vwfastg60

So i buckled down did my chains and guieds. I found out that my cam timing has been 180 off and so when putting it together i made sure everything was at TDC. I get it done set the timing to 5degrees advanced like i had done to start out with the motor before and now i have no higher RPM power at all The truck wont rev past 4500 rpm with out 11:1 a/f . I set the timing up stock and it revs to about 4800 maybe 4900 but thats it and above 4 it takes FOREVER to rev. I have tried leaning out the A/F and it just makes it worse. My truck used to pull good at higher RPMs or just half throttle and above now the truck is stronger with a 1/4 throttle then full and in any setting i cant get it to do much more then 45 mph. I messed with it a bunch lastnight and i think i ran it out of gas cause even with the timing at TDC it wont start without holding the gas. It says it has about 1/8th tank but i doubt it.

Any ideas what happened with power by setting the motor all to TDC? Is setting cam timing to 180degrees off some kind of trick to get more high rpm power?

Its been great right before this happened and would run highway speeds + with no issue and now i cant even get to highway speeds.

Any ideas would be great. I have a wide band on it for set up and a light so fire away ideas cause my truck is about worthless at this point.

vwfastg60

I forgot to add mods to the motor. All i have is a webber down draft carb that had just been set up 3 weeks before the chains were done and i never touched that before my first 4 test drives. The motor is an 83 bottom end other then that the motor is stock from what i can tell. Before the chains after my tune it would hold 75 on the highway with no issues and if i ripped on it i could get 90+ out of it. but not much more(gps)....

thanks guys.

vwfastg60

oops.

SCYOTA

If your cam is off 180 then the motor would not run. My guess is that the valve and ignition timing was correct before you worked on it. Barely revving is a sign that your ignition timing may be too retarded. Did you use a timing light to set the timing with the vacuum lines disconnected? Before you mess with the carb, recheck all of your work. I would pull the valve cover and set the crank to TDC. When the crank is at TDC (both rockers on #1 are loose) the cam sprockets key way should be facing straight up in the 12 o'clock position. The mark on the sprocket will be in the 11:55-11:58 position. Once you are positive that the valve timing is correct, pull the distributor. Next, turn the rotor so it is facing straight up (12:00). When you push the distributor back in it should turn counter clockwise to about the 10:30 position. There is a little mark on the distributor housing and it should be in line with the center of the rotor. Leave the distributor centered in the adjustment slot and try to fire it up. Once you get it going, use a timing light to set the timing to 0 degrees with the vacuum lines disconnected. Good luck!

vwfastg60

I did that. I triple checked the cam timing and it was set correctly the distributer was set to the #1 cylinder. I tried pointing it straight up in the air and it wont run at all. Im going to pull the cover again and check the cam timing for the 4th time but im 99.9% sure its right. I lined up the marks on the cam gear with the one on the rocker mounting as both manuals i looked at to double check that was the correct mark. With the rotor pointing at the #1 on the distributor it fires right up. Idles fine. Set the timing to 0 and it runs like poop, Idles great but doing 40 is a chore. Advance it a bit and it runs better but not much. Im setting timing with both vacume lines off with a light. I have tried moving my distributor a few teeth in both directions and either way it runs abou the same but is either just as hard to keep at city speeds or harder.

Im going to grab a gas can and throw gas in it and screw with it some more. I have built a few 22r's re's and rte's and never had a problem like this before. Its really weird.

anotherjeff

The camshaft cannot be "180 off" to the crankshaft rotation!

When #1 piston is at the top of stroke, it can be either 1) EXHAUST, or 2) COMPRESSION/SPARK. As far at the block/crank/rods/pistons are concerned, there is NO difference between 1) and 2). Note that there is no way (markings) to distinguish betwn 1) and 2), until the cam is installed.

With the cam installed, there IS a difference between 1) and 2)! But the only difference is the relative camshaft position. So take your pick.

On the other hand, the distributor, and thus the spark timing, can easily be placed "180 off" to the cam. Then, it will not start...

vwfastg60

ok so the camshaft at this point is in the right way now.

Now that the chain is tight and everything is together the timing marks line up at TDC. Should i set it with the chain off or loose and where it winds up(it turns slightly when the chain is tight) I used that thought when putting it on so once everything was together it would be spot on and thats where that is now.

When the rotor is pointing at the #1 spot on the cap it runs fires right up but runs like poop top end. when i point it straight up it sound like its back firing out the intake.

SCYOTA

With the crank at TDC (dot on the crank pulley directly aligned with the 0 mark on the oil pump) and the chain is tight, the dot on the sprocket should be in the 11:56-11:58 (a little left of the mark on the rocker assembly) position and the sprocket key way at 12:00. If your a tooth off the dot on the sprocket would be past the twelve o'clock position or more near the 11:50 position. Again once that is the way I described, pull the distributor partway out of the head so the distributor gear is disengaged from the cam. Make sure the adjustment slot on the distributor is centered between the clamping bolt to ensure the distributor housing is positioned properly. With the distributor still out and the housing in the correct position, turn the rotor so it is facing straight up (12:00 exactly). The best way is to look at it from over the drivers side fender to make sure its at 12:00. Now that the distributor housing and rotor are in the correct position, insert the distributor. As the distributor is pushed in, the housing should remain in the same place (centered in the adjustment slot) but the rotor will spin counter clockwise into the correct position (about 10:30). The center of the rotor will be aligned with the mark on the distributor housing and everything will be set properly. Hopefully that is a little more clear of an explanation and you can figure it out. Good luck!

vwfastg60

ok everything is as said above. Double, Tripple checked it all and my friend did the same with me. The truck starts but now it will run only with the aid of the skinny pedal. I cant get it to idle at any adjustment of the distributor vacume lines on or off. you always have to be reving it or it will die. Timing marks on the motor/dizzy/cam and so on all are at 0 and the dizzy working it small amounts each way did nothing but make it rev faster and easier or harder and slower as i kept it from shutting off.

any ideas?

vwfastg60

Figured it out.

The carb gasket blew out on one of the backfires. I guess it was the reason for the non idle.

Timed a little hot because it does have 36's and no gears and i do highway drive it. My idle A/F is 15.5:1 i wanted to see what you guys thought about that. Im at elevation so i feel it will be ok but thought id double check your thoughts.

I havent taken it out yet but now that my are staying its gotta be right. I will test drive it tomorrow and see what it does. I didnt mess with WOT settings too much but can fine tune on the way to the shop later this week.