interemitant miss

[gillj]

Let me start by saying that I love the sight both Mrjim.net and NPORA

My name is Jason I have a 91 Pathy 4x4 manual V6

And I love this truck its very capable never got stuck yet while I’ve been out playing in it

Im not a member of the NPORA as of yet but im going to join soon as I get pics of

My truck

I do have a few questions for you or anybody out there

My truck has an intermitant miss or something I cant figure it out

That just started about two weeks ago

Sometimes it will start and run fine and smooth for a while than start sputtering

And missing or something and sometimes it does it all the time

ive replaced fuel and air filters fuel pump new plugs checked resistance on plug wires

distributor seems fine im getting strong spark at all wires

Ran all my codes and nothing seems to be showing up im open for any suggestions

Is it likely that it’s the ECU itself or what

Please help

Thank you. And I do plan to join NPORA very soon

getting very frustrated :furious:

 

Jason.gill@med.va.gov

[87pathy]

did you replace the rotor as well?

 

did you check the gap on the new plugs before installing them?

 

if so, possible MAF sensor

it sounds like a spark issue to me though

[94extreme]

in the dark: lift the hood, start the truck, if you see a lightshow then the wires (or wherever the light comes from) is your problem.. could be crossed or cracked wires... could be the gap or the wrong spark plug, dirty dizzy cap will do it too.. vac line loose.. there could be a million things making it stumble.

[gillj]

guys i tried everything that you suggested allready

but i may have figured it out i hope so anyway

 

I unpluged the o2 sensor and drove it in mode #5 on the

ecu last night for awhile

and last night and so far all day today its been running good

and come to think of it it was acting like it was flooding out

god i hope thats what it is anyway

strange thing is I wasnt getting a code for O2 sensor

so i geuss only time will tell

 

does anyone know

When you put it in mode #5 does the ECU not monitor the O2 sensor at that time

[94extreme]

it must not be monitoring other thing either.. bad o2 seems to affect the truck differently then you described.. get a new o2 and see if that does help.. your mpgs may drop if you run without the o2 sensor functioning..

[gillj]

i figured the mpg would drop

but until i get the 150.00 for the new O2 sensor

it will have to work

at least i wont be sputtering and shaking down the rode

any more info on exactly how the ecu works could be helpful

[94extreme]

shop around. i got my o2 sensor for under U$40.

[gillj]

geuss what its still giving me trouble

could it be coil or distr it self would that come and go

and is there a way to test these if it was the ign control module it would just not run right?

any other suggestions

[Guest hjc]

Hi when in mode 5 ,at idle you should get no codes, try getting the rps to 2000 while in mode 5 if you get steady blinks its the crank angle sensor. I to have a 91 and it sounds alot like the proublem i just fix.Change the distributor and she runs like new,they are exspensive but i located one on ebay for 30.00 bucks. You can read my posts for my problem under runs rough when up to temp.

[gillj]

ill try that

but mine has the miss when it wants to and at any temp

[gillj]

when i say it wants to i mean at different times and with no other apparent causes just comes and goes whan it feels like it

all speeds all temps no matter what ive done so far even at idle

 

i will try what you suggest HJC

is there any way to test the distributor

[Guest hjc]

hey, got all my info out of a service manuall for the 91, book is right out of the shop. there is no test for the distributor but the crank angle sensor is in the distibutor. mark the postion of the rotor and pull the distributor. when out leave power hooked up and spin the gears slow. you should hear the injectors opening. my shaft had a small amount of play in it . Like i said in mode 5 at idle you should get no codes,but in the service manuall it said to rev rpms to 2000 this is when i got the code for the crank angle sensor.when i started my post it only happened when she got to temp.but got worse as the day went by.if you want to talk email your # to punkin0823@cox.net

[gillj]

I think i might have figured it out guys

ive narrowed it down to cylinder#2 and its getting strong spark all the way to the plug so its either a sticking valve or injector

hopefully its the injector I guess ill find out as soon as i pull the injector out and check it

thanks everyone ill lett everyone know soon what it was