nater

84 berlinetta with 305. stock computer controlled distributor, bare bones qjet from a boat. no big mods that i know of besides carb swap, which was done by the previous owner. the car ran pretty good for about nine months with only a minor transmition issue. the last couple of weeks it went from getting about 20mpg mixed to an optimistic 12 just highway. and the coolant sensor seemed to not be working(i lost tc lockup after it got very hot one day while testing a electric fan setup). i swaped in a coolant sensor from a diferent motor. not the corect one but it helped a little for a couple of days. then one day it started jumping the timing around and burping flames out the carb. i was able to reset the timing enough to limp it back home. i pulled the trouble codes and it shows almost all of them including a number 11 which i can find a lot of info on. starting cold the car runs just fine now untill it gets hot then the timeing goes everywhere. if i pull the brown wire on the distributer the car goes back to idleing just fine, but then there is no advance. any time i restart it its fine until it warms up, even if i dont ajust it. i am 90% certain its not the timing belt. this all started happening back in june and right after it happened i left for drum corps tour and didnt see the car for 2 months. i have been trying to diagnos it since i got back with no luck. i know i should have a non computer distributor to match the non computer carb, but is that my only problem? could it be fried computer? just the bad coolant sensor?

86LG4Bird

iTrader: (1)

"..starting cold the car runs just fine now untill it gets hot then the timeing goes everywhere. if i pull the brown wire on the distributer the car goes back to idleing just fine, but then there is no advance. any time i restart it its fine until it warms up.."


Those same symptoms turned out to be a bad ECM in my case.

jmd

iTrader: (4)

You're right; If you're using a non-ECM Q-jet ("bare bones Q-jet from a boat"), with "stock computer controlled distributor," timing isn't going to be effectively controlled and you'll not achieve best fuel economy / drivability. The ECM uses the TPS signal to control timing. And primary fuel mixture.

Is it the only problem? Too many variables to answer that. You might:
- Try and score pictures, the Q-jet, maybe hoses and evaporative hoses & "stuff" off a V8 junkyard Chevy car with ECM Q-jet.
- Go for a non-ECM distributor. It will take you some time to set up advance for best timing.
Since I've pulled 25mpg with 305 and 350 engines with a CCC Q-jet, that's how I would tend to go, but it takes some time & knowledge.

nater

ya i figured the ecm was probably fried judging by how it pulls all of the codes. i was planning to try to get a non cc distributor just before it died. now that i have a little more time i dont realy know what cars to look for at a junk yard that would have a compatible distributor. i want to restore the car to a driving condition over this winter and have it ready for spring. i mainly wanted to check and see if there were any other major possibility causing my problem other than the ecm being toast or a bad timing belt/chain(which i am still sure its not).

i would try to find a cc qjet as i have all of the wiring and vacuum there(pluged up of course) but if the computer is fried then i dont want to spend money on both. i am pretty positive it isnt just the mismatched dist. and carb as it ran fine(not the best but ok) that way as a daily driver getting about 20 mpg from September 2014 to June 2015.

any suggestions on where to get a non cc distributor that will fit the car?
any suggestions on other things i should check and or do when putting the car back on the road?

John in RI

iTrader: (167)

You can get a new small block Distributor pretty cheap these days,..... I wouldn't spend a dime anywhere else until you get a vacuum advance distributor mounted under the hood.

http://www.ebay.com/itm/Chevy-SBC-350-BBC-454-65K-Coil-HEI-Electronic-Distributor-Red-Cap-/171429041762?hash=item27e9f79662&vxp=mtr
* There are OBVIOUSLY much better distributors out there, but this thing includes a new coil and cap,... for $50 delivered.

When you set the initial timing ( with Vac Distrib ) be sure the vacuum on the distrib is plugged ( as well as the carb port for it ) and be sure the car has fully reached operating temps before setting the final timing adjustment.

Don't believe anything that ECM says - If the ECM controlled carb is missing then you will get garbage feedback from your ECM.

nater

ok john thanks for the info and all the other help with the berlinetta stuff. i would still like to know for a second option what cars to look for in a junk yard to get the distributor from even if it would have to be completely rebuilt im ok with that. any ideas?

John in RI

iTrader: (167)

No Problem dude !!

Any factory Vac distributor you *might* find in a boneyard is going to be 30+ years old and I would avoid them at all costs. You could look under the hood of some of the 80's GM cars/trucks and might get lucky to find a car that someone installed a vac advanced distributor into,... but rebuilding it to ensure it's good will probably cost more then the price of a new part you can get delivered to your door.


I gotta' be honest here; @ $50 for a NEW distributor with coil and cap,... You just can't beat that !

nater

ok so i picked up a dist from amazon, its not the highest quality but it works and im pretty sure that was the whole problem. ive still got some tuning to do with it. i tried the basic setting from the tech article, minus springs. anybody got any other tips on how to tune the noncc distributor?

also are there any other mods that anybody can suggest while im working on it? the car will most likely be made back into my daily driver as soon as there is no more snow, as the truck i am driving now is a f*rd enough said there. i miss my camaro.

nater

ok update. i did put the car back on the road and it has been going good. at first i though i needed to mess with the advance curve a lot, but it turns out two of my plug wires that i though ran parallel were actually crossed just below my exhaust manifold and were misfiring bad. the car runs much better, but there are some problems still. mainly at idle once the car warms up in neutral my rpm is 1200 ish and when i go into drive it drops to 700 but cant hold that without me feathering the throttle also coming off cruise it seams to want to push against the breaks a lot, way more than i feel safe. it almost dies at idle in drive but if i have it in neutral and go to drive it feels like a neutral drop. if i give it any throttle at all though its fine in drive. could this be that my vacuum advance is hooked up to full manifold vacuum. as far as i can tell there is no timed port on my carb the place where it should be seems to not be drilled all the way through. i have been told to use ported by many people to prevent the neutral drop problem. if anybody is an advocate of full manifold vacuum for advance how do i not neutral drop all the time. right now the car is down for a bit while we do some exhaust work and i did the plugs while i was at it as well as set the float level a little higher. im hoping that helps a little but i expect the problem will still be there to some extent, i haven't fired it up yet as i just got the manifolds on before dark.