hello everyone and Happy Holidays!

I recently traded a dogged-out 89 Ranger 4cylinder for a 1988 F-350 (great trade!)
that has a 351 engine, auto tranny, dual tanks, approx 180,000 miles.

Have been using the big f-350 to sell firewood as it can hold about a cord and a half ( it has a steel 8' x 8' flatbed ). when I got it I changed the oil, filter, air filter, and fuel filter.
after approx 3,000 miles the oil is still clear (wow), and the engine is quite strong.

yesterday. and sometimes, it has a sputtering problem while on the gas pedal, not at idle.
this morning it started fine, a few miles later it started sputtering so I went to rev it up and the motor stalled.
from that point on it will not start. motor turns over, its getting spark, and I removed the fuel filter and turned on the fuel pump and it works great.
only thing I noticed was that the gas that came out was kind of brownish??
I regularly run about 5-8 gallons of gas through it everyday so I dont think there could be water in it and have two tanks and put fresh gas in back tank, still wont start at all.

The sputtering is only issue it had before this happened...

Any ideas what it could be?
Note, I am a mechanic of sorts and have always owned f-series trucks so am familiar with most problems but this one has me stumped....

I guess I should see if there are any codes?
How would I get the codes? use a jumper wire?
and where to look up the codes it gives me? I don't have a manual....
assuming it may be a TFI or something similar?

thanks for your time!

 

water in the fuel maybe?? have you always used both tanks?? Might have gotten a real bad batch of fuel.... it shouldn't be brownish

 

thats what I was wondering....

also should mention that someone in my neighborhood has been stealing gas and coincidentally my sister-in-law said this morning that she saw a small light near my truck early this morning but whoever it was left before she could see anything...

however, as I said it started sputtering after I stopped at a BP gas station with a 1.5 cord load of firewood on it...so maybe I did get bad gas.

I am going to try to use starter fluid or something? to try to see if it will start or at least try to, off of that...if it tries to start then its bad gas or something to do with the fuel system?

also, I can't seem to figure out the EEC test connector which is under the drivers side hood, near fender.
it doesn't look like any of the diagrams or pictures so dont know how to hook up a jumper wire....any help appreciated on that

 

I have so far concluded it is getting no spark at all!

well I have replaced the spark plug wires, cap&rotor and the often broken Ignition Module

Still no spark!

so whats left?
the coil and distributor pickup?

what else could it be?

 

pull the distr. cap off and turn the engine over and watch the rotor,,make sure the rotor spins,... might have a broken timing chain... then get a book and test all the components.. when I worked for a local Exxon shop, before the owner would let us replace anything he wanted to see how we tested what we were replacing. I learned a lot... alldata was my friend..

 

thanks hemieater!

I have this spark plug tester that you hook to the coil wire at the distributor and the other end grounded on block bolt, it sayss it works with TFI-IV Ford ignitions and doing that I get absolutely no spark.

I really thought it would be the ignition module as they have a bad rep...

will check the components and timing chain...
thx

 

Making sure the rotor spins is just a quick and easy way to eliminate the chain... If the rotor spins then you can move on to the next possible cause... I have a few distr. kicking around just for this reason, Plug a known good one into your harness and spin it with your fingers... if it works you will hear it...

 

ok the rotor spins...whew!

so that means its the coil, or distributor pickup, or maybe the ECM? IDK

I dont believe it will kick out codes for the coil right?
have to use a multimeter right?
I just got a Haynes manual for this truck and will be doing the step by step diagnoses for all ignition components...

thanks

 

OK I think I am suspecting the coil...
I did the voltage check on coil and the test light lit up and blinked etc when cranking but NO spark at coil wire!

according to manual it may be faulty coil...will now try coil resistance tests which hopefully verifies coil is bad!

isnt it very rare for a coil to go bad?

 

the tests of the coil are confusing...

I tested the primary resistance, which should be between 0.30-1.0 and it's like 2.91 or something? but the manual says if it is BELOW 0.40 replace it, but it's above 1.0 ??

secondary resistance should be 3,000-11,500 and it's like 2,000

the other problem is the self-test check engine light test isn't working for some reason, maybe a bad computer?
i dont know
thanks

 

We can mark this thread solved!!

It was the ignition coil!
I believe what happened is that hauling all that wood with bad plugs and wires caused the coil to exert extra voltage to the plugs/wires to jump the enlarged gaps and rounded electrodes.
This resulted in a overheated coil which damaged it I guess?
Or it was just very old...

anyway, thanks alot HemiEater for all your help!