Dman85 Posted March 23, 2018 Report Share Posted March 23, 2018 I was the recent winner of a 85 2wd extra cab sold to me by a friend. He had it sitting because of running problems he couldn’t fix. So here goes.. it starts and runs ok but a little rough, but when you put it in drive it wants to die and runs really rough.. I have changed cap, plugs, wires... when listening to it I hear a rattle/gargle cling from behind the carb I think from one of the vacuum valve.. any ideas or fixes.. thanks for all your help 1 Quote Link to comment
racerx Posted March 23, 2018 Report Share Posted March 23, 2018 Ask your friend what he thinks the problem is. Hopefully, he is an honest friend and a good one. Issue Maybe vacuum leak, so spray some carb cleaner around intake, carb area, vacuum hoses, and if RPM does go up there's your gremlin. Second, I would check the base timing, 3rd maybe a carb adjust. Good luck. 3 Quote Link to comment
Dman85 Posted March 23, 2018 Author Report Share Posted March 23, 2018 I did spray some carb cleaner around the motor and did. Not get any idle changes. There are two vacuum valves behind the carb, what are they. One of them sounds like it is gargling/knocking. I will check the timing also. 1 Quote Link to comment
datzenmike Posted March 24, 2018 Report Share Posted March 24, 2018 You have an electronic feedback carb with a round 6 wire electrical plug at the rear right side. The wires are too short and are flexed too much sometimes causing them to break inside the insulation and giving intermittent problems with engine shake when idling. I suspect the idle cut, AKA anti dieseling solenoid, (Red wire) may be at fault. Engine off but ignition turned on/off/on/off you should hear a metallic clicking sound. Key on, wiggle the connector and the wires.... if you hear clicking there's a bad connection 1 Quote Link to comment
Dman85 Posted March 25, 2018 Author Report Share Posted March 25, 2018 So I’m confused... with key on not running you shouldn’t here the constant ticking noise. Because that it what I hear. 1 Quote Link to comment
datzenmike Posted March 25, 2018 Report Share Posted March 25, 2018 Is it a buzzing sound or slower clicking? Unplug the harness from the carb to make sure it's the carb. 1 Quote Link to comment
Dman85 Posted March 25, 2018 Author Report Share Posted March 25, 2018 It sounds like the carb ticking... 1 Quote Link to comment
datzenmike Posted March 25, 2018 Report Share Posted March 25, 2018 So did you unplug the harness. 1 Quote Link to comment
Charlie69 Posted March 26, 2018 Report Share Posted March 26, 2018 This is the plug Mike is saying to unplug to see if the ticking noise stops. Quote Link to comment
Dman85 Posted March 26, 2018 Author Report Share Posted March 26, 2018 Ok guys. I appreciate all your help. I will get back on it tomorrow and let you know. Hope it works before it gets towed. 1 Quote Link to comment
Dman85 Posted March 26, 2018 Author Report Share Posted March 26, 2018 Ok so when I unplugged it the ticking went away. So what does that mean? What to do next. 1 Quote Link to comment
Dman85 Posted March 27, 2018 Author Report Share Posted March 27, 2018 He did replace the cap and wires but not rotor.. does the EGR valve on these always sound so loud? I had it running and idling good but once you put it in Reverse or Drive it just falls on it’s Dave and wants to die unless your on the gas. I think the calves need to be adjusted also as it seems to have a lot of valve chatter. I am just confused by this. Unfortunately I have a 1 year old baby so getting a good amount of time at once to do testing is hard. Everyone has been a big help though and really appreciate it. I’m sure it’s something small and am just overseeing the problem. 1 Quote Link to comment
datzenmike Posted March 27, 2018 Report Share Posted March 27, 2018 I don't think it should be clicking at idle. The EGR should not make any sound and it shouldn't be working at all at idle. You sure it's the EGR?? 1 Quote Link to comment
Dman85 Posted March 27, 2018 Author Report Share Posted March 27, 2018 Back side of motor there are two valve one is the BTR and one is the EGR. I can reach underneath it and push up in valve and rattle will go away but engine will start to die. 1 Quote Link to comment
Charlie69 Posted March 27, 2018 Report Share Posted March 27, 2018 Does this truck have oil in the engine. Sounds like it does not have enough oil in the engine. Noisy valves will not stay running. If there is no oil pressure the engine will not stay running. Quote Link to comment
datzenmike Posted March 27, 2018 Report Share Posted March 27, 2018 Back side of motor there are two valve one is the BTR and one is the EGR. I can reach underneath it and push up in valve and rattle will go away but engine will start to die. The ported vacuum line from the carb tells the BPT (back pressure transducer) when ERG can happen. This is under three conditions... A warmed up engine (TVV thermal vacuum valve, only allow signal to pass from carb to BPT when engine ids warm) An engine NOT at idle (no ported vacuum signal) An engine NOT at full throttle (low intake vacuum, no ported signal) EGR happens only at part throttle, part load The BPT samples the back pressure in the exhaust and allows EGR based on engine load. More load.. more EGR but subject to the 3 above conditions. Pull the vacuum hose off the EGR, the EGR is now disabled. If it still makes noise then it's faulty. EGR valves can collect exhaust deposits and need to be removed and wire brushed clean or replaced. A dirty EGR may not close properly and leak exhaust into an idling engine. This will dilute the idle mixture and reduce power and the ability of the engine to idle properly. Quote Link to comment
Dman85 Posted March 27, 2018 Author Report Share Posted March 27, 2018 So this could be part of my problems I’m having..the loud rattling I have been hearing from the back side of motor when idling was coming from one of the EGR valve. Again while idling I could put pressure up under heather with finger and rattle would go away but engine would begin to die. Quote Link to comment
datzenmike Posted March 27, 2018 Report Share Posted March 27, 2018 EGR valve may be broken. Lifting up on the shaft opens the valve and as noted, no engine will run at idle with EGR. Quote Link to comment
racerx Posted March 27, 2018 Report Share Posted March 27, 2018 can you do a compression check? and/or open the valve cover and see if anything is loose or came off or check valve adjust. Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.