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Old 12-15-2008, 06:27 PM   #1
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Engine break-in complete, one issue...

It wasnt fire this time. ahaha. Got it started up, ran for 20 minutes. Everything looked really good, stayed nice and cool. I dropped the idle back down, checked the tranny fluid, and then shut the truck off and it diesled quite a bit.... Now, the timing isnt 100% yet, just close for break in.... Once i get the timing dialed in would that take care of the diesling when you shut it down???

diesling= running once you shut it off. I think thats the term..
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Old 12-15-2008, 06:42 PM   #2
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Re: Engine break-in complete, one issue...

was it running on as if you never killed the ignition...
or was it kickin backwards exhailing through the carb, stumbling and acting stupid sounding like a POS?

Both are genericly called run on, and have seperate causes.
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Old 12-15-2008, 09:30 PM   #3
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Re: Engine break-in complete, one issue...

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Originally Posted by Longhorn Man View Post
was it running on as if you never killed the ignition...
or was it kickin backwards exhailing through the carb, stumbling and acting stupid sounding like a POS?

Both are genericly called run on, and have seperate causes.
it was doing the second thing. Run on. I killed the ignition, it started to stop and just did that old beater noise. ahaha.. im assuming its due to the timing being off. I hear it ever so often on some older trucks, but never really knew what it was caused by. What are your thoughts?
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Old 12-15-2008, 09:37 PM   #4
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Re: Engine break-in complete, one issue...

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Originally Posted by Longhorn Man View Post
was it running on as if you never killed the ignition...
or was it kickin backwards exhailing through the carb, stumbling and acting stupid sounding like a POS?

Both are genericly called run on, and have seperate causes.
I read up on it a bit... Few causes lead to what i may have. Wrong spark plug temperature range... And timing out of whack....

Im running ac delco plugs, i will have to look and see what plug they are... I dont really know what to run on my engine... Big cam, about 9.8-10 or so compression or so....

Thanks for the response LHM. It sounded so good running today.. Stayed nice and cool and just went very well. Now i can get my darn cab on and start gettin to work. My garage is about 39 degrees though so it gets a little rough out there...
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Old 12-15-2008, 09:38 PM   #5
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Re: Engine break-in complete, one issue...

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Originally Posted by Longhorn Man View Post
was it running on as if you never killed the ignition...
or was it kickin backwards exhailing through the carb, stumbling and acting stupid sounding like a POS?

Both are genericly called run on, and have seperate causes.
ohhhh, one more. Run on solenoid... Does my vehicle have one of those? Its an 81 quadrajet... I dont think it has one, but i honestly dont know what they look like.
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Old 12-15-2008, 09:44 PM   #6
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Re: Engine break-in complete, one issue...

What, no fire show? You're making progress then. I bet it sounds good.
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Old 12-15-2008, 10:19 PM   #7
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Re: Engine break-in complete, one issue...

timing, high idle, spark plug heat range (not likely) hot spots in the engine due to carbon (again, not likely), too low a grade of fuel...
set your final tune, (idle and timing) and see what it does.
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Old 12-15-2008, 11:53 PM   #8
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Re: Engine break-in complete, one issue...

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timing, high idle, spark plug heat range (not likely) hot spots in the engine due to carbon (again, not likely), too low a grade of fuel...
set your final tune, (idle and timing) and see what it does.
I had some old gas in the tank, and i added 5 gallons of some 92 in there... What is your recommendation on spark plugs???

Idle is at about 750??? Timing i havent set that yet. Soon....
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Old 12-16-2008, 12:04 AM   #9
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Re: Engine break-in complete, one issue...

I have had good luck with AC Delcos....R45TS to be exact. I am now running the Accel shorties though and they're not too bad....especially easy to prevent plug wire burn with headers.

Timing is the usual cause of run on....back it off a bit and try again.
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Old 12-16-2008, 02:15 AM   #10
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Re: Engine break-in complete, one issue...

Usually run on means you have the idle set too high at the carb to make the engine run.

Get your timing set right, then idle mixture screws set to highest vacuum, and I would bet that idle gets higher so you are able to get that idle screw turned down a bit so it will stop the run on.
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Old 12-16-2008, 01:34 PM   #11
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Re: Engine break-in complete, one issue...

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Usually run on means you have the idle set too high at the carb to make the engine run.

Get your timing set right, then idle mixture screws set to highest vacuum, and I would bet that idle gets higher so you are able to get that idle screw turned down a bit so it will stop the run on.
Ohh.. ok. I think i will have a buddy help me with that... I dont really know where the idle mixture screws are. Actually, i do, but i dont want to screw it up. ahaha...
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Old 12-16-2008, 02:04 PM   #12
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Re: Engine break-in complete, one issue...

When you get it running right, we need another vid
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Old 12-16-2008, 02:16 PM   #13
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Re: Engine break-in complete, one issue...

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When you get it running right, we need another vid
It runs GREAT!!!!... It just doesnt shut off so well. ahah Im sure the timing is off. I just get nervous adjusting timing because everyone says its so bad to let a new motor idle. I have spent about 25 or 30 mins breaking it in, so i dont know if its ok to idle it for awhile to do the timing....
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Old 12-16-2008, 02:27 PM   #14
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Re: Engine break-in complete, one issue...

