TheGeneral Posted December 5, 2021 Share Posted December 5, 2021 Hi there, I am hoping to get some advice on possible engine flush/oil change/additives based on my current situation. I have read through the threads re: oil type so first I will explain what I've got going on. 1985 f150 4.9, California--almost all new smog equipment, new catalytic converter, rebuilt carb, plugs at .046, new distributor, recent cap/rotor, 10W30 (Lots of other new stuff but these are related to my question). She is running rougher and rougher, stinkier and stinkier, with new tick (lifters?) and there is a TON of carbon residue on my brand new tailpipe. 😭😭 I am going to dive into it this week and here is my rough plan. What I need help with is what combination of fluids I need based on having both lifter tick and a new catalytic, as I THINK if I understand correctly, that the 15W40 or other zinc-containing oils are good/better for the flat tappets, but potentially damaging to the catalytics? They were not cheap👀👀 I plan to: Replace PCV valve Replace spark plugs (copper core) and gap at factory .044 Flush engine with _____________???? Change oil to _________________???? 10W40?? So I have zinc but it's not too thick to get up the lifters?? Or a better 10W30 with ZDDP? I am on northern California coast so generally never below freezing but may occasionally drive into the mountains. Find someone who actually knows how to properly time it ___________???? Do I have to take my carb apart or something to clean it, it seems filthy for just being rebuilt this year. Anything else? She runs strong and has a lot of power but I am really having a hard time getting her to run clean and it's pretty frustrating as I have put SO much time and energy into her this year and I am barely getting 12 MPH. I don't want to ruin the engine running so poorly. It must be filthy inside,.but I am super nervous thinking about flushing it and ending up even worse off. Any recommendations or warnings would be incredibly helpful. Thanks everyone for reading this far! Bell Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 5, 2021 Share Posted December 5, 2021 Bell - I'm not a carb guru, much less a YFA guru, but what you are saying about how rough and stinky it is I'm guessing that you are running really rich. And one think that can do that is the accelerator pump in that carb. I'm not sure how best to check that, but before you start flushing the engine and all the other things I think you need to do some more investigation. I'm going to tag Bill/85lebaront2 to see what suggestions he has because he has forgotten more than I'll ever know about carbs. Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 5, 2021 Share Posted December 5, 2021 Ok let's take these one at a time. First, lifter tick, are you sure it is lifter(s) or might it be a leaking exhaust (manifold to head) gasket? It may also be the mixture control solenoid on the carburetor. Rough running, stinky exhaust, lots of carbon in the tailpipe. First thing I always check on a Carter YFA, is for loose screws (not the owner, we all have them for liking 30+ year old trucks) the ones that hold the throttle body to the float bowl. These are the three (occasionally four) that are installed from the bottom holding the aluminum (silver) part to the pot metal (gold) part. The harmonic vibration of the in-line six will cause them to loosen and the weight of the air cleaner doesn't help. This is why Ford used a brace from the driver's side of the head to the air cleaner can. If the screws are loose, with the air cleaner off, you will find you can move the main body of the carburetor, if so, it is rebuild time. The other item is the design of the carburetor internally, there is a diaphragm about 1" across that does double duty. The bottom of it is connected internally to manifold vacuum to pull it down, lowering the metering rod to lean the main mixture. The top side is the accelerator pump and as it is pulled up by the linkage internally, it provides a shot of gas when the throttle is opened with the engine running. Your truck has a feedback system for mixture control, but even with it inoperable it can't get but so rich. The mixture control solenoid affects the air bleeds for the main and idle circuits and is the cylindrical "can" on the valve cover side of the carburetor attached to the top section of the carburetor. It has a two wire plug on the bottom end of it. I hope I haven't overloaded you with information. Good luck with it! Link to comment Share on other sites More sharing options...
TheGeneral Posted December 5, 2021 Author Share Posted December 5, 2021 Bill/85lebaront2: I replaced the mixture control solenoid a while back as well as having the exhaust manifold replaced (it was supposed to be both intake and exhaust but there was a miscommunication 🤐...I did forget to check the carb bolts again (I did several months ago) so I will do that first thing. I'll hold off on the flush but I will go ahead with the oil change... As for the ticking sound I really have no idea, I mean it increases when I give it gas.. probably in over my head LOL. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 6, 2021 Share Posted December 6, 2021 Ok let's take these one at a time. First, lifter tick, are you sure it is lifter(s) or might it be a leaking exhaust (manifold to head) gasket? It may also be the mixture control solenoid on the carburetor. Rough running, stinky exhaust, lots of carbon in the tailpipe. First thing I always check on a Carter YFA, is for loose screws (not the owner, we all have them for liking 30+ year old trucks) the ones that hold the throttle body to the float bowl. These are the three (occasionally four) that are installed from the bottom holding the aluminum (silver) part to the pot metal (gold) part. The harmonic vibration of the in-line six will cause them to loosen and the weight of the air cleaner doesn't help. This is why Ford used a brace from the driver's side of the head to the air cleaner can. If the screws are loose, with the air cleaner off, you will find you can move the main body of the carburetor, if so, it is rebuild time. The other item is the design of the carburetor internally, there is a diaphragm about 1" across that does double duty. The bottom of it is connected internally to manifold vacuum to pull it down, lowering the metering rod to lean the main mixture. The top side is the accelerator pump and as it is pulled up by the linkage internally, it provides a shot of gas when the throttle is opened with the engine running. Your truck has a feedback system for mixture control, but even with it inoperable it can't get but so rich. The mixture control solenoid affects the air bleeds for the main and idle circuits and is the cylindrical "can" on the valve cover side of the carburetor attached to the top section of the carburetor. It has a two wire plug on the bottom end of it. I hope I haven't overloaded you with information. Good luck with it! Thanks, Bill. You know far more about it than I do. Link to comment Share on other sites More sharing options...
