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I need a little advice

  #1  
Old 04-30-2010, 02:52 AM
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Default I need a little advice

I got a 71 k 5 and i changed the carb to a bigger one, had a small fire put it out with water, big oops but i pulled plugs out and cranked till there were no more drops coming out. what caused the fire was a burned out regulator shorting the ground and it sparked by the carb. No damage to much tho just a couple wires and a hose that i cut the bad part off. I replaced the alt and v regulator put the carb back cleaned the plugs and it started up rough then smoothed out. I thought i was good till i put it in gear. It dies out when i give it gas. I didnt mess with the distributer at all and plug wires are in correct spot. If water got in my dist 2 weeks ago could it cause this? what else might i need to be looking at because i am stumped right now
 
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Old 04-30-2010, 02:58 AM
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Very possible there might be water in the cap and rotor. WD40 is great for removing water from parts like that. What wires got burned and how bad? Also pics would help with the problem solving.
 
  #3  
Old 04-30-2010, 06:29 AM
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You may also have water in the carb. Another possibility is that the carb fuel bowl(s) just are not full yet and it doesn't have enough fuel in them to support off idle engine speeds.

*Moving to Fullsize K5 Tech*
 
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Old 04-30-2010, 03:50 PM
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Wires that got burned were the solenoid wire, and the wire going to the voltage regulator and a wire on the distributer. I replaced all three and theres no other visible damage, a pic will only look like a motor with no damage. I can take a couple anyways later on i will post them. I took the distributer apart and cleaned it up, no water in it and only the contacts looked a little worn so i cleaned those up as well. Put it back together and rechecked the plug wires three times and. started it up. Same deal. I cleaned the plugs, same thing. I noticed a litle water come out the exaust at first when i floored it in park. Not much a few drops then back to normal gas smelling exaust. The guy at auto zone said it may need to be retimed because the cfm on the new carb is 750 and the old one was 600. Its and electronic distributer now so how do i time that? i moved the wires one plug over each way and it wouldnt start till i put them back to where they were. When it is running I can hear a slight ploop ploop ploop sound from the motor. Its very light and barely noticable but i dont think its normal. If i pull the valve covers off to look at the rods is there antything else i can tell by that?

fire was like 20 seconds long so i didnt have much damage at all but the water was my concern. I didnt turn the motor with plugs in till i got it out so the little residue that might have been in there shouldnt have cause hydro lock.

Ok so i got frustrated after i looked at the distributer I pulled the valve covers off. On te passenger side cylinder 4, the rocker was so loose that i could almost pull the rod out without unscrewing it. I took it out and noticed a slight bend in it, went and bout a whole new set of rods even tho some were not bent at all but for a buck a piece why not replace all them. I havent put them in yet and am wondering if its that off could that be my misfiring troubles, and what would have caused it to bend like that, it wasnt too bad just noticable when i rolled it on a table. but the loose part concerned me. A few others were loose as well. but not as bad. It did sit for six years could starting it up after so long done that with the bad carb that was on there?
 

Last edited by swartlkk; 04-30-2010 at 05:35 PM. Reason: **Combining Consective Posts** - Please use the EDIT feature to add information to your post if another member has yet to reply.
  #5  
Old 04-30-2010, 05:43 PM
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Well, the answer to what could have caused the rod to bend could be one in the same as what caused the fire (besides your original assumption). A backfire through the intake could bend a push rod and/or valve as well as cause a fire on the outside of the engine. A back fire will push whatever fuel is already in the intake and what is near the venturi on the carb out through the top of the carb and if you aren't lucky, it can catch things on fire. Especially if there is fuel out there already.

As far as timing the engine goes, disconnect the vacuum advance and time it just like you always have.
 
