cant make my car idle mystery need gurus

Old 06-05-2009, 08:56 PM
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olds48
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Default cant make my car idle mystery need gurus

Hey guys. Been awhile. I need ya'lls help. I should be able to figure this out on my own,but apperently I have forgotten the basics. Two weeks ago I was driving my Pimpala and the throttle stuck momentarily,( didn't concern me much since the temp sensing wire has a tendacy to get in the way occasionally,I know,I know....should fix it,anyway) i tapped the throttle and it was fine. I was in town and headed to a buddy"s house to grab a spare tire and some tools to help another buddy who had a flat(another story in itself).Well, i went on and grabbed the stuff and went on and drove to the other side of town...30 minute in-town drive...no problems. Changed the tire,hopped on the interstate and started booking it back to the country.....20 miles of highway...no problems. Got off the exit ramp and the car died. Just like you turned the key off. ??? Weird,car has never done that.Started it up,and it was fine.Pulled up to the traffic light,waited for it turn green,it did, took off up the highway...no problems.Went about two miles and the car started knocking/clattering like MAD!!! Glanced down at the oil pressure real quick,it was fine, and shut it off instantly. Thank God I was able to coast into an empty car wash,about 11:30 at night. That's when me and my girlfriend took a moment of silence for "The Great Pimpala Travesty".................. I called my neighbor,and best bud, he grabbed his truck and my enclosed and was on the way. Thank God for bud's that are night owls While I was waiting(readouting :cry: ) I popped the hood to console the car and noticed my air cleaner had rotated around backwards. Odd. Let me just spin that baby around and tighten the stud down.....where's the stud?...where's the stud.....WHERE IS THE STUD?!?! Yep,ya'll know where it went. Number 7 intake valve. Guess we know what caused that pesky throttle hiccup,too,huh? Well, next day i pulled the intake and the stud was poking out and I extracted it. Pulled the spring off that valve.....and it was fine !! Did a leak down test...fine. Moved the valve up and down and twirled it in the guide...fine. Borrowed a friend's bore-scope(very cool snap-on toy with color screen...nice) and took a peak at the seat...fine. Push rod is fine. Put the spring and all back on,did a compression test...fine. Everything checked out fine!! Went ahead and put new cap,rotor,plugs and wires on since the engine has right at 50,000 miles on it and I have never touched it since I put it in the car.Started it up and it won't run for crap. Had to jack the idle screw up a turn and a half just to keep it running the set the timing.Got it set fine. But now the car idles rough(though it does sound wicked :twisted: rumpity,rumpity,rumpity...)wants to foul the plugs(all 8) and is not responsive at all. got to ease into it to bring engine speed up,and then it returns to idle real slowly. Thought it might be a vacuum leak,but checked all mating surfaces with starting fluid and it seems to be fine. I have double and triple checked everything from distributor phasing to valve adjustment(which I didn't fool with prior,but all is fine),but apparently have overlooked something. Pretty bad when you can't even pull an intake and set it back on without problems ops: So there it is with all the details(probably too many) I can think to give you. She's broke and I'm sad. ANY ADVICE GREATLY DESIRED!!! Sorry for rambling,been awhile since I been on here so I guess I'm just making up for lost time. Ya'll still awake?...hello?...uh...zzzzz....ok...later
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Old 06-05-2009, 09:10 PM
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cepx111
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Good to see ya back, but Hmm, only comes around when he needs something, reminds me of my a$$hole brother.....lol > J/K

Sounds like you just about covered everything there bud, I do have a few suggestions though.
I had one do something similar to me one time and it was a loose wire on the HEI dist, the big orange "key on" wire was loose, pulled it off shoved back on, problem went away.

Also did that stud bugger up the carb any? I'd yank the carb off look at the transfer slots and butterflies and blow the thing out just for $hits adn giggles, maybe some thrash got in it while you were pulling the intake.

