage is pulling the butterfly all the way open when mashing the pedal to the floor?

When trying to climb these hills, I assume you have the pedal all the way to the floor?
When you have the pedal all the way to the floor and the engine is struggling does it ever backfire? Pop back through the intake? Cough?
Or just seem to run along fine, nice and smooth?
 

LeBronCo

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Okay, how about a different approach.
Are you sure the linkage is pulling the butterfly all the way open when mashing the pedal to the floor?

When trying to climb these hills, I assume you have the pedal all the way to the floor?
When you have the pedal all the way to the floor and the engine is struggling does it ever backfire? Pop back through the intake? Cough?
Or just seem to run along fine, nice and smooth?
No pop or backfire. Just struggles. It feels like someone placed a governor on it.
 

miesk5

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Yo,
Try this Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19 @ Code Reader
EEC AKA PCM, computer stores the Self-Test program in permanent memory. When activated, Self-Test checks the EEC system by testing memory integrity and processing capability, and verifies that various sensors and actuators are connected and operating properly.
The EEC will tell you what it found out by testing your sensors, and also any stored information it saved from anything that went wrong during the last 40 trips.

Inspect the air cleaner and inlet ducting. Check all engine vacuum hoses for damage, leaks, cracks, blockage, proper routing, etc. Check EEC system including the wiring harness for proper connections, bent or broken pins, corrosion, loose wires, proper routing, etc. Check the Powertrain Control Module (PCM), sensors and actuators for physical damage. TPS, ICM, DISTRIBUTOR, etc. Check the engine coolant for proper level and mixture. Check the transmission fluid & engine oil level and quality. Make all necessary repairs before continuing with SELF TEST.

The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test. Run it around to heat the engine up and shift thru all gears including Reverse. Make sure A/C is off and transmission is in Park (automatic); or in Neutral for a Manual & release clutch. Then turn off engine, all accessories/lights (close driver's door) , etc.

Do KOEO test First. Post Code(s) here according to KOEO & KOER.
A helper can assist you by counting the codes. Some use their smart phones to record them.

BEWARE OF FAN, BELTS, PULLEYS, HOT HOSES, IGNITION HIGH TENSION WIRES, AND ENGINE COMPONENTS

Or ask local mom and dad parts stores if they will test it for you.
Or purchase a coder reader such as Equus 3145 Innova OBD 1 Code Reader for Ford EEC IV Engines at Walmart & most parts stores.
 

Tiha

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If the engine is not backfiring with the throttle wide open then the air/fuel ratio must be close to correct.

I would probably put a volt meter on the TPS and manually operate the throttle full sweep to make sure it is telling the computer it is wide open.
 

LeBronCo

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Thanks guys, Looks like I have some work to do. I'll get back to you when I've completed your suggestions. Thank you for your help.
Nelson aka LeBronCo
 

miesk5

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Yo Nelson,
Have you tested for Diagnostic Trouble Codes?

Some more info for you;
You must be registered for see images attach


With No Diagnostic Trouble Codes, see Table 12

Skip Scope to save $
Self Test is the Self-Test for Diagnostic Trouble Codes
 

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LeBronCo

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Miesk5,
Thank you for being so generous with your time. What do you think about Johnnyreb's post about replacing the timing chain?
Nelson aka LeBronCo
 

johnnyreb

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Miesk5,
Thank you for being so generous with your time. What do you think about Johnnyreb's post about replacing the timing chain?
Nelson aka LeBronCo
Well you can check the timeing chain without taking it apart. Put it on number 1.Notice the button. Mark it. The slowly move it back and see how much--if the button has moved.
 

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