brian hood Posted December 5, 2008 Report Share Posted December 5, 2008 Help! I have an 85 slant six that is all of a sudden running badly. It idles very smooth, but when you are under way, it has no p/u to it. Infact, I can seem to get it to go faster than 35 mph. I took some carb cleaner and looked for an air leak, but I couldn't find one. It does not back fire. Any suggestions or thoughts? Brian Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted December 5, 2008 Report Share Posted December 5, 2008 are you experiencing a possible plugged catalytic converter...what is this engine in..type of carburation etc etc.. Quote Link to comment Share on other sites More sharing options...
Normspeed Posted December 5, 2008 Report Share Posted December 5, 2008 I would look for a restricted exhaust, either the converter or a crimped pipe. Also possibly bad distributor cap, rotor or plug wires. If the converter is plugged you should see a drop in vacuum at the intake when the rpms increase. Quote Link to comment Share on other sites More sharing options...
T120 Posted December 5, 2008 Report Share Posted December 5, 2008 ..Maybe a clogged fuel filter Quote Link to comment Share on other sites More sharing options...
rolliejoe Posted December 5, 2008 Report Share Posted December 5, 2008 I had a '70 dart /6 do that to me. Start and idle great, go to drive it would stumble bad with anything over 1/8 of a pedal. What solved it was running fresh gas through the tank and also adding bottles of Heet (to remove moisture). Quote Link to comment Share on other sites More sharing options...
dezeldoc Posted December 5, 2008 Report Share Posted December 5, 2008 Mid 80's, mucho smog garbage, garbage fuel these days. I would check all the rubber fuel lines and make sure they are not turning to black ooz. I have seen a bunch of this in the past year. If they are ok my bet would be plugged cat or collapsed head pipe. Quote Link to comment Share on other sites More sharing options...
brian hood Posted December 5, 2008 Author Report Share Posted December 5, 2008 Isnt there a way to check them by taking a heat reading or is a good vac guage reading a better method? Quote Link to comment Share on other sites More sharing options...
brian hood Posted December 5, 2008 Author Report Share Posted December 5, 2008 By the way, this engine is in a 85 1/2 ton PU. It is carburated (1 . It has something that looks like a converter, but it has no wires going to it. Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted December 5, 2008 Report Share Posted December 5, 2008 only the later computer controlled models have the O2 sensor attached at/near the cat convertor..older units were had no need for this device.. Quote Link to comment Share on other sites More sharing options...
old woolie Posted December 5, 2008 Report Share Posted December 5, 2008 Could be a plugged converter. I've seen many of these trucks work poorly and have fixed them by tossing the ignition system and converting to the early mopar electronic ignition. Quote Link to comment Share on other sites More sharing options...
oldmopar Posted December 5, 2008 Report Share Posted December 5, 2008 Try this link for some information on a 85 Dodge D150 I think that had the \6. Its a autozone site that has a lot of information for the vehicles they have on line I use it several times for a 79 gmc. http://www.autozone.com/addVehicleId,1150301/initialAction,repairGuide/shopping/vehicleSelected.htm Quote Link to comment Share on other sites More sharing options...
brian hood Posted December 5, 2008 Author Report Share Posted December 5, 2008 Hey, Thanks for the link and all the advice. I will post and let yall know! (yes I am in the South Y'all! ) Quote Link to comment Share on other sites More sharing options...
brian hood Posted December 5, 2008 Author Report Share Posted December 5, 2008 Will it run w/o the converter? My carb is not controlled by the computer. Will that effect the ele ign system? Quote Link to comment Share on other sites More sharing options...
dezeldoc Posted December 5, 2008 Report Share Posted December 5, 2008 yes it will run with out it.Drop it at the 2 bolts on the exhaust manifold and start it up and hit the trottle is about the quickest way to find out if it is plugged or not. if need be you can wire up the pipe out of the way and take it for a spin. Quote Link to comment Share on other sites More sharing options...
Normspeed Posted December 5, 2008 Report Share Posted December 5, 2008 Brian, I had a Dodge Aries, a company car, that did exactly what you describe. The company garage took 2 or 3 tries before they replaced the converter and that cured it. Quote Link to comment Share on other sites More sharing options...
knuckleharley Posted December 6, 2008 Report Share Posted December 6, 2008 Isnt there a way to check them by taking a heat reading or is a good vac guage reading a better method? Your water temp gauge will tell you if your cat is plugged up. If it's not running hot I would suggest getting somebody with a scanner to plug into your wiring harness and check out the trouble codes. Could be a bad gas filter,bad ignition module,bad fuel pump,bad timing,etc. Could even be a fuel line that is weak and collapses on itself when the fuel pump starts to pump harder. Quote Link to comment Share on other sites More sharing options...
knuckleharley Posted December 6, 2008 Report Share Posted December 6, 2008 By the way, this engine is in a 85 1/2 ton PU. It is carburated (1 . It has something that looks like a converter, but it has no wires going to it. You are probably looking at the smog pump. Mounted to the engine and has a pulley,right? The catalytic converter is usually between the exhaust manifold and the muffler. Looks like a small muffler,and usually has a heat shield around it. Quote Link to comment Share on other sites More sharing options...
Frank Elder Posted December 6, 2008 Report Share Posted December 6, 2008 My 84 had the exhaust manifold, pipe, small converter or some thing you could see it by opening the hood, then underneath the actual converter followed by the muffler back by the axle.Never did find out what the first one was but the second"converter" was indeed plumbed into the smog pump. When my smog pump seized up and failed, we installed straight pipe to replace it, truck ran better and my exhaust didn't look like a constrictor with belly full of gerbils! Quote Link to comment Share on other sites More sharing options...
dezeldoc Posted December 6, 2008 Report Share Posted December 6, 2008 Your water temp gauge will tell you if your cat is plugged up. If it's not running hot I would suggest getting somebody with a scanner to plug into your wiring harness and check out the trouble codes. Could be a bad gas filter,bad ignition module,bad fuel pump,bad timing,etc. Could even be a fuel line that is weak and collapses on itself when the fuel pump starts to pump harder. 85's do not have a obd hook up. the temp gauge will not tell if the cat is plugged.Brian, try like I said and drop the headpipe and I will bet you will find the problem. Quote Link to comment Share on other sites More sharing options...
Frank Elder Posted December 6, 2008 Report Share Posted December 6, 2008 Mine had a diagnostic port right on top of the drivers side fender well. Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted December 6, 2008 Report Share Posted December 6, 2008 It is that time of the year. Is your carburetor icing up? Quote Link to comment Share on other sites More sharing options...
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