84 c10 power issue

[jjewett444]

i have searched all over the internet and can not find a specific clue as to why all of a sudden my c10 lost all of its power. i have been fixing it up and am about to put it on the road tomorrow so gotta get it fixed. have recently installed painless tcc lockup kit and it had power after it was installed. recently found a set of ram horns to put on, things didn't fit well so switched back and all of a sudden the truck feels real rough when put into drive or reverse and when i drive across the yard it doesn't have much power like the rpm's are governed or like it would feel when not warmed up, also when in park or neutral it idles fine and revvs up fine. almost forgot to mention I tried driving it in the yard with the lockup disabled too(unplugged wire at vacuum switch), made no difference. if anyone can shed some light on this it would help me greatly for tomorrow. thanks

-Jim

 

[1low4x4]

Vacuum related prolly. Idles higher rpm, vacuum fine. Drop into drive and rpm goes down, and if you have a vac leak then it runs like crap

 

[jjewett444]

ok gonna do a fine search for a vacuum leak today. could trans fluid levels be an issue? when i installed the tcc kit i refilled between 4 and 5 qts. also forgot to say when i got the truck the previous owner didnt have the tv cable hooked up due to lack of knowledge probable because the bracket on the manifold wasnt right at all(way too far back) so i bought the tci bracket and it fits now. but it seemed to work right until the manifold swap

 

[throttle out]

Was the truck being driven with the TV cable disconnected? If it was it did not do your trans any favors.
Did you get to test drive the truck after installing your TCC kit?

 

[jjewett444]

just got the truck on the road today, doesn't seem to have any vacuum leaks. I have no idea if it was driven with the TV cable disconnected. I drove it around the block. Passenger side smoking, probably valve seals, also noticed it didn't want to shift out of first(only went up to 25-30) but i also got on it a little and it should have shifted. After i drove it i decided to pull it up in front of the house about an hour later, for the heck of it i plugged the vacuum switch back in, started it, then kinda tried to see what it would do in all gears for about 10 ft or so. all of a sudden 1st (manual) and all the way up to OD had decent throttle response but still idles rough when not in neutral or park.. Also do not know if TV cable is out of adjustment, seems every time i adjust it it slips out like the plastic gears are stripped... gonna to some test and tune tonight i think

 

[MikeB]

Man, don't drive it if you are having issues with the TV cable. Unlike earlier transmissions which used "kick-down" cables, pressure in the 700R4 is governed by cable position, so you will cause damage with it improperly adjusted.

There's hundreds of articles on the Internet on how to properly adjust the cable. If it's somehow slipping, then fix that problem before you drive the truck.

You may have some engine problems too, but focus on the TV cable first!

 

[jjewett444]

just got the transmission rebuilt, 3rd and 4th were gone. also put in new gas tank and discovered my metal fuel line was kinked so i cut it and put a piece of trans cooler hose on (seems to work so far). also while i was at it i put in the proform hei tune up kit and had to switch back to the stock mechanical weights and springs to hake it run ok. it has the adjustable vac adcamve and i've tried all settings and the truck has really low power. It seems to idle fine, vac advance seems to run a tad better on manifold vacuum as opposed to ported. i hooked up vac gauge to a manifold source and iyt rapidly moved around 15hg (stays there just needle shakes hard) and after wot deceleration the needle will only sweep to about 20-25 hg. im almost positive there are no vacuum leaks but possible throttle shaft on the quadrajet. im stuck here people!!! please help me out

 

[74 Shortbed]

Man, don't drive it if you are having issues with the TV cable. Unlike earlier transmissions which used "kick-down" cables, pressure in the 700R4 is governed by cable position, so you will cause damage with it improperly adjusted.

There's hundreds of articles on the Internet on how to properly adjust the cable. If it's somehow slipping, then fix that problem before you drive the truck.

You may have some engine problems too, but focus on the TV cable first!

YES, by all means make sure that cable is adjust properly..

 

[jjewett444]

checked timing it was 2 degrees btdc changed it to 4 btdc. tried adjusting the vacuum advance and has good idle and alright part throttle but mid and wot the power just isnt there. i noticed that it appears to be leaking fuel from carburetor like around both sides of prrmary throttle shaft

 

[74 Shortbed]

checked timing it was 2 degrees btdc changed it to 4 btdc.

What's your total advance, that's what matters..

 

[jjewett444]

i'm not sure because i do not have timing tape to measure more degrees than my stock timing tab and do not have a tach. i have stock hei with proform hei tune up kit but my stock mechanical advance components and the proform adjustable vacuum advance. all emission crap is off truck so i set static timing with vac advance isolated to 4 btdc. i assume total timing should be at factory settings +2 degrees of static i added.

 

[jjewett444]

also truck came with a conventional hei not esc one. although the truck did have power before i installed tune up kit. im thinking about vacuum advance issue. i checked timing with vac advance hooked up and still at 4 degrees btdc at idle so its like its not functioning, and advance is hooked to manifold vacuum not ported. or other possibility is vacuum leak at carb. truck stalled and wouldnt start the other day until i tightened the air horn screws very tight

 

[74 Shortbed]

Well, you won't know what the total is until you check it, you don't need a tape just borrow or rent a dial back timing light, you don't need a tach to see how much total you have just rev it up till you have full advance, the tach tells you what rpm you reach full advance, and that is checked with vacuum advance disconnected.. If you have no change when connected or disconnected you need a new vacuum advance unit..