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  #1  
Old 09-13-2001, 02:34 PM
SubLime440 SubLime440 is offline
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Default This is frustrating.... What's wrong?

Okay... I have 2 cars and they both seem to have the same problem... The '72 Cuda 440 starts and runs great until it gets hot (210 or so)... It's a drag only car and when it wins and I virtually have to hot lap... It won't start... It turns over fine (New Mini-High torque Started) but won't fire... Once it cools down it fires up again right away... I've check mag pickup gap in Mopar Distributor and have tried differents settings to no avail...it gets fuel fine from fuel cell... I've put in an MSD adjustable timing pot (8680) to retard timing and still won't start...(Has MSD 6AL) It seems to flood ... The only way I can get it started is by holding accelerator pedal to the floor and eventually it starts to fire... I am running a Holley 850 DP on a Edelbrock TorquerII manifold...Of course when everybodies waiting for you in the staging lanes, it gets very frustrating... Again this only happens when it gets hot....

My '70 Challenger 440 does a similar thing, once it gets really hot it doesn't like to fire ... I have an MSD Pro Billet Distributor / MSD 6AL... Holley Blue pump set to 7psi... and it does the exact same thing at high temp... Car normally fires right up on first turn but get the thing hot and it fires when I hold down the Acclerator pedal to the floor...eventually...I'm even running a 1" spacer on this carb...

Any guesses...to why this might be happening?
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  #2  
Old 09-13-2001, 02:57 PM
Mr. Trans Am Mr. Trans Am is offline
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Sounds like you need to look at the carb first as it fires when you "clear" it. Floats, needles?
If they come through w/ a clean bill of health I would look very seriously at those MSD boxes. I have seen multiple problems associated w/ those boxes and I'm not sure why people seem to want to run them exclusively. Very strange stuff.

Also swap ecu box. I had a truck that would leave me sitting. Would crank away, no fire, would start later on. Chased down the ecu and not only put a new one on but also ran a ground wire from it to the battery. Those need a good ground to operate, don't underestimate that. I have had zero ecu troubles on all 5 of my mopars since running that ground wire. Hope this helps.
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  #3  
Old 09-13-2001, 03:10 PM
SubLime440 SubLime440 is offline
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Checked float levels and set them right on through sight plugs...fuel in just a hair above bottom of sight plug...
Both cars run MSD 6AL boxes... Cuda has MP Distributor with blaster 2 coil and Challenger has MSD Billet with Blaster 2 coil....
Again they both fire up fine until they get very hot... Carb on Challenger is brand new... I must say that the Cuda problem seems worse though... I have confidence in getting the Challenger to fire up... The Cuda is a crap shoot when it get's hot... I'm guessing that it's carb related but why when it's hot only? Do I need an insulator spacer on the Cuda? I have no complaints with these cars at all until they get hot? Is this a common problem???
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  #4  
Old 09-13-2001, 04:28 PM
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Hammer 74 Hammer 74 is offline
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After you shut them down hot, look down the carb to see if fuel is percolating out of the vents or acc. pump. Are your fuel lines routed away from heat sourses. I used to wrap my fuel line with water pipe insulation from the hardware store. Also I routed the lines as far from the block and headers as possable. Sounds like vapor lock. Just an idea.
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  #5  
Old 09-13-2001, 04:37 PM
SubLime440 SubLime440 is offline
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Could be vapor lock I guess... Fuel lines are routed and protected as far away from exhaust system as possible... I feed in from the back of carb and fuel lines stay cool.... I don't believe there is a problem with the lines themselves....
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  #6  
Old 09-13-2001, 05:23 PM
beeman beeman is offline
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Default Won't start when hot

Check out coil. Mine did same thing when hot, work great when cold. Coil output would die only when hot.
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  #7  
Old 09-13-2001, 05:25 PM
11secB 11secB is offline
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Default i had the same problem