Just a FEW thoughts, Welcome back Popeye> Cp
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Old 06-05-2009, 09:20 PM
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olds48
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Hey big guy! Good to talk to ya. I know,you're right.Only here because I need something :lol: Good point on the carb.I'll do that. When you say big orange key,what do you mean? They harness from the dist base to cap??It does have an hei on it
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Old 06-05-2009, 10:19 PM
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the way the engine comes down from an idle I would check the for a lean condition. First check the big vacum port in the back of the carb. Next I would bring the car at a fast idle and check for gas dripping at all four boosters. The last thing I would check would be the firing order espically the, 5 and 7 plug wires i have crossed these before and the car still runs but does not idle. next is pull the spark plug and check for oil (cracked pistion) or a closed gap (left over junk in the cylinder).

After all else fails the next thing I would suspect is a bent pushrod or bad lifter damaged by the pistion contacting the valve when it was stuck open. Because if the intake valve opens too early or is opened slightly, exhaust will enter the intake manifold and cause a lean condition. A bad hydralic lifter can still give you good compression readings

Ive been there too,
hope this helps
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Old 06-05-2009, 10:38 PM
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olds48
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Thanks steve. The valve and seat seemed to be fine when I had the bore-scope in there,but that doesn't mean everything. Will a bad hydraulic lifter really give a false reading? didn't know that. Always wondered about that,though. Hows does it have enough oil pressure at such a low rpm to operate correctly? I'll check it out. Thanks brother
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Old 06-05-2009, 11:26 PM
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cepx111
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Originally Posted by olds48
When you say big orange key,what do you mean? They harness from the dist base to cap??It does have an hei on it
Eric, I was refering to the "Key on" hot wire on the HEI, it's usually orange, sometimes red, it says BAT where it connects on the cap. Anyway pull it off and shove it back on a fews times to make sure it's getting a good connection, can't hurt.


And what the hell have you been doing that keeps you so dam busy that you could pop in and say wtf to your RJ buddies?

Good to have ya back, Cp

Hey I got a problem with my car, it's been smoking really bad, any thoughts?












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Old 06-06-2009, 01:02 AM
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Hey Eric Where ya been??
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Old 06-06-2009, 09:19 PM
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Wassup Charlie,how you been. Got no good excuse. Mixture of too many friends needing favors,woman wants to go out,car needs work and I need to make a dollar.What you gonna do? How it's been Earl? The mighty Fiat sure does look good! When you gonna let me make a pass in the little booger?! :lol: Hey,I found my problem. Noticed the passenger side exhaust sounded funny,like a burnt valve. So I decided to run a compression test again. I had done one already and had 200 psi on every cylinder...except the #6 cylinder. The way the a/c compressor mounts and that header tube hooks around,it is impossible to get at without removing stuff. So I jerked the compressor and header off and guess what? Yep,plum dead. Seems the stud went into that cylinder,bounced around,boogered up the piston,bent the valve,decided it hadn't had enough fun, and moved to the OTHER side of the motor to lodge it self in the #7 intake valve. #7 is fine.Gonna have to weld up on my head and have a new valve,seat and guide put in,but the piston seems fine. Just superficial dents and scratches. It's got hyper pictons,so I don't think it would have cracked it. What do ya'll think? Weird though,when the valve bent and it went to close,it just pulled the guide up with it! That ticking noise I was telling ya'll about was the retainer smacking the guide! :lol: :lol: I think I can reuse the valve seal though :shock:
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Old 06-07-2009, 09:16 AM
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If any of the dings in that piston are anywhere close to the edge you need to pull it out. Usually it pushes the top of the ring land down enough to pinch the ring.
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Old 06-07-2009, 01:00 PM
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olds48
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Good point,Chuck. I was only thinking of piston to cylinder wall clearance. Glad you mentioned that. Thanks. Throw out bearing is a little noisy at times,so probably best to jerk the motor and get that piston out.
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