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[slowbuick]

Hello all, I have a 80' century 3.8 2 barrel that dies under load. Basically, it has a ton of trouble starting, once started, it idles normally, but will die under normal acceleration. The car has a new carb, accelerator pump, distruputer, belts, alternator, battery, spark plugs & wires, valve covers, and fuel tank lines. Fuel pump is old but I took the fuel line off and cranked it and it shot a bunch of fuel out. Some vacuum lines are replaced, some are not, but are not horrible. Note, I drove the car for 3 years 0 issues and then one day it just died idling and that's when this started, carb has been cleaned since that and didn't help. Only thing im left to think is maybe a clogged cat however the exhaust does shoot out somewhat strong/normal if anything its worn. Would greatly appreciate any feedback.

 

[jcelk]

could be a clogged cat they will let enough exhaust out when idling but not at higher rpm while in park rev up the engine 2500 rpm is it ok or does it bog down ? or the timing chain could have jumped a tooth .

 

[Clone TIE Pilot]

Sticky needle valve.

 

[jcelk]

yea good idea you could unbolt the cat

 

[Clone TIE Pilot]

Is the needle valve part of the carburetor? If so I doubt its the cause as it was professionally cleaned, looked at, and tuned.

Depends on the quality of the parts used. Cheap parts degrade quickly when exposed to E10 gas.

The needle valve is what controls fuel flow into the carburetor. It is connected to the fuel float. The needle has a viton tip and low quality ones can become sticky and not allow enough fuel through at higher RPMs. A cheap neefle can degrade in days.

 

[jcelk]

don;t see why not it will be loud they used to sell cat bypass pipe that would install in the place of the cat or sometimes they hollowed them out just as a test

 

[jcelk]

just a thought have you looked down the throat of the carb while not running to see a good stream of gas from the accelerator pump? and plug off as many vacuum lines as possible brake booster evap system; egr ; heater control vac line; ;pcv valve to rule out a vacuum leak .to undo cat they are usually very rusted bolts needing to heat up the nuts with a torch or cut them off also i don;t know if they sell the bypass pipes anymore

 

[Rocknrod]

Is this something that I could replace myself relatively easy. I don't want to make you work but if you link one for me. Would greatly appreciate it.

You might want to watch this 3 part series and determine if you can do it yourself -

 

[SoFloG]

This is your second thread bud and we've all given you tons of sound suggestions. Not to be a dick but you keep saying you had a professional rebuild the carb and work on the engine... seems like you have a lot of faith in whoever did the work and the integrity of the parts used. While it may have run for a while after you had the work done doesn't mean that parts like the carb especially or the "work" performed were up to par to begin with. Not to mention, a couple tanks of crappy gas can wreak havoc and degrade the fuel system in a short time.

I mentioned the spark plugs, and you ruled them out by checking them for spark against the block, correct? Even a completely fouled plug will spark when grounded, but won't necessarily be up to the task of sparking enough to create combustion while installed in your engine and under load. You also may have a cracked plug, plug wire grounding out somewhere, etc etc etc.

I suggest you post some pictures and better yet video of what the car is doing. With all the knowledge on this forum we are limited to what you are conveying through messages regarding the symptoms and have no visuals to possibly see something that you don't.

I personally want to help you remedy the siuation and I'm sure others do as well which is apparent. Please post some pics of the engine compartment, spark plugs, fuel filter, battery terminals, etc. Lets solve this!

 

[jcelk]

to plug the vacuum lines you cap the nipple coming out of the carb .. a cracked plug will cause a misfire to cheak this ;while idling pull one plug wire off at a time rpm should drop if it doesn;t something is wrong with that plug use a plug puller or don;t ground yourself to the car we all got zapped a couple of ttimes