My 89 F350 windsor 351 is so unreliable, I'm seriously thinking about having the junk man haul it away.

Doesn't start anymore, used to start like clockwork.

When it runs it just drops dead on acceleration. Randomly drops dead when idling. No CEL.

When warmed up it seems to run fine.

Is there a way to give this thing a complete lobotomy? I simply can't deal with this unreliability anymore. My main use of it is to drive barely a quarter mile to the fire station and back, which gives it no time to warm up. It always had a slight hesitation on acceleration but now just dies. My mechanic states, "This is about the time when the electronics on a truck of this age just start failing dramatically." I want to give it a new brain and not screw around with 15,000 sensors anymore.

It's going to the scrapper if there is not an easier solution to this problem.

 

Kind of the same situation with a 2006 F350 plow truck. Engine’s ok, needs some mechanical work, but slowly rusting away. Slam the door and a pound of rust falls off. Bed supports giving away. Worked it as long as I could. Not worth putting money into. Decided yesterday to get rid if it.

 

I feel kind of bad giving up. I like older cars and trucks, but there comes a point when you just can’t take it anymore. My 86 735 BMW went to the scrapper when tranny blew out. After 300,000 miles I figured it was time. The 89 F350 is a great truck, but I may have ignored it’s death moans for way too long. I’m too tired to keep trying CPR on the old guy.

 

Does not matter. There might be stored (or active) codes but not cause the light to come on.

Step 1: check codes.

 

Sounds kinda like an ECT sensor acting a fool.

But, I'm with "My4Ford" pull the codes. Might have a stored one that tells the story.

 

 

I'm with the others on trying to pull codes before giving up. It may be something relatively minor and cheap versus having to get another truck.

If all you are doing is just short runs on the truck it's hard on them. If you get it back up and running take it out and stretch its legs once in a while. Just don't pound he hell out of it right off. I bought a farm truck one time when the engine on my car grenaded on me, It was originally a State owned truck then they sold it at auction and it had been used on the farm, never ran at highway speeds for over 20 years and ran like total crap. (It was an 86 C10 with a 4.3 V6 and a 4bbl) I took my time and did an engine flush,seafoamed the engine,gave it a tune up and babied it for a thousand miles as i cleaned the fuel system and got the internals working properly, after a bit,the thing ran like a scalded dog and I put 100K miles on it in 4 years. Original odometer read 73K but there was no telling when it stopped working, I used a GPS to log the miles on it. I finally sold it when it blew a head gasket and a fella made me an offer I couldn't refuse. He repaired it and it is still running around town.

 

What is the ECT module?

 

it's not a module. It's a sensor. Engine coolant Temperature sensor. Should be located near the thermostat housing I believe. thats where mine was on my 4.9. I am not sure on the 351 if it is like it is on my 4.9 but the ECT sends the PCM info so it knows how to adjust the engine trim and the gauge on the dash is connected someplace else on the engine block getting it's temp reading from the water jacket.. two separate things

 

[QUOTE/]Engine coolant Temperature sensor[/QUOTE]

One of the first things I replaced. That and the air intake temp sensor. Fuel pressure is fine. Replaced the main brain. It fixed it last time. Not this time. I’ll pull codes again. There is a previous thread with the codes I got last time.

 

It’s most likely electrical, but it’s so intermittent it’s nearly impossible to diagnose. Given the cluster of baloney under the hood from the previous owner, it may be near impossible to track. It started with just randomly dieing when cold. Now it’s hard start, dieing on acceleration, and randomly dieing just because.

 

I’ve had a very similar problem before. My mechanic said, “beats the tar out of me.” I got a new brain and it ran fine for a couple years. Almost identical problems this time, but a new brain didn’t help. So that’s three brains in as many years. Replaced the two easy sensors this time, ect and air temp. I have a box full of engine relay, the thing on the distributor, throttle position sensor, and one other damn sensor I don’t remember at the moment.

People put crate motors in these things with all new ignition and everything else. They don’t use any of the stock baloney. My initial question was how to start bypassing the 30 year old crap that is obviously failing with third party equipment. I’m just super frustrated.

The engine is fine, but the stuff that runs the engine obviously is not.

 

If you want on Thursday I can drop off an LED light I made to test the PIP.
I was wondering how things where going when I drove past you're place last Thursday.

 

I believe there are 2 coolant temp sensors. One for the dash, and one for the computer. Someone correct me if I am wrong.

 

That's correct. The ECT should have 2 wires, and it talks to the computer. The other just controls the gauge.
I ran into this years ago, where my gauge worked fine but my computer thought the coolant was a complete different temperature. It really played hell with the truck, caused symptoms very similar to what the OP is describing. And it didn't throw any codes of course, because the computer just adjust to the indicated temperature from the faulty sensor.