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Discussion Starter · #1 ·
I am not having fun today !
I have 69 Cutlass with 350 and Dual Jet .
While driving, car lost power and started running roughly, barely able to accelerate past 30mph . Also, there were popping, clunking noises coming from back of an engine and person in the back seat said it felt like something is banging under the seat.
I got home, let the car cool down and it started fine and was running ok in Park when I've pushed gas pedal . When I drove it it was having same problems as described above. I suspected ignition problem and put in new backup distributor . I started the car( run roughly ) , set idle speed and started to adjust dwell and was about at 25( needs 30 ) when car just stalled.
When I've tried to start engine, small flame came out of carb. I have tried severall time to start it but no luck( fuel air mixture shot out of carb everytime )
I am puzzled. Carb is two week new, didn't have any problems with it . Is it carb problem or ignition problem ? Can someone solve this ?
Thanks.
 

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Discussion Starter · #4 ·
Grass 1
Carburetor is new, but friend of mine was changing spark plugs on it and put BOSCH plugs, correct ones according Bosch catalog but gap is 036, manual says 30. could that make a difference and car would run lean? Will the lean/rich adjustment on choke made any diference ? I was able to start the car and is running good in park, but under the load it looses power . Would clogged idle cicuit made it run rough in park ?Fuel filter doesn't look dirty, but I will change it .

Poncho.
If timing chain jumped tooth would it sbe running smoothly in park, just idle ?

Thanks guys
 

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Olds 69 said:
Grass 1

Poncho.
If timing chain jumped tooth would it sbe running smoothly in park, just idle ?

Thanks guys
\

It might...there is little load on it. In park and you rev it up, does it backfire?

Whenever it backfires through the carb as you said, there is a plug firing when an intake valve is open.
 

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Discussion Starter · #6 ·
In park it doesn't backfire when I rev it, only when I drive . I just went around the block and it was running good for a few seconds, then it felt like it shifted( but didnot, just felt like that ) and then it started back firing again so I parked it and revved it and it run smooth .
When it was happening the first time , I never went over 40 mph all day. How do I test for jumped tooth on timing gear ?
 

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Probably not the chain if it ran good for a few seconds under load.........

Maybe running out of gas, fuel blockage, fuel pump...

May also be a timing problem, spark jumping around inside cap etc.........when you changed the distributer, did you change the cap, rotor and wires?
 

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Discussion Starter · #8 ·
I changed cap and rotor about 500 miles ago, point and condenser were new with distributor, I will get new wires tomorrow and change cap and rotor in steps so I will know when ( or if ) things change.
Just out of curiosity, how do you tell if timing chain jumped a tooth ?
Thanks for helping me.
 

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Bring your #1 piston to top dead center...0 on the timing mark. Take your dist cap off. It shpuld be pointing toward #1 or #6 wire, depending on which compression stroke you are on. If your timing is set right, they will line up....If the rotor is aiming somewhere else, the chain has jumped.

That is the easy way. The best way is to take it apart. Usually, it won't run if the chain has jumped.

To check for loosness in the chain, take your dist cap off. Turn the engine by hand one way, then the other. Look and see how quickly the rotor moves when you go in the other direction. That will tell you how loose it is.
 

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Not trying to hi-jack the thread but I have something very simular I'm dealing with on a chev350 I got an Edlebrock 600 engine starts ok for the most part but I'm gettting a hell of a flame when I try to open the secondaries. I've rebuilt the damn thing and it ran great on the other engine it came off of. I'm gonna double check the timing and I suspect it's gonna be there but any other sugestions as to why the BBQ?
 

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Backfiring from the carb usually indicates retarded timing or a lean mixture. I would check the fuel pump to see what kind of fuel volume it will put out. While your at it check fuel sample for water. Could also be a plugged fuel filter. You might check for a vacuum leak, although they usually wont idle if it's a vacuum leak.
 

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Discussion Starter · #13 ·
Latheman and others
If you have retarded timing, would you get carb backfire when you rev engine while in park ?

I will be checking for fuel restrictions today as you sugested .
Thanks,
 

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Fuel

Olds 69 said:
Latheman and others
If you have retarded timing, would you get carb backfire when you rev engine while in park ?

I will be checking for fuel restrictions today as you sugested .
Thanks,
Doc here::pimp:

OLDS,

Your problem sounds like fuel starvation..

Check your Fuel filter (s) and try a pressure/Volume Check on the fuel pump (or just throw a new on..your call..)

Check the line for Bends, crimps dents and pinhole leaks...

If that all pans out ... Check your float levels.

Do a Compression Check...If the chain jumped It will be low all the way around...and hard to start (if at all)

Doc :pimp:
 

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Discussion Starter · #15 ·
Re: Fuel

docvette said:
Doc here::pimp:

OLDS,

Your problem sounds like fuel starvation..

Check your Fuel filter (s) and try a pressure/Volume Check on the fuel pump (or just throw a new on..your call..)

Check the line for Bends, crimps dents and pinhole leaks...

If that all pans out ... Check your float levels.

Do a Compression Check...If the chain jumped It will be low all the way around...and hard to start (if at all)

Doc :pimp:
Doc, I will change pump and filter today. It is just 30 bucks. What was puzzling to me that I could rev engine at park and it was perfect, timing, dwel and idle speed was right on. Then I took of and it started backfire but not all the time .
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If the fuel turns out not to be the problem, run the engine at night, in the dark. Look for a glowing blue aura around the coil, plug wires and cap. I am having the same problems with my F-150 and I noticed that the other night. Haven't yet got back out to start testing the ignition system. ---- long process. My cap is only 2 months old but looks like it was on there for years! lol I ran ok at an idle too but when I tried to drive it I also had backfireing and sudden jerks from where it seemed as though the engine was missing.
 

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Sounds alot like fuel starvation. You can rev it in park with no problem because the engine is under no load and needs virtually no fuel. Sounds like it is lean popping when you give it gas under load which is indicative of fuel starvation.

Chris
 

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TurboS10 said:
Sounds alot like fuel starvation. You can rev it in park with no problem because the engine is under no load and needs virtually no fuel. Sounds like it is lean popping when you give it gas under load which is indicative of fuel starvation.

Chris
Mine does pop under a load only in park also idle seems a bit choppy
 

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Try blocking off vac ret adv hose, test drive
iff no better check vac advance plate for movement and good wires,, iff no better you may have an condensor or coil problem,,
??? have you checked voltage to dizzy while running????

or coil
 
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