03-08-2012, 10:06 AM | #1 |
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RPM- Iddle issues
1970 C10 p/u 350 5.7L with a performance cam, edelbrock 600cfm carb, Timing set at 12 BTDC.
My issues is this: In park idle is runs about 900 rpms. I let it warm up to optimal operating temp and once I shift to reverse the rpms dramatically drop to 300 or so for a bit before it comes up to 500. Once I get going it runs well. BUT when I come to a stop light the RPMs drop to about 300 and the truck sounds like it wants to stall before it kicks itself back up to 500 rpms. I have checked timing, vacuum leaks, accelerator pump, jets, springs, spark plugs/wires and so on. I am at a loss as to what I need to do next. PLEASE someone help. |
03-08-2012, 11:13 AM | #2 |
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Re: RPM- Iddle issues
What size "performance cam"? Is the converter matched to handle the rpm range of said camshaft?
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~Jon Ol Green 1970 K10ish LWB,454/400/205, been in family since new.
My build thread http://67-72chevytrucks.com/vboard/s...d.php?t=516056 |
03-08-2012, 12:15 PM | #3 |
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Re: RPM- Iddle issues
Modulator valve in the transmission. (?)
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Chad 1967 C10 SWB - Project Savannah - 6.0/4L80 *Currently underway* 1968 C10 SWB - TOTY 2018, 50th Anniversary Tribute Project * Sold * Pride and Joy 1986 Silverado Short Fleet - Scarlet *Sold* 1985 Silverado Short Fleet *Sold* 2022 Jeep Gladiator Mojave 2001 Jeep Cherokee XJ 4x4 - Lifted, Built 1992 Jeep Cherokee XJ 4x4 - Lifted 2013 Honda Accord EX-L v6 Coupe 6spd (wife's ride) |
03-08-2012, 12:28 PM | #4 |
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Re: RPM- Iddle issues
Lower,
The cam was specially made and grinded for my truck. I am not sure of measurements BUT it was all installed when the engined was rebuilt. I know for sure that the converted is made for the engine and cam. |
03-08-2012, 12:30 PM | #5 |
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Re: RPM- Iddle issues
This whole issue started after I had a mechanic install a new intake (edelbock air gap dual plane intake) I am wondering if maybe he did not install the distributor correctly when the engine should have been at TDC??? COuld a misaligned dist. cause this type of issue?
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03-08-2012, 12:31 PM | #6 |
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Re: RPM- Iddle issues
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03-08-2012, 12:40 PM | #7 |
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Re: RPM- Iddle issues
If you checked the timing and it is ok then the dist is probably fine, did he get the vacuum lines to the trans and the dist hooked back up in the right places?
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~Jon Ol Green 1970 K10ish LWB,454/400/205, been in family since new.
My build thread http://67-72chevytrucks.com/vboard/s...d.php?t=516056 |
03-08-2012, 12:43 PM | #8 |
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Re: RPM- Iddle issues
@Lower
Yes, but I asked him a few days ago how he adjusted everything and he stated that he could not see TDC and so I am not sure if he put the dist in without it being aligned properly. |
03-08-2012, 01:02 PM | #9 |
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Re: RPM- Iddle issues
If you know how to find TDC, roll it up there and pull the cap and see where the rotor is pointing.
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~Jon Ol Green 1970 K10ish LWB,454/400/205, been in family since new.
My build thread http://67-72chevytrucks.com/vboard/s...d.php?t=516056 |
03-08-2012, 04:45 PM | #10 |
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Re: RPM- Iddle issues
Try putting ported vacuum to the vacuum advance & then turn the idle speed screw up till you get about 800 rpm idle speed in neutral.
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