83 camero v6 2.8 engine dying

[berniescout]

1983 v6 2.8L 2bbl automatic berlinetta brother bought new no problems until it sat for 2-3 years. he gave it to me in 1995 engine would occasionally stumble and die would (will) restart immediately. I have replaced all ignition parts except distributor including :ign module in dist, cap, rotor, wires, plugs, coil, have also put on rebuilt carb, replaced temp sensor and wiring, o2 sensor, all vac hoses, fuel pump,Map sensor and computer. I have had engine codes of o2 sensor, throttle position sensor, map sensor. currently no codes and problem still exists. when the engine stumbles and dies it is usually around 1500 rpm when i pump the gas it catches and away it goes. it is better since the rebuilt carb. (rochester verijert II) professionally done . at this point i think it is fuel related. because when i pump accelerator it goes. all i see is fuel pump is the reason i replaced it before because it was leaking oil (I had it done) by mechanic. also the tranny was rebuilt a few years ago. it shifts smooth the car has 90K all synthetic oil any suggestions ?????

[89IROC&RS]

when was the last time you changed your fuel filter?

[berniescout]

new fuel filter with new carb last week. i really dont think it is ignition related as when i pump gas pedal it responds or dies. how about if i disconnect the cruse control

[89IROC&RS]

i wouldnt start disconnecting stuff unless you have reason to think its causing the problem. I would say that there is something wrong with the carb, but im a Fuel Injection kinda guy so im just on the fly here.

what it sounds like is that your fuel bowls are going dry at idle, and then when you pump the gas your secondarys allow more fuel in richening the mixture and keeping the engine running. All i can do is describe a senario, keep in mind that my terminology could be wrong and everything, but that sounds possible to me based on what i know.

The rebuilt carb, who did the rebuild? what did it come off of? was it the original carb? was anything changed? Im lookin through all the stuff youve had done, and the carb is the only thing i can think of that could be the problem point. Im thinkin something internal is incorrect. but we need some carb guys on here to figure that out.

[berniescout]

car will idle fine for hours, carb was rebuilt by champion carb rebuilders a major supplier of rebuilds. the engine purrs untilll this happens. i can drive for 10-15 miles and then bingo. it may happen once or several times in a row then be fine again. i feel it is fuel. the only parts not replaced are a idle speed dash pot. had to transfer it from old carb. this just slows the ilde speed drop when you remove your foot from the gas pedal, and the carb to manifold gasket. the orignal was a heated model about 5/16 inch thick. it was in bad shape had "a melted glass look to it" i replaced it with a non heated gasket. the car does not have to pass emissions the only other thing i can think of is the distributor. but i would think it would be happening all of the time with rough idle etc if it were the distributor help out there?????

[89IROC&RS]

thats a tough one... did you ever do anything regarding the error codes? new O2, new TPS, or new MAF???

[berniescout]

Originally Posted by 89IROC&RS

thats a tough one... did you ever do anything regarding the error codes? new O2, new TPS, or new MAF???

yep, all codes cleared new o2 sensor, new tps w rebuilt carb., new map over the summer map code had two vac hoses crossed a coworker suggested the dist advance could be hanging bad spring or hanging weight. any thoughts out there !!!! getting desperate as son wants the car. just turned 16. and i want my 97 blazer back. he has it now. I'm driving daughters geo tracker, she is away at college and she will want it back over xmas break. got to have wheels!!!!

[DaMoNe6969]

possible you got a weak/defective fuel pump?

[berniescout]

thought I'd bring this up again . I have talked to two mechanics. One thinks fuel other thinks ignition! does anyone have any 83 v--6 experience? all vac lines good, etc. I lean toward fuel stravation but dont know. runs great at idle and only stalls intermittantly around 30-40 mph once every 20 or so miles. usally the stall or bog occurs in a series of them over a mile or so then all ok for many miles. no codes now after all of the repairs I have done. all that is left is distributor, egr, fuel line blow out or tank sock if ther is one. and emissions air circuits. help thanks berniescout (still wish I had by ihc scout 800 or scoutII --binder)

[berniescout]

thought i'd repost. spring is near (I hope too much snow this year and I love snow) need to get this baby running. anybody have any thougts??? I have a rebuilt distributoer ready to go. has anybody done this is it tuff. anything special i need to know on the 2.8L. any thoughts on the egr possible causing the problem???

[dolluper]

AS you were saying it stumbles at 1500 rpm well thats when about the EGR kicks in check your vac lines and maybe get a new aspesto's gasket and clean it out with a soft face [hate to say it] hammer and knock the carbon build up out of it make sure it at least moves[the vavle underneath ] at 1200 -1600 RPM If the valve moves and you have the same problem I would suspect the fuel pump But you also say you replaced the module did you apply dielectic grease underneath the mod before you installed if not the heat build up could cook it again or give you problems when hotter running conditions
edit: you should have a solinod valve for the EGR on the right side top of valve cover when standing looking at engine front cover[left valve cover] check it for shorts bare wires or not working I didn't think an 83 had one

[berniescout]

Originally Posted by dolluper

AS you were saying it stumbles at 1500 rpm well thats when about the EGR kicks in check your vac lines and maybe get a new aspesto's gasket and clean it out with a soft face [hate to say it] hammer and knock the carbon build up out of it make sure it at least moves[the vavle underneath ] at 1200 -1600 RPM If the valve moves and you have the same problem I would suspect the fuel pump But you also say you replaced the module did you apply dielectic grease underneath the mod before you installed if not the heat build up could cook it again or give you problems when hotter running conditions

dielectric grease-yes. all vac lines ok egr sounds interesting fuel pump is new the stumble stall usually happens when car is at steady speed never happens during acceleration. never at idle always between 1500 and 2000 rpm good thing i have plenty of hair to pull out

[dolluper]

I edited my post above read it

[berniescout]

i did replace a vac control which i think is for the egr valve. it was brand new gm part . no change i may take it for a spin this week end and pay close attention to speed and tach if it happens. thanks.

[dolluper]

Only one other thing I can think of [at the moment] is your dist shaft or gear is worn [shaft worn cause ground out sometimes on pick-up coil timer]gear could cause the lagg