Author Topic: same issue different day  (Read 3125 times)

Offline Cowman85

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same issue different day
« on: May 04, 2009, 09:47:59 am »
Hey guys i have posted a few topics on my truck so far, mainly with the fuel pump. That problem is now fixed but i'm still having an issue with the throttle.

it is usually hard to start when cold, i'm guessing the seals in the bottom of the carb are leaking, i have heard that is a common problem. When this happens the engine kinda sputters/chokes a bit then slowly comes to life, sometimes it doesnt do it at all and it starts better than a brand new vehicle.

at idle the truck is great not a problem in the world, it revs fine and sounds good.
once placed in drive its ok at low rpm, if you play around with the pedal much (flooring it or stepping on it to pass) it will cut out then cut back in, and repeat until i back off, i usually put it into neutral at this point and try revving it, it does rev a little but sounds like its cutting out again.
this happened to me on the highway as well, i eventually had to pull a U and head back at around 80km/h.

most of the basic maintenance has been well kept up since buying this truck less than 2000km ago

i have had issues with a cam lobe(mech fuel pump), i'm thinking either the cam or the carb? have you guys ever heard of something like this??
86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline VileZambonie

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Re: same issue different day
« Reply #1 on: May 04, 2009, 10:13:17 am »
When was the last time you overhauled the carburetor?
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Cowman85

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Re: same issue different day
« Reply #2 on: May 04, 2009, 11:44:58 am »
i havnt yet, thats on the list of things to do, i will end up buying a small 500cfm and just putting the old one in the closet until i have the means to rebuild.
so you think its in the carb? it wouldnt surprise me but it would be nice to pinpoint the problem if possible.

when it chokes out and you try and hit the gas it kinda makes a weird echo type sound from the exhaust,

i have also noticed a sort of whistle sound coming from the pipes when i accelerate as well, at least thats what it kinda sounds like from inside the cab (true dual system but its all stock with glasspacks, they are now cut off about a foot before the rear axle)
86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline Cowman85

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Re: same issue different day
« Reply #3 on: May 04, 2009, 05:19:34 pm »
ya its the carb, she stalled on me today and i had to drive home real slow, had to stick a zip tie down the air tube everytime to get it running to, very fun rush hour!
right now i am looking at some low end 500-600cfm edelbrocks for around $360 CA, i came across a 500cfm for 300 but no one seems to know where it went, maybe there are some used ones out there? i'll do some checking around, let me know if you guys have some ideas.

86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline TexasRed

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Re: same issue different day
« Reply #4 on: May 04, 2009, 10:30:53 pm »
Summit sells a holley clone for $250 USD
http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2DM08600VS&N=700+400304+4294925239+115&autoview=sku

Edelbrock's a little easier to tune though.