Hey everyone, new, very frustrated member here.


inhave a 1988 e350 chassis with the 7.5 liter motorhome.


I bought it a few years ago and it's been great. About a year ago, it randomly stalled and would not restart during a camping trip. After about half an hour, it started up and ran fine. The two hours home. Did not do it again for quite some time. A few months ago it died on my street again. Headed toward to the shop and they said that it was losing spark. They replaced:



ignition coil and pigtail

ignition control module

lower column ignition switch

new distributor.


ran fine for a while, then the exact same thing happened. Took it to a different shop, and they replaced:


fuel pump

fuel filter


this morning, I was going to take it for a ride, and the exact same thing happened. Ran for about 10 minutes then sputtered out. When I go to restart it, it won't turn over. I tried it again and hammer on the gas and it'll start up and run funny but as soon as I let go of the gas, it'll die.


if I wait about 45 minutes, it'll start back up and run fine for a few weeks until it happens again.


The last shop said that the gas had some water in it and was pretty murky and for me to go ahead and get rid of the gas that's in it by letting it run for a while and then they will swap out the fuel filter once again once I put brand new gas in it.


please help! Every time it's in the shop they can never get it to mess up. It was in the shop for over a month and they could not get it to duplicate what it's done the last two days. Any ideas I am open, because the wife is asking me to sell it because it's not reliable. Any ideas?


thank you in advance for the help!

 

Does it ever do this at speed? . . . or is it always when stopped or moving really slow?

 

Always when I just start, and it will run from
anywhere from a minute to ten minutes then dies.

 

no. Randomly when I started it'll run for anywhere from a minute to 10 minutes and then die. I'll try and start it for about 30 minutes and it will not start. If I give it some gas it'll get going but the second I let off the gas it dies again.

After about 30 to 45 minutes, it'll just start right up and run perfectly.

It's never died when I'm moving or on the highway or roads. Strictly does it for the most part when it's idling or stopped, once at a stop sign, and the other times just idling in the driveway or at the campsite.

After about 30 to 45 minutes of trying to get it started, once it starts, it runs perfectly until I get home. I will shut it off and come back in about an hour and it'll start right back up and run perfectly.

Thank you in advance for your reply! I hope to get this thing fixed for a much longer trip in it.

 

When it dies, does it start to stumble, then get worse, then give up? . . . or does it just shut off in one quick step like turning off the ignition?

 

it does not feel like it would if it were to run out of gas and sputter and then die out. It seems to be running, and then just stop running. My old mechanic said that it may be losing spark after the distributor. I'm not sure if that helps. Once again, I appreciate your help.

 

Almost sounds like vapor lock. I presume this has fuel injection or is it carburetor? 1988 was first year for fuel injection I believe, and they have been known to have some quirks. Either way make sure fuel line is isolated away from heat source best as possible. If carbureted adding an electric fuel pump can help. One more thing is fuel pick-up in tank could be getting plugged from contaminates, then after sitting for a while contaminates fall off pick-up screen only to get sucked back up when running again...... and repeat.

 

correct, it is fuel injected. I just had the fuel
Pump replaced, got rid of all the old
gas and put new gas then changed the fuel filter again.

my mechanic is convinced its losing spark AFTER the distributed but he does not have a machine old enough to check for codes ( he deals with newer, diesel only)

 

If it just shuts off like the key was turned off it is loosing spark.
Now the ICM was replaced do you know if they went with a cheap one (I bet they did) or top of the line one?
You know "you get what you pay for" and we see the cheap ICM fail with in a year.
When they fail you get no spark till the box cools off in about an hour less if the hood is open.

It is also easy enough to check for spark, pull the wire out of the cap from the coil and hold it 1/4" from the motor.
If you cant see the spark you should be able to hear it "snap" at each spark.
WAIT the TFI unit is in the distributor on yours? I know later years the TFI was moved from the distributor to a heat sink somewhere in the engine bay.
You can try and put a bag of ice over the TFI to help cool it faster to see if that works.

In the truck area we tell members to buy top of the line ICM / TFI and use the thermal paste as it helps move heat from the ICM / TFI to the dist. or heat sink as that seams to fix the problem most of the time.
If not you now have a spar unit.

I would also get a EFI fuel PSI tester and run it somewhere you can see it and seer what happens.
The last thing that can be a issue is the computer. Between the age and the heat / cool it goes thru they are failing.
It is the caps inside that fail, they leak brown gunk and get bigger is size.
You can check out the 87> truck area as you have a F350 truck in a different wrapper, and post the problem there or just look over posts.
There is also a way to pull codes without a scanner I just dont know how that is done as I dont have a computer on my 81 F100.
Good luck and keep us posted
Dave ----

 

A lot of good input from @FuzzFace2 ^^^^^^^

I wonder, as a test, if you let it idle when it would normally die but have the hood open and a box fan or similar blowing air across the top of the engine. If it is easily reproducible, but doesn't reproduce while doing this, you're on a track to sorting it out.

 

this is the issue. Normally, I will start it and let it run. Few weeks ago it ran for almost 8 hours. I had to keep
gping out to see if it was still running, as it was running so good you couldn't even hear it idle.

i rolled the dice and took it camping about an hour away. Ran flawlessly. 2 days later, I pack up and get it ready to leave. Start it up, and it does 5 minutes in to idling. Took approx 30 mins to start back up, then ran flawless all the way home.

to say im frustrated. is an understatement.

 

thank you so much for your input! I will
ask my mechanic the brand of the ICM.

I wouldn't think heat is an issue, as all the times it has failed, was not during a trip, but in the very beginning, say 5-10 mins upon the first starting of the truck.