Need Help: Problem Diagnosis

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Oct 21, 2023 | 01:21 PM

jfruser

Thread Starter

Mountain Pass

Joined: Apr 2009

Posts: 131

Likes: 21

Need Help: Problem Diagnosis

We are having a bit of trouble diagnosing the issue with my sone's 1980 F-150.
1980 Ford F-150 Custom 2WD Single Cab Long Bed 150Kmi; I-6 300cid, 1bb Carter carb, Ford 3.03 3-spd man, Ford 9" 2.75 rear end, P235/75/R15,

Symptoms:

Turns over, but does not catch.
Compression was fine a short time ago, but now wonky.
Getting spark.
Getting fuel, fuel pump good.
Distributor spins.

Two WRONG diagnoses:

Catastrophic hunks-o-metal failure with pistons/crank/rods. We drained the oil and fished for metal with a magnet on a flexi-rod. Nothing found.
We thought maybe a bad timing gear, but taking off the timing gear cover, both gears are metal and look good and healthy, not in pieces like we suspected.
Rebuilt carb.

We are not sure what the issue is.

Oct 22, 2023 | 04:19 PM

FuzzFace2

FTE Legend

Joined: Nov 2015

Posts: 30,935

Likes: 4,123

From: Angier, NC

Quote:

Originally Posted by jfruser

Turns over, but does not catch.
If you put a little gas down the carb what happens?
Compression was fine a short time ago, but now wonky.
Wonky? Like how? Maybe use a different gauge to test again.
Getting spark.
Where and how was this tested? Pulled coil wire from cap to ground? Did you also check at a 2 or more plug wires?
Getting fuel, fuel pump good.
When the throttle is moved you see it squirt or you pulled the line off the pump to a bucket / jug?
Distributor spins.
With out skipping? If you pull #1 plug and finger over plug hole tap key to get compression and then line the timing marks up to TDC. Then pull cap and see if pointing to #1 on the cap tower.

Two WRONG diagnoses:

Catastrophic hunks-o-metal failure with pistons/crank/rods. We drained the oil and fished for metal with a magnet on a flexi-rod. Nothing found.
What made you think this did you hear bad noises and shut it off? Any metal you may find in the pan I dont think a magnet would pull in.
We thought maybe a bad timing gear, but taking off the timing gear cover, both gears are metal and look good and healthy, not in pieces like we suspected.
Good call if you found the timing marks or #1 on cap did not line up if you checked that first. If both gears were metal then someone was in this motor as only 1 is metal the other (cam) is fiber from the factory.
Rebuilt carb.
Did it need it or just pulling out straws?

We are not sure what the issue is.

You may want to post this up in the 80 - 86 truck area as a lot more people will see it up there.
When did this happen, little by little hard starting or shut it off last night and did this the next morning?

See my questions in RED
For S&G replace the ICM on the inner fender. It is cheap and worth having a spare behind the seat if just in case.
They have been known to do some strange stuff.
Dave ----