hello all, ive been trying to post for months but FB login wouldnt let me so i "officially" registered

i have a 1983 Delta-88 RB 307 with some issues i cant figure out

SYMPTOMS (very day to day)
bad/rough idle sometimes sounding like only one bank is working
above normal high idle and not able to kick down
acceleration from almost non existent to decent but nothing over half throttle
throttle over half results in bogging/stuttering/misfiring
today it took about a mile to reach 30mph
stutters nearing shift point must lift off in order for it to shift
sometimes dies on idle or keeps running once shut off

weather seems to effect the running but in no consistent manner

problems started over the winter during the time a bad alt fried a battery then itself

trying to figure out the issue i have replaced the battery, alternator, coil, plugs, wires, ICM, fuel filter, sprayed out the carb with C&C cleaner and plugged off the heat riser vacuum hose since the riser is, well... not

many many thanks to any help anybody can offer!

 

I would recommend checking all the vacuum lines, it seems to be one thing you didn't mention...

 

It could be the catalytic converter is clogged.

 

for grins, take out the idle mix screws, shoot in a crapload of carb cleaner, chase with a little air and try again.

and, do you have fuel pressure?

 

How many miles are on the engine? Do or can you smell the exhaust when running? Did the tune up parts make it run any better?

 

i only didnt mention because in my frustration i forgot, it did have a vacuum leak for years (well before i got it) that i had found while replacing around 30 feet of vacuum lines, so theyre all good

 

unfortunately if only it were that simple but alas, there is no longer a cat on the car, when i got it the OE cat had been replaced and the AIR line just hanging there, i had to replace from the cat back so i just removed the cat at that time

 

as far as i can tell the carb has never been removed from the car and the casting plugs are still covering the the idle mix screws, fwiw this is one of the computer controlled carbs :/

 

its up to 87k miles i believe, you can only smell the exhaust if itd revd, smelling it wouldnt be an alarm for me as when whoever had issues with the heat riser apparently beat it out with a hammer knocked out the butterfly and pounded it back into place so it has an exhaust leak in that location.
tuning it up made no difference at all. my toss up is the carb needs a rebuild or a bad censor. at my count theres 5 sensors or the EGR that could potentially be causing a sporadic air/fuel mix

 

Thats ok, often the very act of changing the carb mounted fuel filter will send something that can stick by those screws (had it happen a few times in my day)

And the E4ME carb uses the mixture control solenoids for idle, once you get past say 1/4 throttle and vacuum drops (rendering any APT circuit inoperative) it behaves like a qjet.

at first glance, not being able to see, hear, smell or taste it from here, you are describing a fuel starvation problem. got an old fashioned low pressure gauge handy? Id like to see 3-7psi. more towards 7 than 3....

if its fubar, guy online has rebuilt E4's with a lifetime warranty for $218 if you send the core back in

 

Unfortunately I do not have such gauge, often enough it smells as if there's to much fuel, stinks of gas and the rich exhaust but that could because of the lack of a cat.. I do have a 2nd carb I got on eBay when I started having problems but it used/non remaned so the quality of the internals are unknown and what you get in rebuild kits just aren't what they used to be.

 

Give the EGR a whack with a hammer a few times while its running and see if it runs better afterwards .

 

If I can get it to idle without dying I'll give it a try!

 

If the EGR is the problem it will idle ok after you hit it a few times. Don't be afraid to whack it good. Don't pile drive it just a few good whacks should do it.

Eric

 

You should be able to move the EGR diaphragm with your fingers. Opening it at idle will make it stall. If it's stuck open, that will hurt drivability.

 

I had an '86 307 that had odd drivability issues that turned out to be sticking main metering rods. I rebuilt the carb (@ about 120k mi) and it ran great.

 

im currently uploading a couple vids/audio to youtube to post so you all can hear the bad idle and acceleration

 

do you know if choke is opening properly? also a bad purge valve can send a lot of raw fuel into the carb.purge valve connects to front top of carb,3/8 hose.there shouldn't be any fuel in that hose.

 

choke has been on my list of could bes since the start of this and i still have no idea if it is or not, its surprisingly hard to look into the carb no less while its running. i havent checked thr purge

 

 

I would double check the firing order. Those videos (to me) sound like mismatched wires.

 

unfortunately this problem started out of nowhere without the wires being messed up.. if only it were really that easy!

 

From my experience, i could tell if there was something up with the choke or its pulloff valves by manually operating the choke with the air cleaner off. Moving just a hair can make a difference. The pulloffs are difficult to find unless you know what they're called and will run you upwards of $30 from an auto parts store such as autozone, however, you can order it off rockauto.com for just a few bucks. Mine being bad caused absolutely terrible morning starts, i almost didnt even want to start it it sounded so bad. My 307 also had bad sputtering acceleration when one of the spark plug wires developed a hairline split which caused it to arc against any touching metal only detectable at night or if you touch it while the car is running xD

 

ive monkied with the butterflys and the choke a bit and they didnt realy seem to have any change in the running, i have rebuilt carbs before so i know my way around a qjet but its been awhile so im not sure what a pulloff valve is off hand. for a little while just removing the air cleaner lid would cause the engine to stall out, but now that doesnt happen... my guess still sorta is that the barometric pressure sensor is bad but then im into the hundreds of dollars can of worms replacing ever censor i can find!

