Author Topic: Power loss when floored and going uphill  (Read 12826 times)

Offline ackland3

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Power loss when floored and going uphill
« on: October 19, 2014, 11:22:27 pm »
Allright so I cleaned and rebuilt my carb on my 1985 K10 pickup 4x4 with the 305... I was able to rough tune it so it's driveable since it is my only vehicle but when I go up hill or floor it there's almost no response it keeps a constant speed but won't accelerate. I belive there is a vacuum leak at the top end of the carb as someone who rebuilt it before me scraped some of the lip off of it so I took some silicone and plugged it up best I could. I advanced the timing to see if that helped and it did quite a bit but when floored it made a pinging noise so i backed it back off. All of this was done by ear since there is no timing gauge on the cover anymore no clue what happened to it. So the question is why am i having such a loss of power? I can make it idle high and that seems to fix it but then the engine doesn't want to turn off tries to keep running after the key is off... Any ideas?
1985 K10
305

Offline 1987_V10_FARMTRUCK

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Re: Power loss when floored and going uphill
« Reply #1 on: November 11, 2014, 09:15:21 pm »
I have a similar problem, but it has gotten worse... from a post this week, I found out that the Ignition Control Module could be your problem and might be a place to start. It's a cheap fix, under $35 from O'reilly Auto (or similar) Good luck!

Offline ackland3

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Re: Power loss when floored and going uphill
« Reply #2 on: November 11, 2014, 10:07:38 pm »
Where is this located? never had to mess with one before also what the heck is the plug in on the top part of the carb for? it's not tbi
1985 K10
305

Offline Irish_Alley

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Re: Power loss when floored and going uphill
« Reply #3 on: November 11, 2014, 10:47:40 pm »
i wouldnt attribute a power lose with the icm. and if you want to replace the icm you're better off replacing the whole distributor off ebay for $40. does sound like timing is a problem. is your timing advanced hooked up or better yet is it even working?
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Online bd

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Re: Power loss when floored and going uphill
« Reply #4 on: November 11, 2014, 11:32:38 pm »
When did the power loss begin, before or after you took the carburetor apart?  Why did you rebuild the carb? 

Did you replace the fuel filter?  Any chance it was installed backwards?  Check fuel pump draw, pressure and volume.  Post a pic of the "lip" that was partly scraped off the carburetor.  You need to figure out the timing.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline ackland3

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Re: Power loss when floored and going uphill
« Reply #5 on: November 12, 2014, 11:04:52 pm »
this is my daily driver so i can't tear it all apart without having back together the same day will post pics this weekend maybe if i can find time
1985 K10
305

Offline jg1977c20

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Re: Power loss when floored and going uphill
« Reply #6 on: January 14, 2015, 07:42:58 pm »
Does it still have the cat in it ? Likely plugged up the only fix is a new one
1977 c20 cheyenne camper special 8200gvw

Offline FlatBlack77

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Re: Power loss when floored and going uphill
« Reply #7 on: January 14, 2015, 10:18:39 pm »
sounds like the problem has alot to do with timing. probably some other issues in there aswell.

turning the distributor even a little bit can throw the timing way off. doing it by ear is not the way to go whatsoever
"When you are a hammer, everything looks like a nail"
'77 C/10 - 350/350 mild street motor

Offline rich weyand

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Re: Power loss when floored and going uphill
« Reply #8 on: January 14, 2015, 11:55:21 pm »
sounds like the problem has alot to do with timing. probably some other issues in there aswell.

turning the distributor even a little bit can throw the timing way off. doing it by ear is not the way to go whatsoever

x2.  Also, if you didn't get the diffy clamped down right, it will drift retarded, giving you your current symptoms.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift