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Car dies when accelerating -- idles ok

Old 08-27-2010, 11:34 PM
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Car dies when accelerating -- idles ok

Hey guys,

I've got a wierd problem that I'm hoping you can help me solve.

The car is an 84 T/A with a mild-build 355, CCQjet (built for a stree/strip car), 700R4.

Three days ago I got my carb back from having it rebuilt by a professional builder to have the carb handle less vacuum, more power etc (Bigger needle and seat, larger primary rods, larger secondary rods, recalibrated idle and off idle etc). Guy by the name of Cliff Ruggles did it.

FOr three days in the driveway it idled and ran awsome. Took it on the side streets around the house and I put about 30 miles on it then decided to put it on the freeway to take it to the store some 12 miles away. Stop light to stop light, it ran awsome. Then about 4 miles on the highway I decided to let her rip, shifted down and hammered it. Lets say I buried the needle and hit 5 grand on the tack. Taking my foot off the throttle the car came back down but didn't sound right. The best I can describe it is the car "flatlined"...it didn't "rev down" like it normally does. Eventually it kept slowing down. Every time I pushed on the throttle i'd get this "flat line" response. the car would initialyl surge, but then just stop, no acceleration, just dead...nothing unless I fluttered the throttle.

I eventually limped it home this way (talk about embarassing...) Anyway, I thought it was fuel or lack there of because my fuel line gauge red 1-2psi. So I ordered a new holley black pump. Got that installed, checked for leaks, set the pressure to 7psi, and fired her up. Fired up perfect, choked kicked in, idled up to 1500, then died. Started her again, started fine, idled up, then died. Feathering the throttle I can keep her running but barely. Ruins "ok" near idle speed but as soon as I give her throttle she bogs really bad and dies unless I feather it. I checked for good spark, all cylinders firing (though I can't really check when i'm on the throttle). Thinking maybe I broke another valve spring I checked the vacuum which was strong and steady at 12" on idle. Whenever I hit the gas the gauge would go up a little then drop like a rock. Anything 1500 and over she studders really bad and sounds like cars do when they hit their rev limiter then dies. I can hear what sounds like a hissing or exhaling sound from the carb if I keep my foot on it till she dies. When I do this the vacuum gauge drops to 0. if I take my foot off and feather, she'll come back and idle pretty well.

Does this sound like a ignition or vacuum problem? what got me is it ran great for 30 miles before this happened. Really strong pulling in traffic and from stop lights through all gears. I'm at a loss. I really thought of a vacuum leak but no deflection what so ever on the vacuum needle. Strong and steady. Could my dizzy be bad? any ideas on where to start would be greatly appreciated, thanks!
Old 08-27-2010, 11:41 PM
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Re: Car dies when accelerating -- idles ok

Sounds more like a fuel problem.
Old 08-28-2010, 02:51 AM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Sounds more like a fuel problem.
Old bad gas? The car did sit for 8 months. I parked it in October, then it sat from Feb - Aug while waiting for the carb to be rebuilt. It was just above "E", filled it up right before I took off. I've got 20 miles on the new tank according to the odometer.
Old 08-28-2010, 02:53 AM
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Re: Car dies when accelerating -- idles ok

Not a quality problem, a delivery problem. Something obstructing flow to or within the carb.
Old 08-28-2010, 02:56 AM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Not a quality problem, a delivery problem. Something obstructing flow to or within the carb.
Well, I know for a fact it ran like a scalded dog for the first 30 miles. Coming out of the regulator (My fuel pressure gauge is inline just after the regulator) I have 7psi.

I suppose I could pull the filter (didn't think of that till now) to see if it got clogged. I"m only running the single filter that is in the fuel entrance of the Qjet, I've got no other filter. Cliff (He actuall wrote a book on how to rebuild these) said that he dynoed it on one of his 383 dynoqueen motors that he tests stuff on to make sure everything worked well. I've no reason not to believe him. Any idea's where to start?
Old 08-28-2010, 03:58 AM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Sounds more like a fuel problem.
Pulled the filter and there was a little gasket that had slid down in front of the filter opening....or so it seems. I took it out and when I turned the key to check my fuel pressure, it dropped by 1 to six, but fuel started coming out of the top of the carb. I backed off the fuel pressure a bit but now the car won't start. It turned over twice and locked up. Severely flooded? Pushed raw fuel over the secondaries and down into the intake? I'm going to let it set for a bit and try again. Hopefully I won't catch anything on fire. lol
Old 08-28-2010, 04:10 AM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Not a quality problem, a delivery problem. Something obstructing flow to or within the carb.
Ok, got her to fire up. That was odd. Anyway, it idles pretty good now. However, every time I push on the gas and the RPM's hit about 1500, I get a hissing sound from the carb area and the car dies as the vacuum gauge drops to 0. It's like I'm losing too much vacuum before I can pull enough fuel? Only if that were the case eventually it would move over to the primary side of the carb and we'd be money. I had the carb built specifically so it would handle that issue...the one of lower vacuum because of my new cam....wierd. Anyway, It's 3am now and I'm tired of messing with it today because I can't t hink anymore.