I had the same problem with my 383. I was using a
eldelbrock carb and every time it got hot youit wouldnt start unless you held the pedal down(wide
open) What was happening to me was the carb was getting hot and perculating (bad spelling lol) I put in a heat protecting spacer and havent had a problem since. I hope your problem is as easily fixed. Big block mopars create a lot of heat and if the cooling system isnt operating at 100% they can cause many fuel problems. GOOD LUCK
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  #8  
Old 09-13-2001, 05:38 PM
SubLime440 SubLime440 is offline
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I run the 110 Purple fuel in the Cuda and a mix of Premium Unleaded and 110 in the lower compression Challenger... Both have similar fuel systems (Holley fuel regulators) ... Cuda has fuel cell and Challenger has regular tank... I believe the carb is flooding as well, but didn't know why... I used to have problems with backfiring through the carb (Both power valves plugged too).... Timing looked good... (Put the MSD timing retard pot in to assist starting...) I was running batteries down trying to get the thing started and went to the High Torque mini-starter and it worked wonders... No more backfires and car seemed to start right off... but then last weekend the darn thing started winning again...darn it... So the car was virtually hot lapping and running pretty hot...I was again faced with it not starting in the staging lanes... (Eventually ran battery down) and had to jump it down by the waterbox.... Both cars running Holley Blue Pumps... So A70Duster your're saying you've seen this problem? I do believe it is getting spark as the tach does move... but I will check plugs...Man I was pissed last weekend too when this thing started acting up... After everybody was waiting for the car to fire...it did and then a "Redlight" ... Car and Driver error!
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  #9  
Old 09-13-2001, 05:48 PM
SubLime440 SubLime440 is offline
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Sounds like my carb might be a coffee pot....
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  #10  
Old 09-13-2001, 06:35 PM
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Default Just an idea

This doesn't cover any of the fuel system problem's discussed, but, I know from experience at the dealership, on the 70's cars, the Mopar pickup plate can move through a continuity/no continuity with heat/hot soak. It would be REAL unusual to have both cars doing it, but not completely out of the question. As has been mentioned, check for spark when in fault condition. Now about that red eye!
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  #11  
Old 09-13-2001, 11:51 PM
PRO PRO is offline
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Holding the gas pedal down opens the butterflies and allows a ton of air to enter the engine thereby leaning out the mix,I ve had a rash of bad needle and seats in NEW holleys lately,today in fact my 830 did it on the way to work and has about 60 mi on it,the rubber tip of the seat had a little extra rubber overhanging the brass,this went up between the seat and needle,also set your fuel level 1/8" below sight plug because it will fill higher when hot or percolating,hope that helps.......PRO......
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  #12  
Old 09-14-2001, 06:23 AM
JCFcuda JCFcuda is offline
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Wink

How about your timing?When you somtimes have it adavanced, it will not want to start .Does it want to fight the starter?
Jim
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  #13  
Old 09-14-2001, 06:58 AM
warlockpowerwagon warlockpowerwagon is offline
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I tend to agree with PRO, I set my holley with fuel just barely even with the bottom of the sight plug, not worrying if it is a little lower. I can idle the car with the sight plug removed and no fuel will flow out. This is how I like the adjustment, no flooding and no running out of fuel at wot.
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  #14  
Old 09-14-2001, 09:38 AM
SubLime440 SubLime440 is offline
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Interesting.... Needle and seat.... I could see that... As far as setting the fuel level... I can adjust the float level down, but I know many people I race with that put their level in the middle of the sight plug... I think that's too high, personally....anyways, as far as timing goes, the car "does not fight the starter" it is advanced at 38 degrees in total and I even put the Timing Retard Pot from MSD on the 6AL so that I could dial the timing down if that became a problem... I can set the thing to whatever and the car WILL NOT FIRE when hot... and yes the Timing Adjustment device does work when car is running... I believe it is in the fuel system and I have a lot of ideas now... Thanks!
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  #15  
Old 09-15-2001, 01:06 AM
dewme5 dewme5 is offline
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i could be wrong, but i doubt that barry grant is. for street use, fuel should be at the bottom of the sight glass. drag racer. in the middle, and for oval track use between mid and top.
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  #16  
Old 09-15-2001, 09:09 AM
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340MAN 340MAN is offline
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i had the same problem & also run msd 6al on all my vehicles.
the engine gets hot it perculates the fuel. if your fuel levels are too high, it will push out into intake & flood.
reset fuel bowls to when engine running below bottom thread on sight plug & used a phenolic spacer. wrapped the fuel line as soon as it enters the engine compartment. ran my toal timing @ 36 dgrs & this stopped the bucking & having to worry if its going to crank propblems.
also, an aluminum rad & hvaing someone be your pit help by having a large yard sparayer full of water handy is another trick on hot days. spary the water in frt of rad before shutting dwn.
lots of luck
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  #17  
Old 10-01-2001, 09:20 PM
SubLime440 SubLime440 is offline
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Spacer under carb did nothing.... Put my MSD Billet distibutor in car and wallah....

Car started fine everytime with the distributor from my other car... Ran 2 days with no starting problems and no backfires... (Although the car did not run any faster or slower in the 1/4 mile)... At this point the Distributor seems to have been the problem...!!!!
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