 

Ive got an olds 307 thats fairly complete, just missing the vac lines and such. Its in a custom cruiser i used to drive until it ran its last mile. The engine is in great shape, i believe 80k miles or something around there. Nothing is new by any means but the car ran great and idled great all the time once i completed its tune up. If i have anything you may need, let me know for sure. Id love to be able to help.

And there should be a primary and secondary choke pulloff on your carb, both are connected to the choke and butterfly by a metal arm that controls them. You can tell its bad by taking off the attached vac line, compressing it manually, and covering the whole with your finger. If it holds pressure and doesnt extend, its good. If it extends as if your finger isnt covering the whole, time for a new one!

 

These are the choke pulloffs; red is the secondary, blue is the primary.

 

thank you very much for the offer! oh the vacuum bulbs lol i probably knew they were called pulloffs but its been at least 12 years since ive owned a carburated vehicle so understandably ive forgotten a thing or 2, i never even gave it the thought to check them

 

I had no idea what they were called either until i started looking for them and auto parts stores gave me the run around until i could have them search that exact term, otherwise the answer is, "sorry sir we dont have that in stock".

These olds wagons are my first carborated cars and i dont think i could have picked a more difficult candidate to work with than the 307, vac lines, vac lines and more vac lines lol

 

I've said this frequently, but it needs to be repeated. The CCC system (Computer Command Control) on the 1980s 307 motors has about a million possible failure modes that can cause rough idle and poor running. You MUST ensure that every single vacuum line is in good shape and properly connected. You MUST verify that the auxiliary systems like the air pump and diverter valve are functioning properly. Most importantly, you MUST follow the carb adjustment procedure in the Chassis Service Manual EXACTLY. If you fail to do this, you will be constantly chasing your tail looking for driveability issues. "Adjusting" random items in an attempt to band aid a problem will not fix it.

This is a very complex system with a pretty limited computer. Many of the functions are controlled with vacuum and temp sensors and switches that go bad or have leaks. The ECU will not pick these problems up as error codes; you need to perform good, old-fashioned troubleshooting.

 

well i just got to check and the primary pulloff was bad, fortunately the one on my spare carb was good.. didnt help the bad running but im thinking that was the the problem with my high idle not kicking down

 

hasnt been so much adjusting as replacing things hoping thatll fix it. the problems really did start out of the blue one day so ive been seening it as something that went bad

 

Well im glad we figured something out, next would be to verify that all your vac lines are hooked to the proper locations. Your little sticker on the inside of your hood should help with that

 

yeah, about that.... so the original owner what for whatever reason rattle canned the entire engine compartment, hoses, wires, engine, rad shroud... EVERYTHING!!!

 

Oh my...... How.... Creative....... Do you need a few pics for reference? Ive got the 307 in my custom cruiser and it has not, in fact, been defaced. Perhaps that could shed some light on your problems?

 

i think idiotic is the word you were looking for lol, im fairly sure my vacs are correct but as of today ad backfiring to my issues.. its strange how this keeps evolving

 

Mine idles slow until its been warmed up, sometimes it starts in fast idle and will speed up even more once its warmed up and wont stop until i press the gas then still idling slow until i drive it for a second. Other times it skips all that and just idles slow. Its definitely got a personality. Until its warm it lags when i go to take off for a split second. Im sort of afraid someone's going to tell me thats a very bad thing

 

THats the same way mine used to act, until the issues started, the backfiring today was while trying to accelerate, I think it was flooding backfire for trying to get up to speed, won't idle at all now even giving it some gas it tries to die. Still in the back of my head I'm wondering if this is an electrical problem. It all started with that bad alternator and now the gas gauge keeps going all wonky around a quarter tank.

 

No truer words have been spoken. The VECI (vehicle emission control info) label is required reading before any repairs or mods can go. If you have not removed equipment (putting you at odds with EPA regs) rendering the label info physically moot, the hose routing is critical for THAT motor to run as designed (whether or not you enjoy the design is another issue ;-) )

And beware, your neighbors label may not line up with YOUR label. There is a nonsensical alpha numeric number after or under the engine family designation and that gives great insight to the particular calibration and cert of that motor - there absolutely are multiple calibrations under any one engine family (49 state, cali, canada, export, high alt, HD etc)

Where is this magical sticker of info? radiator valence, air cleaner, under the hood are 3 acceptable locations to look for it (albeit the hood is more of a ford trick than GM)

and when re'wiring' the vacuum hoses, pay attention to keep included any delays, choppers or check valves, all of which can be had for new from Help! at advance. You can even get a new reservoir, albeit too small from advance...

 

Perhaps a bad fuel pump? I just had to replace mine

 

I doubt that has to due with the backfiring, but maybe with the idling.