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#1
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im having problems getting my car to idle in gear. it doesn't want to idle in neutral under about 1100 rpm, and when i put it in drive, all it wants to do is fall on it's face. long story short:
71GP, 10:1 406, 670 heads, 220/230 @.050, 476/507 108, stock rockers, adjustable rocker nuts, what i believe to be a original torker, edelbrock 750, summit cheapie headers, 2.5 flowmasters, 2600 stall, TH400, stock rear, open/2.73 i know i need 3.73's and a posi, but that's coming as soon as i can. timing is at about 14 initial, distributor is a stock hei with all the summit internals (my summit piece wouldn't fit on the oil pump shaft) spark plug gap is .50. how important is the grommet on the valley pan as far as vacuum leaks go? the grommet was wasted, and i just went down and got a PCV style grommet that fit in the hole OK, and a generic PCV in that. that is the only thing i can think of to trouble-shoot. and ideas? |
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#2
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im having problems getting my car to idle in gear. it doesn't want to idle in neutral under about 1100 rpm, and when i put it in drive, all it wants to do is fall on it's face. long story short:
71GP, 10:1 406, 670 heads, 220/230 @.050, 476/507 108, stock rockers, adjustable rocker nuts, what i believe to be a original torker, edelbrock 750, summit cheapie headers, 2.5 flowmasters, 2600 stall, TH400, stock rear, open/2.73 i know i need 3.73's and a posi, but that's coming as soon as i can. timing is at about 14 initial, distributor is a stock hei with all the summit internals (my summit piece wouldn't fit on the oil pump shaft) spark plug gap is .50. how important is the grommet on the valley pan as far as vacuum leaks go? the grommet was wasted, and i just went down and got a PCV style grommet that fit in the hole OK, and a generic PCV in that. that is the only thing i can think of to trouble-shoot. and ideas? |
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#3
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I had 2 different modules that caused a similar situation for me. In my case it only happened when the car was hot. New module and problem was solved. In your case, I think I'd look for a vacuum leak. Plug up the vacuum line to your power brake booster and see if it goes away.
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frittering and wasting the hours in an off hand way.... 1969 GTO, 455ci, 230/236 Pontiac Dude's "Butcher Special" Comp hyd roller cam with Crower HIPPO solid roller lifters, Q-jet, Edelbrock P4B-QJ, Doug's headers, ported 6X-8 (97cc) heads, TKO600, 3.73 geared Eaton Tru-Trac 8.5", hydroboost, rear disc brakes......and my greatest mechanical feat....a new heater core.
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#4
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ok, i just went out with a vacuum guage, and noticed that my distributor is pulling full advance... both ports on the carb have vacuum. i tried getting it to idle closer to 800, i got the timing at 14, vac. advance plugged, took a vacuum reading, it's about 8. i plugged all ports on the carb, it was going between 10 and 12. i tried adjusting the idle mixture screws, but they arent doing anything because the idle adjustment is up so high so the car will idle. i back it down, and it dies. there is absolutely no happy medium.
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#5
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__________________
RDRR Custom Fabrications ....A fictitious company doing fictitious work.... |
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#6
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I have the torker one and an edelbrock 750. running the mixture screws almost all the way in and it idles pretty good after a minute of warming up. Maybe this will help you. BTW the carb is brand new.
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#7
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i pulled this carb directly off the motor that was in it before, and it ran fine before. im thinking about ditching the phenolic spacer that's on there now, and putting a regular gasket on.
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#8
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I learned of another way to check for vacuum leaks that is much cleaner than spraying carb cleaner. What you do is use an un-lit propane torch and direct it at all the possible vacuum leak spots and the engine speed will increase if a leak is present.
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#9
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Your set up doesn't seem too wild yet those are pretty low vacuum numbers. If your Q'jet idle circuit is set up for a stock engine pulling a high vacuum at idle, your low vacuum will not pull enough fuel through the idle circuit. So it looks like you are you are having to open the throttle plates to get extra fuel from the off-idle ports or even the main nozzles. Can you see fuel dripping from the main nozzles in the boosters at the top of the carb on to the top of the throttle plates?
I suspect a carb problem. Even though Q'jets are great carbs, they were ALL originally built for stock engines, so are tricky to adjust for performance cams, etc. |
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#10
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i'm not using a quadrajunk, im using an Edelbrock 750. i changed the base gasket today, and disconnected every vacuum line to the intake and plugged everything. i also was told that with the AFBs my problem might be with the step-up springs. i changed the springs to whatever other ones i had, and it made a little difference. i don't know what i had in or what i put in, but now, it idles at like 1200, when i drop it in gear it kinda idles at about 500, but it isn't happy. when i turn on my electric fan, it kills it, even in park.
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#11
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I feel like # 5....input..., need input, need more input!!!
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RDRR Custom Fabrications ....A fictitious company doing fictitious work.... |
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#12
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Hmmm, defnitely sounds like a vacuum leak. If you can't find the source externally you might want to make sure your intake manifold is sealed. If thats not the problem I'll betcha you have a valve or two adjusted too far down and isn't closing all the way.