Last edited by Ozz1967; 08-28-2010 at 04:18 AM.
Old 08-28-2010, 04:35 PM
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Re: Car dies when accelerating -- idles ok

Double checked the fuel filter, looks clean. Replaced the element anyway, same issue. I know the carb is running rich, I haven't had a chance to "dial it in" yet to my engine. Could a clogged cat be doing this? I had a new cat put on a year ago when I swapped the engine in, so I wouldn't think that's it but...I'm running out of ideas here.
Old 08-28-2010, 04:44 PM
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Re: Car dies when accelerating -- idles ok

Did you get any warranty with your carb?
Old 08-28-2010, 11:23 PM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Did you get any warranty with your carb?
I don't know. I"m going to email him all the corrospondance here without indicating anyone else gave any imput to see if has any imput to add. I suppose worst case I ask to send it back to have him double check it and wait a couple weeks for the turn around plus shipping times.
Old 08-29-2010, 12:46 AM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Did you get any warranty with your carb?
I really don't want to contemplate it being bad....not after waiting 6 months for it to be built. The car will have been parked a year come October 1st if I don't figure this out.
Old 08-29-2010, 10:19 PM
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Re: Car dies when accelerating -- idles ok

Don't worry, some cars sit for years at a time.
Old 08-29-2010, 10:31 PM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Don't worry, some cars sit for years at a time.
Yes, this is true, however, my wife isn't as understanding as this was my DD prior to the engine swap. She cant quite wrap her brain around ''project car''.
Old 08-30-2010, 04:44 AM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Don't worry, some cars sit for years at a time.
Ok, some good news. Not exactly sure what changed, but the car starts and idles fine. I was checking the fuel pressure and manually ran the throttle under the hood and cranked on it pretty good...no cutting out, not stalling. The thing sounds like it's sucking air pretty good through the primaries.

I pulled it out of the drive way and took it for a test drive. The idle is low, really low. IN gear the tach reads 500 or a little less. I'm going to bump that up to 600-700. When I throttle up, it does stumble a mid throttle....then takes off. If I hold my foot stead on the acellerator, it doesn't want to keep going...I get the "dead spot" that I had before when idling. Sounds like the car is gasping, it will hesitate and stutter, and will die if I don't feather the pedal just a bit. Then takes off and runs fine when I keep my foot in it. Makes driving really herky-jerky. Almost an Idle to "GO"....situation. But, it's drivable. Sort of. Which is an improvement from not staying running.

--Ok, update from the drive home from work.

The car starts and idles fine. Running rich, but I can deal with that. Giving it gas it stumbles, stalls a little, but will go with feathering the throttle. Or, it will just GO, then sort of fall off if I keep the throttle steady, then sort of catch itself, and GO again. If I get it going then when it stalls if I put it to the floor, it'll sort of stumble to 2000rpm then suddenly launch full throttle. The common theme is, if I keep the throttle steady, it'll die. If I get it to go full throttle, it'll run all the way to 5k+ with no hiccups...unless I ease back on the pedal trying to keep it steady...then it'll want to die again. Pressing the pedal down causes it to stumble as it tries to accelerate. This is so wierd.

Last edited by Ozz1967; 08-30-2010 at 09:52 AM.
Old 09-06-2010, 04:47 AM
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Re: Car dies when accelerating -- idles ok

Originally Posted by Apeiron
Don't worry, some cars sit for years at a time.
Awsomeness!! (is that a word? I don't care!) Ok, well, after a little digging, on the site I found some info. And so I dug some more. I went searching. And searching. And searching. And I found that ails me! It seems that if the lean and rich stops aren't set correctly, this can have an issue on the part throttle and idle stability. So, after some more searching and talking to a friend and some beer (probably not the best idea but hey, it worked out), I went and adjusted the lean and rich stops. Three turns down from the upper limit on the rich and 5 turns up from fully seated on the lean. Not only did the code 44 go away, but it's running great. Pulled it out and drove it around from 20-40mph all around for about an hour and just marvelled at having my car running well again. It's amazing what a mostly properly tuned carb will do for an engine! LOL Now if I can just figure out this code 43 I'll be great!
Old 09-13-2012, 04:40 PM
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Re: Car dies when accelerating -- idles ok

I have the same issue except for the fact that mine is a 91 with a 3.1 and fuel injected
Old 10-09-2012, 08:36 PM
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Re: Car dies when accelerating -- idles ok

@hahnzy1973 , did you ever figure out the 3.1 problem?
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