Truck troubles

[cpasseno03]

Can anyone help me out with this? My truck, a little dodge carbureted 4 cylinder will start missing horribly after a little bit of driving in the winter here. I cannot figure out what it is. I put in new plugs, wires, cap and rotor. It helped for a little while but then the problem came back. If you hammer on it it will pick up the rest and run normal, untill you let off. It also idles rough, but good enough to stay going. If you keep messing with it and revving it it will soon start backfiring thru the exhaust and shootin flames. But on a warm day or in the summer it fires right up and runs like a clock. it is getting up to operating temp, usually before it starts coughing. Any ideas??? I am stumped.<br />Thanks<br />Craig<br />passrdcc@nmo.net

 

[FLATHEAD]

Re: Truck troubles

Just a guess here but it sounds like maybe a vacume leak. Could try looking at the vacume hoses, also a bad intake gasket might cause some of your symptoms.<br /><br />----------------<br />Flathead

 

[B_Eager]

Re: Truck troubles

Could use a little more data to give you some help.<br />Year<br />Make<br />Motor Size<br />When you pulled the old plugs, what did they look like??<br />Hook up a vacume gage before you even start the truck and let it go through war up, and watch closely what it does.<br />Is the truck old enough to have manual timing control. Not computer control.

 

[cpasseno03]

Re: Truck troubles

1988 dodge ram 50 (little import) 2.6L 4cyl. I think it has a hall effect distributer... the old plugs looked good, nice crisp brown. but like I say, this only happens when its cold, and will sometimes go away and clear up. I think one or two of the plugs were a little black and sludgy but not too bad. Thanks for the help! <br />PS flathead, my dad reccomended I start it and squirt a little starting fluid on the vacuum lines and connections, and listen for a rev. pretty good idea I thought...<br />Thanks again<br />Craig

 

[magster65]

Re: Truck troubles

A couple guesses here... This is going to sound funny but fire it up and when it starts to run crappy put a heater by the carb so the warm air goes into it. If that helps or fixes it, your carb is icing up / fix heat shield or piping and 'flapper' valve on air filter housing. Check your firing order... I know, but do it anyways. Backfiring in the exhaust is unburnt fuel usually, I'd look at your coil possibly and wipe out the inside of your cap. Check your plug gaps. Flames out the carb indicate a lean condition or timing that's way out... put a timing light on it and bring the revs' up slow. You'll see something not right. Tell us what it is when you're done

 

[FLATHEAD]

Re: Truck troubles

Yes Craig The starting fluid method does work. Why your at it spray some around the intake and see what happens. Also sometimes a leak at the exhaust manifold will cause backfiring when you ease up on the pedal. Cold air + hot exhaust = KA-BOOMB.

 

[cpasseno03]

Re: Truck troubles

I checked the vacuum system all out. It seems to be fine, and pretty good suction at that. You mention exhaust manifold leaks...I have a real bad leak on the EGR pipe... How about that? I have some aluminum roofing flashing and hose clamps on it, but it still is pretty bad. You think this could cause a problem???<br />Thanks!<br />Craig

 

[NOSLEEP]

Re: Truck troubles

 

[NOSLEEP]

Re: Truck troubles

If your EGR valve or manifold piping is leaking<br />that most certainly will cause some of the <br />symptoms you are describing

 

[SS MAYFLOAT]

Re: Truck troubles

This might sound odd, but I have had problems with my van on cold mornings that is just around the freezing point. Once it warms up it is fine. Found out that is was salt residue from the highway got on the dist.cap. When the moisture got on the cap it cause serious missfiring while it was cold. Salt draws moisture. I see that your from Michigan, so I know that you must drive in road salt. Just a thought......SS

 

[cpasseno03]

Re: Truck troubles

I will have to do some rigging on the EGR valve and see if it helps. SS you are right about the road salt on the distributer, I have been popping it off from time to time and giving it a shot of WD which sometimes helps, but it is only masking the real problem. Thanks for all the help!<br />Craig

 

[Skinnywater]

Re: Truck troubles

Ether/starting fluid isn't very safe for this type of diagnosing. Use spray carb kleen, you'll lose less hair.<br /><br />DO a compression test first.<br /><br />Fix the EGR and make sure the EGR valve isn't sticking open.<br /><br />Check the throttle shaft in the carb for slop and play. The shaft as is passes thru the carb body or base.<br /><br />The choke has to be checked, working and adjusted properly.<br /><br />The choke pull-off vacuum pot has to be checked and working.<br /><br />The spray jet in the carb has to be spraying. And the secondary main jet has to open when reving past the point of secondary transition. <br />Fifteen years use before a carburetor rebuild isn't unreasonable.<br /><br />Your past problems as well as this one, as well as age, the catalytic converter has been taking a pounding.

 

[norman158]

Re: Truck troubles

try a bottle of HEET deicer in the fuel tank

 

[SpinnerBait_Nut]

Re: Truck troubles

Yea skinny hit it on the head. <br /><br />Don't use starting fluid, for you might just have a 4cyl. blow torch on your hands. <br /><br />Check the intake while it is at idle and see if it looks white, if it is, then it is getting moisture from somewhere and trying to ice up most likely right under the carb.

 

[one more cast]

Re: Truck troubles

My Dad had a Mazda with the same sort of trouble.Next time it skips, stop and pop off the dist. cap and see if the inside is wet with condisation.

 

[NOSLEEP]

Re: Truck troubles

If your truck backfires out exaust or intake it<br />indicates a spark timming problem . If it is<br />intermitant it could be that your distributer cap<br />is cracked. Very hard to see with your eyes but<br />you may be able to make out a hair like crack<br />in the cap.

 

[dkondelik]

Re: Truck troubles

I had an ol' '81 D-50.<br />Fine "Rittle" Truck. Wife finally got rid of it because the bed was so rusted-out that she was afraid one of the kids would fall through it when we had it at the beach.<br /><br />I personally never experienced the BIG problem that these Mitsubitshi's had, BUT,... I've know of several that all suffered from a "CARB" problem.<br /><br />Something squirly with these carbs (the ones with the class window on the side of the carb). They seem to need rebuilt or replaced after a while. After they bugger-up, hard to get rebuild parts for the '80 model. Maybe the 88 is more availble. Or is it Injected not carbed? This would be the SECOND place I would look for the problem. <br /><br />The first thing to try regardless of Carbed or Injected? I would go with Norman158. Who knows what all is in the gas tank of a 15year old machine. Had a similar problem with my '87 ford (when temp was below ~10degF). A bottle of Gas-Treatment cleared it up in about 5 minutes of travel.<br /><br />Good Luck<br />Let us know what you find

 

[cpasseno03]

Re: Truck troubles

haha yeah, Mine is pretty rusty too! My uncle actually gave it to me, the brakes went out and he was tired of fixing it. So I brought it home and started work. It leaked everything liquidy and even some things that werent! In order to replace the brake line and gas leaks I had to go from above, so I put on a pair of gloves and literally peeled most of the bed up It still leaves a trail of rust so I can always find my way home. I will fiddle with the carb and fuel system soon as I get a chance. Thanks everyone!<br />Craig