I'm helping a friend with a full size Dodge van with a 360 in it. The van
will run very rough - dropped cylinders, after it's been running a while.
He has put a cap, rotor, wires, plugs in it, and the other day we he threw
some injector cleaner in it. The van ran much smoother after add the
cleaner, but the next day it was back to dropping cylinders.
What lead us to throw the fuel injector cleaner in the vehicle was that we
could unplug injectors and not affect the running of the engine, on several
cylinders. After adding the cleaner the engine smoothed out quite nicely.
Next day - rough running again.
He has strong spark on all 8.
I'm looking for ideas since I'm not familiar with this engine. I'm curious
how many fuel filters there are in this system. Where is the fuel filter(s)
We'll welcome any ideas.
You mention nothing about finding a fault code in the computers memory. I
hope you checked before you started unhooking things because now you just
put alot of codes in it.
Have you check EGR? disconnect the vacuum line to it, see if you have any
vacuum at idle.
No, unfortunately we did not check codes. Have no access to a scan tool and
the van has no CEL with which to flash the codes. I don't know if the bulb
is removed, or burnt out or if there never was one on this van (doubtful).
Have not checked the EGR yet. Will check it the next time he brings it
The behavior of this van is quite puzzling. I have not seen the symptoms
much myself, but am going on the stories by the owner. He claims it ran
great yesterday after putting the FI cleaner in the tank, but this morning
it was back to running like it was only firing on 5 cylinders. He stopped
at the gas station, filled it with gas and when he started the van again, it
was running fine. He did come over to my house with it, but it was purring
like a kitten all the while he was here. He shut it off for a while and
when he started it again it was still as smooth as you would expect. He
says that over the past couple of weeks he's thrown two containers of dry
gas in the tank, and two containers of FI cleaner. Seems doubtful that it
could be a water/ice problem at this point, but it sure does act line one.
Well Mike, key on before a start does a bulb test on all dash warning lites
including check engine lite. And you can check codes without a scan tool by
cycling the key. Do a google on how to check fault codes on this vehicle.
Keep in mind that whatever you find may be a clue to the problem or just the
results of you disconnecting things with the key on.
check this site http://www.allpar.com/fix/computer-codes.html
That's what I tried to do today when he brought the van over. No CEL light
ever comes on. Like I said - don't know if the bulb was removed or if it's
burned out. Hard to count the flashes this way.
Take it to an auto parts store that has a scanner and have them read out any
codes, my suggestion is to disconnect battery and let sit for 5 min to clear
any faults, then drive the vehicle for a couple days before having codes
read. That way you will know if they are new codes and not ones you may have
set by tinkering with it
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