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"Man did not weave the web of life, he is merely a strand in it. Whatever he does to the web, he does to himself." - Chief Seattle |
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#13
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ok guys, get some popcorn... i bought this engine from a guy that had it in his circle track car. it's a 67 400 with 670's and the torker manifold (i think thats what it is, all the stuff has been ground off.) it had been sitting for 6 years in the garage(with new oil, and no rockers or studs, so no strain on the springs.) i bought it, and planned on going through it, putting forged rods and crap, but a week after i bought it, the camshaft eccentric self-destructed on the motor in my car. ok, either pull the motor out, pull the pan, fish out the chunks from the eccentric, or re-gasket the motor in the garage. i pulled the heads off the "new" motor, and everything looked great. no grunge or anything inside, i could still see the hone marks in the cylinder walls. i ordered the good performance felpro gasket set from summit, and i had already ordered the RA4 intake gaskets, as i was going to port the heads, but i had to get the car running. i put all the new gaskets on, and when i got to do the intake, i found that the stock-style gaskets didnt work, and the RA4 gaskets fit better on the head than the others(670 heads, origional torker man.) i just used the RA4 gaskets, put everything together, got it in (that was a nightmare too, motor mount adapters suck) parts i took off my other motor are: carb, took internals out of summit HEI, put in the distributor that came with it, seeing as how the summit one didnt fit, headers, water pump, pulleys, and that's about it. fired it up, and i was chasing a really annoying tapping. pulled the valve covers, did a compression check, and every hole on the driver's side was 45-50 psi. passenger side was 100-125. something was definately wrong, went to adjustible valvetrain, noticed that some of my lifters seemed excessively soft. replaced the lifters, adjusted the valves 1/4 turn past no ticking, and ran with it. it ran much better, and there was a visible difference in how much the rockers were moving. tapping is still there, but it doesnt sound like a rod knock. i really dont care about the noise right now, it runs pretty well, its just annoying, my problem now is getting the thing to idle. i tried changing the step-up springs last night, and whatever i did made a difference, but i don't know whta i had in or what i put in, so tonight i went and bought the assortment, so i know what i'm putting in. that's my project tonight. a friend of mine also suggested drilling an 1/8" hole in the throttle blades so i could get the idle low enough that the idle mixture screws will do some good, what do you guys think. are those enought details?
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#14
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I WAS WONDERING...WHAT INTAKE GASKETS ARE YOU USING...I JUST BUILT A 68 400 ENGINE AND INSTALLED IT IN MY FIREBIRD..MY PROBLEM SOUNDED VERY SIMILAR...I INSTALLED AN EDELBROK INTAKE..BUT I USED THE INTAKE GASKETS FROM A FULL ENGINE REBUILD GASKET KIT...THOSE INTAKE GASKETS JUST DIDNT FIT CORRECTLY...IT SEEMED LIKE A TERRIBLE VACCUUM LEAK...I TRIED EVERYTHING...I CHANGED THE INTAKE GASKETS TO THE RECOMENDED FEL PRO HIGH PERFORMANCE GASKETS AND NOW MY BABY PURRS LIKE A LION...MAYBE THAT WILL HELP...I KNOW IT REALLY SUCKS WHEN YOU BUST YOUR BUTT ON A PROJECT LIKE THIS AND ITS JUST NOT RIGHT........GOOD LUCK
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#15
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i tore the heads off my other motor tonight, and the intake gaskets on there are the same as the ones i put on the new motor, so.... who knows?
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#16
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ghettosled71
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>and i was chasing a really annoying tapping. pulled the valve covers, did a compression check, and every hole on the driver's side was 45-50 psi. passenger side was 100-125. something was definately wrong, went to adjustible valvetrain, <HR></BLOCKQUOTE> <BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>it ran much better, and there was a visible difference in how much the rockers were moving. tapping is still there, but it doesnt sound like a rod knock. <HR></BLOCKQUOTE> Your engine should have 160-170 psi if it's 10:1 CR. What your discribing, to me anyway, is a worn out cam. If you have the heads off check the lobes of the cam before you reinstall the heads.
__________________
"For some reason a glaze passes over people's faces when you say "Canada". Maybe we should invade South Dakota or something."
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#17
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when i replaced the lifters, i checked out all the lobes, and everything looked pretty good to me. one thing that seems wierd to me is the fact that when the car is idling (or trying to) the carb whistles really bad. before, all i could hear was is sucking, but not like this. i dont know what the deal is with that, but someone told me that id be better off with a holley, and i think i found one, but i still am not sure if that'll solve my problem. i would replace the cam, but if that doesnt solve my problem either, it's just taking money out of the new-motor-with-forged-pistons-and-rods fund, and that fund is growing slow enough as it is...
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#18
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ghettosled71
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> timing is at 13/14initial, and it's kindof jumping around, might be from the high idle/vacuum advance kicking in, but i dont know. <HR></BLOCKQUOTE> I was looking on another post of yours about the problem your having. Are you disconecting the vacuum advance when you set your initial timing? If not, this could explain the problem your having. The vacuum advance wouldn't have an effect on your initial timing unless you were checking the timing with it hooked up.
__________________
"For some reason a glaze passes over people's faces when you say "Canada". Maybe we should invade South Dakota or something."
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#19
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part of my problem, i know, is that the ported hole on the carb is pulling full vacuum ALL the time, and i can't get the throttle blades closed enough that it will stop. if i get it down that low, it dies before i can do anything. also, with the blades being that far open, the idle mixture screws don't do jack.
so, yes, when i check the timing, everything is disconnected from the carb. when i checked the timing the first time, the vaccuum was hooked up, it was at like 50 degrees. |
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#20
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So then use manifold vacuum. You need to work on your idle circuit. It needs more idle bypass air. A quick fix would be to drill a small 1/16" hole in the throttle blades so you have more control of the idle mixture screws.
I have a Qjet on mine (462) and I drilled the holes in the throttle blades. It helped big time. I've since opened up the whole idle circuit and idle air bypass. The carb has no issues and is very responsive from idle to "good by rice boy"
__________________
"For some reason a glaze passes over people's faces when you say "Canada". Maybe we should invade South Dakota or something."
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