mat in tn Posted December 6, 2021 Share Posted December 6, 2021 Thanks, Bill. You know far more about it than I do. i second that carb advice. loose throttle plate screws are a quirk and will definitely make it run rough but normally by causing a vacuum leak. you are seeing a lot of soot so its running rich. double check choke operation. as far as a tick, look closely at exhaust especially the most recent work done to it. if it's a leak in the pipes it will be more of a roar noise but if it's on a certain single cyl it will be a ticking sound. these long manifold combinations have been known to warp a little over time and temp Link to comment Share on other sites More sharing options...
TheGeneral Posted December 6, 2021 Author Share Posted December 6, 2021 i second that carb advice. loose throttle plate screws are a quirk and will definitely make it run rough but normally by causing a vacuum leak. you are seeing a lot of soot so its running rich. double check choke operation. as far as a tick, look closely at exhaust especially the most recent work done to it. if it's a leak in the pipes it will be more of a roar noise but if it's on a certain single cyl it will be a ticking sound. these long manifold combinations have been known to warp a little over time and temp Ok will do. Definitely not a roar. I trust the muffler shop far more than I trust the shop that did the exhaust manifold. I have done a lot of the stuff myself but I get intimidated easily with larger projects that tend to involve broken bolts. My fear is that I will have to redo the entire exhaust manifold to also do the intake and the gasket between them, I still can't believe they went ahead and only did the exhaust instead of insisting I wait until I had an intake....I only learned afterwards about the gasket in between. Well heck though, if I have to do it myself next time I will buck up and do it! I should add that the dieseling has gotten worse--I got it to all but stop after I replaced the valve cover gasket, and I retightened everything a couple times after a few driving intervals, but those bolts are all snug as a bug now, so I do suspect a vacuum leak somewhere else may be part of the culprit. I will report back soon! Link to comment Share on other sites More sharing options...
1986F150Six Posted December 6, 2021 Share Posted December 6, 2021 I should add that the dieseling has gotten worse--I got it to all but stop after I replaced the valve cover gasket, and I retightened everything a couple times after a few driving intervals, but those bolts are all snug as a bug now, so I do suspect a vacuum leak somewhere else may be part of the culprit. I will report back soon! Attached is a link to testing for vacuum leaks on a 1984 4.9L: https://www.ford-trucks.com/forums/1478167-vacuum-leak-detection-effective-and-inexpensive.html Link to comment Share on other sites More sharing options...
TheGeneral Posted December 28, 2021 Author Share Posted December 28, 2021 So an update for anyone who was kind enough to post info: Turns out that the intake to exhaust gasket is leaking as I feared, but also the...throttle pin? at the base of my recently rebuilt Carter carb needs to be rebushed and should have been done when I had the carb rebuilt but was not. So, combined that's about $1k of wasted repairs by highly regarded 'experts' that I should have just bucked up and learned to do myself. Now that I have more time on my hands I suppose I will have to. I also bought new catalytic converters in order to pass smog, so now even if I wanted to convert the carb/emissions setup to a more efficient system (certainly considering) it would mean I wasted all that money as well. I swear I should have figured out a way to register in another state from the get-go. oof. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 28, 2021 Share Posted December 28, 2021 So an update for anyone who was kind enough to post info: Turns out that the intake to exhaust gasket is leaking as I feared, but also the...throttle pin? at the base of my recently rebuilt Carter carb needs to be rebushed and should have been done when I had the carb rebuilt but was not. So, combined that's about $1k of wasted repairs by highly regarded 'experts' that I should have just bucked up and learned to do myself. Now that I have more time on my hands I suppose I will have to. I also bought new catalytic converters in order to pass smog, so now even if I wanted to convert the carb/emissions setup to a more efficient system (certainly considering) it would mean I wasted all that money as well. I swear I should have figured out a way to register in another state from the get-go. oof. The gasket is something that you should be able to do. It just takes normal tools and patience. The carb might not be. Not only do you need to be able to drill the base of the carb through from one side, which requires a drill press, you then need to press the bushings in and then ream them to ensure the hole is aligned side-to-side. Instead you should consider buying a new carb. Link to comment Share on other sites More sharing options...
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