very bad miss

NecroWolf

NecroWolf

lost marbles member
for some reason my truck has got a terrible miss in it. i put my tune up kit in about three weeks ago. black beauty wires, cap/rotor and ngk ur5 plugs. it's been raining really hard recently for a couple days and that was when it started. so i figured i had a plug wire looseor cracked a ceramic. nope check them all good and tight. so i figured i'd cracked the cap while i was putting it in. nope didn't see any cracks. the contacts were kinda green inside the cap and seem to be pushed out away from the rotor. so i pushed them back in a little. didn't really notice any change. so i thought maybe my thermo went bad and was keeping the engine too cold in the rain. replaced it, no change. pulled one back of plugs tonight, all i had time for and they looked pretty good. don't have data master and don't know anyone aruond with it. it's not tripping any check engine lights either. truck is going through gas like water. anyone got any ideas? is there any way to check the temp sending unit that goes to the computer without just replacing it? i know if those go bad and send an ultra low temp to the computer it'll run pig rich and cough and sputter. i'm gonna pull the other bank of plug tommorrow, maybe during lunch
 
VermontTy

VermontTy

Support Our Troops
Re: very bad miss

DM will tell you what the temp sensor for the computer is. Did you make sure the gap on the plugs was 0.035"? You said the contacts are already corroded and green and its been installed for just 3 weeks, and that you can move them by hand to move them closer to the rotor? Something just doesn't sound cool with that at all. Are the contacts on the cap aluminum or brass?
 
NecroWolf

NecroWolf

lost marbles member
Re: very bad miss

i believe the contacts are brass. i used a screwdriver and set them all the same. i think i should light it on fire and roll it down a long hill
 
VermontTy

VermontTy

Support Our Troops
Re: very bad miss

BAH! That's no way to be! Trust me, I fought through the ignition issue from hell the last 2 weeks only to find that I was unplugging the wrong damn "tan wire" to set the timing. DUH!

If I were you, I'd spend the $0.99 at any local parts store, and get a gap tool; one that looks like a quarter will work just fine. Weird things can happen from having too little or too much gap. The screwdriver approach might work on a Briggs & Stratton rototiller, not your Ty.

You replaced the ignition stuff. That should help you run better. The cap still sketches me out though. You replaced wires, cap, rotor and plugs and it ran worse. If the rotor was bad, it wouldn't run at all. If the cap was bad (which it may be), it would probably run on less than 6 cylinders (if you have an inductive timing light, clip onto each plug wire while it idles and look for flash to make sure all are firing). If so, its probably not the cap. If they are all firing with the timing light, it's not the wires, and that leaves the plugs, unless you unplugged something, or knocked off a vacuum line somewhere. Pull the plugs and gap them to 0.035" for starters and see where that gets you. It'll cost a dollar and a half hour.
 
NecroWolf

NecroWolf

lost marbles member
Re: very bad miss

yeah i plan on doing the vacum lines, money's always the issue though. i don't mean i set the plug gaps with a screwdriver, i adjusted the contacts on the cap. i might be slow but not that slow. i have a good gapper, and set all the plugs to right at .35. what got me is that it didn't start till the heavy ran came. i'll try to get my hands on a timing light over the weekend to see if that gives me any clues. i'm almost positive i got a vacum leak. when i change the thermostat the water that pooled on the intake got sucked up into my engine and it was smoking like a bad head gasket for a minute. that was either my injector o-rings or my intake gasket. i still pull almost 19" of vacum. or was, i haven't put the gauge on it yet. i guess i'll be taking tools to work tommorrow since they like to make us sit around for a couple hours doing nothing but waiting.
 
NecroWolf

NecroWolf

lost marbles member
Re: very bad miss

i did the tune up 3 weeks ago and it ran great but this week in all the rain it's been missing and jumping like i dropped a cylinder or something
 
SeattleSy#1255

SeattleSy#1255

Category 5 Conservative
Re: very bad miss

do the vacuum lines then come back...its probably the cheapest fix you can do on these trucks. Espically when you say yourself you think its a vacuum leak.
 
midnightbluS10

midnightbluS10

Banned
Re: very bad miss

VermontTy said:
If I were you, I'd spend the $0.99 at any local parts store, and get a gap tool; one that looks like a quarter will work just fine. Weird things can happen from having too little or too much gap. The screwdriver approach might work on a Briggs & Stratton rototiller, not your Ty.
Click to expand...

The .99 piece isn't any better. I've always used a feeler gauge.
 
NecroWolf

NecroWolf

lost marbles member
Re: very bad miss

okay, i was hoping to hold out for hardlines for my vacum lines but such is my life
 
Don W.

Don W.

Stab it and steer it
Re: very bad miss

If the miss is at idle let it miss for a few minutes then pull the plugs and see which one is different to find the culprit. Also you can sometimes feel for a cold exaust manifold right where it bolts to the head but I've never done that on a Sy.
 
NecroWolf

NecroWolf

lost marbles member
Re: very bad miss

the feeling for exhuast heat sounds like the pulling the plug wire trick off, gotta get a friend for that.
 
NecroWolf

NecroWolf

lost marbles member
Re: very bad miss

well tracked it down. somehow i flattened a plug. no clue. regapped it and it's back to running good.
 
S

SnakeEater

Sleep Dog Racing
Re: very bad miss

Dirty, im having this same problem, only, when i pulled my front drivers side plug, its coated with unburned gas..Same steps? start with vacuum lines or does it sound like my problem could be a little worse like a valve or something....jus replace all the plugs gapped at .35...started it and its still missing
 
NecroWolf

NecroWolf

lost marbles member
Re: very bad miss

if it's coated with unburnt gas i'd look for a spark problem, check the resistance on your wire and make sure it's plugged in good and tight. cause if it's convered in unburnt gas chances are it's not firing or your injector is stuck and hosing it down really good
 
S

SnakeEater

Sleep Dog Racing
Re: very bad miss

FOUND IT....snapped and bent a push rod...straight killed it....not a big deal, but i was starting to get a little nervous that it was something major....jus shitty cause ive only had this HIGH MAINTAINCE bitch for about 3 weeks and already snapped a push rod......
 
You must log in or register to reply here.
Top