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Old 04-30-2010, 10:58 PM
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Originally Posted by sixyearsdown View Post
Wires that got burned were the solenoid wire, and the wire going to the voltage regulator and a wire on the distributer. I replaced all three and theres no other visible damage, a pic will only look like a motor with no damage. I can take a couple anyways later on i will post them. I took the distributer apart and cleaned it up, no water in it and only the contacts looked a little worn so i cleaned those up as well. Put it back together and rechecked the plug wires three times and. started it up. Same deal. I cleaned the plugs, same thing. I noticed a litle water come out the exaust at first when i floored it in park. Not much a few drops then back to normal gas smelling exaust. The guy at auto zone said it may need to be retimed because the cfm on the new carb is 750 and the old one was 600. Its and electronic distributer now so how do i time that? i moved the wires one plug over each way and it wouldnt start till i put them back to where they were. When it is running I can hear a slight ploop ploop ploop sound from the motor. Its very light and barely noticable but i dont think its normal. If i pull the valve covers off to look at the rods is there antything else i can tell by that?

fire was like 20 seconds long so i didnt have much damage at all but the water was my concern. I didnt turn the motor with plugs in till i got it out so the little residue that might have been in there shouldnt have cause hydro lock.

Ok so i got frustrated after i looked at the distributer I pulled the valve covers off. On te passenger side cylinder 4, the rocker was so loose that i could almost pull the rod out without unscrewing it. I took it out and noticed a slight bend in it, went and bout a whole new set of rods even tho some were not bent at all but for a buck a piece why not replace all them. I havent put them in yet and am wondering if its that off could that be my misfiring troubles, and what would have caused it to bend like that, it wasnt too bad just noticable when i rolled it on a table. but the loose part concerned me. A few others were loose as well. but not as bad. It did sit for six years could starting it up after so long done that with the bad carb that was on there?
Why was it sitting for 6 years. Ive gotten many cars that "ran good till I parked it" six years ago. Then I get it home and turn it over to find it knocking or leaking water into the head (overheated). Also I have seen valves stuck in the guide after sitting for several years. That can bend push rods. Also I have seen cams go flat or lifter collapse after an sitting for long periods. Back firing can bend push rods also.
 
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Old 05-02-2010, 10:11 AM
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just out of curiosity how big of a Carb did you put on and what size engine? Cause i just bough a 86 with a 305 and someone put a 750 4 barrel on it and when i put it in gear it trys to die as if its getting to much gas. When i turn it off, it reeks of gas.
 
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Old 05-04-2010, 12:20 AM
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Well its a chevy 350 and i put an eddlebrock 1407 on it which is a 750 cfm. I did take the valve covers off to find a very looses rocker on it. I replaced the rods one was bent, and now its running great. Took it on the highway and everything seems normal again, all power restored and better than it was. wooo hoooo. K5 country boy, that was my problem so bad, i tried everything and it turned out just what i sadi now. loose rocker and bent rod on cylinder 3. fixed it and my problems cured.

It sat for so long because my girlfriends an idiot. said it didnt pass emissions back then so she just sat it down, didnt ever try to start it after that. What a waste, so i convinced her to give me the truck and now shes kicking herself in the *** for it.
 

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  #9  
Old 05-06-2010, 07:27 PM
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Originally Posted by sixyearsdown View Post
Well its a chevy 350 and i put an eddlebrock 1407 on it which is a 750 cfm. I did take the valve covers off to find a very looses rocker on it. I replaced the rods one was bent, and now its running great. Took it on the highway and everything seems normal again, all power restored and better than it was. wooo hoooo. K5 country boy, that was my problem so bad, i tried everything and it turned out just what i sadi now. loose rocker and bent rod on cylinder 3. fixed it and my problems cured.

It sat for so long because my girlfriends an idiot. said it didnt pass emissions back then so she just sat it down, didnt ever try to start it after that. What a waste, so i convinced her to give me the truck and now shes kicking herself in the *** for it.



well at least you got it up and running like it should. i think that 750 is just to big for a 305. now a 350 it should be good as long as its tuned right. I just don't understand why in the world would anyone put a 750 on a 305 it just crazy. But one thing i will say is it gets up and goes. It has some power to turn those 35's
 
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Old 05-06-2010, 07:39 PM
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A 750cfm carb being too large for a small block depends on a lot of things. If it is mechanical secondaries, then yeah, I'd agree. But vacuum secondaries... Not so much. If tuned properly, a large vacuum secondary carb will work good.

Just think about this for a minute... Stock Q-jets run 750cfm to 800cfm depending on what they came on originally. For the small block trucks, it was 800cfm on everything after '76 on up.

The engine will only pull in as much air as it can. You just need to tune it so that it is feeding the proper amount of fuel. I will say that it is much more difficult to tune a carb that is too large for a motor. A mild 350 will only really require 600-650cfm.
 
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