Before you mess with the idle mix screws...back off the timing a bit. 9 out of 10 times that cures the problem.
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Old 12-16-2008, 02:31 PM   #15
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Re: Engine break-in complete, one issue...

Had that run-on issue with my K10, was still there after squaring away my timing, turned out to be my carb (600CFM Holley) was wide open and dumping too much gas. Looked up the Holley's model # online, located a schematic and adjusted...truck runs like a top now.
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Old 12-16-2008, 02:38 PM   #16
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Re: Engine break-in complete, one issue...

Ive had good luck w/ the AD Delco R45s as well. just make sure which era 350 block you have...The suffix T plugs will not fit unless you have a later model engine or heads with taper seats. The R45S plugs I mentioned are for the gasket type seat..... R45S for gasket type & R45TS for tapered seat.

R43 = cooler
R44 = warmer
R45 = hotter

I doubt that the plugs are causing any of your issues, but if you're running a high compression then you'll need some 93 octane fuel-
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Old 12-16-2008, 02:51 PM   #17
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Re: Engine break-in complete, one issue...

err, *cough* 454 *cough* LOL.....

You said 350 block. Will that work for a 454 block????

Im definetly going to do timing first... Once i get the cab on, im going to run the truck again and check temps.. Make sure nothing else catches on fire....
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Old 12-16-2008, 02:59 PM   #18
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Re: Engine break-in complete, one issue...

after it ran you could look down the bores of the carb to see ifm theres a little puddle of fuel on the botom of the manifold that might point to a slightly flooding carb or maybe one corner of it being rich .
did you checked the colour of the plugs after it has run ?
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Old 12-16-2008, 03:01 PM   #19
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Re: Engine break-in complete, one issue...

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after it ran you could look down the bores of the carb to see ifm theres a little puddle of fuel on the botom of the manifold that might point to a slightly flooding carb or maybe one corner of it being rich .
did you checked the colour of the plugs after it has run ?
No, i will check that here soon. I stuck my hand over the carb to cut the air off and it shut right down.
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Old 12-16-2008, 04:51 PM   #20
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Re: Engine break-in complete, one issue...

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err, *cough* 454 *cough* LOL.....

You said 350 block. Will that work for a 454 block????

Im definetly going to do timing first... Once i get the cab on, im going to run the truck again and check temps.. Make sure nothing else catches on fire....
OHH BIG TIME!!!! Look at me assssuming that everyone is running a small block!!

I do not know if these are the correct plugs for a 454, I would like to know when you find out-
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Old 12-16-2008, 04:59 PM   #21
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Re: Engine break-in complete, one issue...

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OHH BIG TIME!!!! Look at me assssuming that everyone is running a small block!!

I do not know if these are the correct plugs for a 454, I would like to know when you find out-
HAHAH, no worries.
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Old 12-16-2008, 05:19 PM   #22
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Re: Engine break-in complete, one issue...

You probably hit the nail on the head with the comment on the "Big Cam". If your cam is large enough to require adjusting the carb idle speed up to keep the engine running at (IDLE) conditions, then you are probably in the transition area from the idle area to the operationg area of the carb. The carbs area designed to have a certain amount of air passing by that pulls fuel out of predesigned idle orifices for a proper idle mixture. The cam (with a lopey operation) will make you want to adjust the carb idle screw further in to make the engine continue to idle without dying. That will be a major part of your change over to this cam profile.

I recommend a timing adjustment to get the proper spark profile and then move on to the idle mix screws (adjusting with a vacuum gauge would be best). After that set the idle speed on your engine to make it work. If you have an automatic tranny, you may have to consider a "Stall Convertor" to make it streetable. I had to take my truck to a 2400 stall to get around the cam profile.

Do you have an idea of where you want to set the timing at? I took my stroker motor to a 35 degree (TOTAL ADVANCE) and that allows the engine to operate more efficiently with the cam that I am running. That also made the idle adjustment easier and I now have my truck idling without a lot of the gassy smell of not being in the proper idle circuit area of the carb. It will take time, but work with it.
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Old 12-16-2008, 05:48 PM   #23
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Re: Engine break-in complete, one issue...

You hit mine on the head also. I do have a 2400 stall converter on it. The carb is a stock quadrajet if that matters... Im going to get the timing set and then start going from there. Im not going to touch the adjustment screws until i have someone who knows their way around these carbs is with me...

Right now it idles perfect at around 800 rpms or so.
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Old 12-16-2008, 05:55 PM   #24
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Re: Engine break-in complete, one issue...

Too much timing, idol too high and possibly a bit rich. fix them in that order and you should be good to go. Make sure you dont idol it too much without breaking the cam in. And even then, you should take it for a drive asap.
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Old 12-16-2008, 07:08 PM   #25
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Re: Engine break-in complete, one issue...

dunno if this is treu but i heared a story once about tuning the ignition untill the highest vacuum is reached than back up a bit ....... think it was wat they used on turbo engines
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