1994 problems.

[Rosie]

hi everyone, i tried searching the forums and stuff, just so much to read but not much on my specific problem.

first off some info, 1994 4.0 auto 4x4, 320,000 km's,

started up fine, warmed up, hit the highway doing about 55 mph, got about 5 miles from home engine loses all power, i drift to the shoulder and it stalls. engine light comes on.

it restarts, runs very bad, missing but no back firing. i can keep it running by being on the gas but if i try to let it idle it slowly stalls.

i limp it home, shut it off and let it cool down so i can do some trouble shooting.

checked plugs, wires, disconnected the battery.

plugs and wires looked fine, so i reconnected the battery and started it. started fine, idled good until i put it in drive, then it started idling bad again.

i tested all the plugs and 2 out of the 6 are sparking really low compared to the remaining 4. thought it would be plugs but i switched them around and the bad spark stayed with the same cylinder with different plugs.

and finally plug wires are fairly new.

what would cause bad spark on only 2 of the 6 cylinders outside of bad plugs and wires?

thanks in advance...

 

[Big Jim M]

Bad plugs or wires will cause missing and sputtering...but not what you have described. If there is only one coil on that engine, maybe that.. Maybe the spark controller box.
I'm betting on a fuel problem.. Maybe even a fuel filter.. But fuel is where I'd be looking. Maybe the fuel pressure regulator, Maybe the fuel pump. Ya just have to check it out.
Big JIm

 

[bronco_lou]

bad coil pack? Have you pulled any codes from the computer?

Louis

 

[modelageek]

hi everyone, i tried searching the forums and stuff, just so much to read but not much on my specific problem.

first off some info, 1994 4.0 auto 4x4, 320,000 km's,

started up fine, warmed up, hit the highway doing about 55 mph, got about 5 miles from home engine loses all power, i drift to the shoulder and it stalls. engine light comes on.

it restarts, runs very bad, missing but no back firing. i can keep it running by being on the gas but if i try to let it idle it slowly stalls.

i limp it home, shut it off and let it cool down so i can do some trouble shooting.

checked plugs, wires, disconnected the battery.

plugs and wires looked fine, so i reconnected the battery and started it. started fine, idled good until i put it in drive, then it started idling bad again.

i tested all the plugs and 2 out of the 6 are sparking really low compared to the remaining 4. thought it would be plugs but i switched them around and the bad spark stayed with the same cylinder with different plugs.

and finally plug wires are fairly new.

what would cause bad spark on only 2 of the 6 cylinders outside of bad plugs and wires?

thanks in advance...

I believe the cylinders are in pairs. 1/5, 2/6,3/4 if those correspond to your bad sparks i would suspect the coilpack and then the ICM

but i also tell everyone to change your fuel filter they do not get changed enough and can save you from burning out a pump

 

[Rosie]

thanks for the help guys, i cleaned the MAF and replaced the fuel filter didn't help. battery is disconnected now hoping to reset the computer and i have added some STP fuel injector cleaner.....

another symptom.....driving along, low power but able to creep up to highway speeds, every once in a while it starts to vibrate, feeling like a 5 speed if you start off in too high a gear if you know what i mean.

how do i check for codes?

next step is to test fuel pressure i guess....

thanks again, this site rocks....

cheers

 

[Rosie]

oh and low sparks is on 1 and 5....

 

[modelageek]

oh and low sparks is on 1 and 5....

i think you should be checking the coil pack.......then the icm.........my guess is the coil pack

 

[modelageek]

if you have a multimeter check the resistance between the 1 and 5 sockets on the coil pack you should have between 13k-15k........ I bet you don't

 

[Rosie]

if you have a multimeter check the resistance between the 1 and 5 sockets on the coil pack you should have between 13k-15k........ I bet you don't

you are 100% correct, i do not...it read OL, but 2-6 read 14.5k

so does that mean i need to change out that coil pack?

if so would you recommend going new or maybe a good used from a auto wrecker if it tests ok?

 

[modelageek]

you are 100% correct, i do not...it read OL, but 2-6 read 14.5k

so does that mean i need to change out that coil pack?

if so would you recommend going new or maybe a good used from a auto wrecker if it tests ok?

yup you need a coilpack........do what you have to if you can get one at JY cheap and it test out......give it a try.........everyone is different. if it was me i would just get a new one because i cant be bothered doing the jy thing.....

* i think the exploders have the same 4.0 up until about 97 right?..........a lot of exploders at the JY

 

[Rosie]

priced it out, just gonna buy a new one....thanks again for all your help..

 

[Rosie]

ok so now suddenly today it just died completely. started bucking, hesitating, jerking, rpms going up and down, then it died.wouldn't start, then it did but not idle couldn't get the rpm's up then die, and that was it...nothing but a dead truck.....

would this be the ICM?

 

[modelageek]

ok so now suddenly today it just died completely. started bucking, hesitating, jerking, rpms going up and down, then it died.wouldn't start, then it did but not idle couldn't get the rpm's up then die, and that was it...nothing but a dead truck.....

would this be the ICM?

did you replace the coilpack? if yes was it a new one?

 

[Rosie]

yep, replaced it with a brand new one.....

 

[modelageek]

yep, replaced it with a brand new one.....

it could be anything........spray starter fluid into the TB if it fires up it is probably a fuel issue..........or you can check for spark!...........maybe you should check the coil and make sure it did not go bad