we have a 1989 f350 with the 7.5 L 460 EFI gasoline truck, was driving it loosing power and RPMS, finally shut off, now it wont start.

What we have done so far.

EGR valve and pipe
TPS
FPR
fuel pressures and compression are good
checked injectors for pulse, no pulse
changed ECM
Getting pulse, plugs getting wet
It tries to start but doesn't
we have Fuel, air, spark, still no start
Battery, starter, alternator good

i dont know what to do now

 

Bad PIP sensor or ICM.
Check your codes.

 

I have seen it before that the converter is plugged so bad it wouldn't even start. Disconnect the exhaust somewhere before it and try to start it. Another idea

 

sounds very familiar , sorry to read this ,, did it sit for awhile , is the vacuum line to the intake ok , "in back to the throttle body to the sensor on driver side fire wall ,, etc people here have the knowing of alot you will get er fixd

 

With wet spark plugs, the engine is flooded out.

Hold down the gas pedal wide open and turn key and crank it about 15 seconds MAX. If it tries to fire off, keep the pedal down during the 15 second crank. If engine does start and run release the key and alow the engine to clear it self out and pump the gas pedal to keep it from stalling.

After the 15 second crank do not turn key off but keep the pedal down and wait 20 seconds(alows the starter to cool down little). And try again. You may have to do this a few times to clear the flood out of the engine.

After the 5th try, turn off the key and let engine sit for about 10 to 20 minutes for starter motor to cool off. If after several tries and still no engine start(or trying to fire off) Then engine may have jumped timing or something else is wrong

 

Have you tried pulling the codes? Have you tried using starting fluid? If it doesn't start on starting fluid, you either have an ignition or timing issue.

 

OMG....it was a plugged converter.... WTF i have never seen this before! i have replaced every frigging part on this truck.....UGHHH FML

I did a lot of searching on the forums and never saw anyone with the plugged converter.

I couldnt believe how plugged the coverter was...so bad that the engine wouldnt run...

dang

thanks for the input guys

i hope the next poor sob with this problem comes across this forum

 

Glad you got it. I only seen it once where it wouldn't run at all. Just wanted to throw it out there as something try

 

So now you have to wonder what destroyed the converter. Rich mixture is worse than lean.

 

The nightmare is back and continues to haunt us.......OMG WHY.....

This truck has EVERYTHING NEW!!!!!!

Today it stalled out 10 times, and everytime you cylce the key to off and then crank, it starts up again.


The cat is completely empty (hollow)
New distributor (MSD)
New wires
New plugs
New ignition module (and yes we took it off and tested it 5 times)
New ECM from rock auto programmed
New fuel pressure sensor
New starter relay
New EGR valve and sensor
EGR pipe
TPS
FPR
fuel pressures and compression are good
Getting pulse at the injectors
Battery, starter, alternator good
New Coil

FML now i have to get a tow truck again, i could have bought a new truck at this point

 

I bet you are losing electrical power somewhere, could be corroded connections on the PCM or fuel pump relays, or a badly worn ignition switch. Lots of possibilities for dodgy wiring in a truck that old.

 

hmmm.....should we start taking apart electrical connections one at a time until we find a possible culprit for corrosion? We cant be the only one out there that has had this problem? there must be a common area/connector that causes this problem.

What do you guys think about changing the ignition switch, amongst all the parts changing, i dont believe that got changed.

 

you mentioned something odd, if you HAVE to cycle the switch off, then on for it to work, whereas a normal "just start the dang thing" wont work then you are doing something different - fuel pump prime. I suspect fuel pump drive system, relays, harnii, the dual tank switch, 1989 the fuel reservoir..check those out.

If a hi-pressure gauge hooked up to the fuel line drops off a lot when this dies, then that nails down the pump stopping...

 

Ok, i think we are going to run it with an auxiliary fuel pressure gauge and watch and see what it does when it stalls.

Someone also told us about an adjustment on the ignition switch?

 

A cheap code reader and Shop Manual would have saved you a lot of time and money...