85 F150- Help Needed
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85 F150- Help Needed
A couple months back a friend of mine and I bought for $500 a 85 F-150 with a 300 six that needed a rebuild (straight body), had it rebuilt and dropped back in, and now we are stuck (neither of us know alot of mechanical stuff, nor do we pretend to). The guy we bought the truck from said that alot of the electronics and vacuums that were hanging free were from a 302 that was once in it and we did not need to worry about them. We got tricked. NONE of the vacuums on the carb were hooked up. By this point we sunk alot more $$$ than we planned on into the truck and now have a carb with vacuums hanging off it leading to bolts and screws. We are trying to rerun the vacuums ourselves but can't find a diagram of the carb thats on there. Its a single barrell with a manual choke(i will put some pics up here asap) any advise/tips/diagrams would be a huge help-
Thanks
Thanks
Postmaster
Joined: May 2004
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It's my understanding the autozone site has good vacuum diagrams.
I can tell you where a line goes if you tell me where it's coming off from.
This truck sounds iffy, I would do a compression check on all cylinders to know what you have before you do alot of work/money.
You could also put a vacuum gauge on it, watch the needle as someone cranks it.
If the needle does any major drop=major prob.
I can tell you where a line goes if you tell me where it's coming off from.
This truck sounds iffy, I would do a compression check on all cylinders to know what you have before you do alot of work/money.
You could also put a vacuum gauge on it, watch the needle as someone cranks it.
If the needle does any major drop=major prob.
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The truck "runs." The engine itself is in great shape. After we got the engine rebuilt by a great local guy, we had it put in by a friend of a friend, who warned us about the vacuums. We cranked the truck up and drove it about ten miles down the highway to my house. It ran RICH (manual choke vacuum not hooked up). After that it just wouldn't do much for us with that carb running so rich and no vacuums supplying it anything. Anytime we cranked it, when we put it in gear, it would go too low to run and stall. I found an autozone diagram of the closest carb I could find and tried to go by it, but its a bit different than our carb and its hard to figure out what is what.
Tuned
Joined: Jan 2006
Posts: 290
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Let me see if I got this story right. You have a 85 pu w/ a rebuilt 76 I6 300 motor. Was the 76 I6 running in the pu before the rebuild? The reason I ask is I have a 85 van and it came stock with a computor that changed the timing. I removed the computor and now the timing is changed by vacumn. See if you have a vacumn port on your dizzy. If not your dizzy needs a computor to change timing.
Your vacumn does not come from the choke. It comes from the intake manifold. I don't believe your choke needs vacumn. Your carb might need it. I can't get to my van right now cause it time to feed my face.
Your vacumn does not come from the choke. It comes from the intake manifold. I don't believe your choke needs vacumn. Your carb might need it. I can't get to my van right now cause it time to feed my face.
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No, the engine wasn't running, the guy who rebuilt it said it had no compression on multiple cylinders. There isn't a vacuum on the distributor, but there is a computer sensor of some sort. The carb isn't the original, and there is a valve on the choke with a cut vac tube coming off it. I really need to get some pictures up here.
Tuned
Joined: Jan 2006
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Well I got good news and bad news. The good news is you have a motor that will last you 20 years of good service. The bad new is all the sensors that run the computer have to work in order for the timing to work the way it was designed. The stock carb was what is known as a feed back carb and it had wires running to it. I got the feeling you have a different older carb, which might be what you want anyway. To cut to the chase, if you think you still have all the sensors and computer, oh have you found the computor yet?....man, it's really hard to tell what you have.....any way, you might end up nixing all the sensors and computor and going old school, before computors. It's a lot e-zer and cheaper than you might think. You need a dizzy with vacumn advance and the rest of the sparky stuff from a rig pre computors. Do some searches for info on this site and others....got to go... to feed that hole again.
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Elder User
Joined: Sep 2003
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Here is a quick way to determine if you have a TFI computer controlled system or a Duraspark II system.
Look at the coil - if it is a square coil it's a TFI computer controlled - if it's a round cylinder coil it's a DSII.
If it's a DSII, you should have a vacuum advance actuator on the side of the distributor.
Report back what you find - we'll go from there.
Oscar.
Look at the coil - if it is a square coil it's a TFI computer controlled - if it's a round cylinder coil it's a DSII.
If it's a DSII, you should have a vacuum advance actuator on the side of the distributor.
Report back what you find - we'll go from there.
Oscar.
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