Hi all
about 5 years ago, i parked my 86.
due to constant nagging, i agreed to get it running again.
i had put a 383 in it 5 years ago, and put 1989 corvette alum heads on the engine along with a 52 mm throttle body, adjustable fuel press reg, a ram jet cam from chevy, and it pinged pretty badly.
so now, i put the original 350 heads on the 383, the original plenum and throttle body with the original parts , (TPS, IAC,
cold start sensor, computer temp sensor, etc).
the car has true dual exhaust with bullet cats, 91 vert mufflers, ported original exhaust manifolds, and a 1987 corvette factory chip in the computer.
i unplugged the egr solenoid, moved the MAT sensor to the front of the car.
k&N air filter, high volume fuel pump, 1.6 rockers.
i ran 3 tanks of gas through it with a little injector cleaner.
it’s like the o2 sensor isn’t reporting to the computer
black exhaust.
why?

 

So today, because i have the time, i hooked up my scanner, and the scanner message was that it couldn’t communicate with the vehicle.
played with it a little, changed scanner batteries, etc. I wasnt getting anywhere
So, i put the 52 mm throttle body back on the car.
i know the TPS was calibrated correctly, and the IAC worked good the last time i drove it.
it ran so much better.
drove it around for an hour, and at the end of the hour it was starting to “relearn” the new throttle body.
It runs fairly well in open loop, but now closed loop, not so well.
i tried changing o2 sensor, but cannot get enough leverage to break it loose from the top.
no room in the garage to jack it up and get to it, and it’s raining. so will have to wait.
put 1.5 rockers on it, and seems smoother and tires spin (i know it’s raining) with not much gas.

 

i could help with a stock setup but it sounds like u have a very different system. did u install yourself or did u have a builder?

 

Is the "chip" tuned to your modifications?

 

It’s a stock setup,
when i put everything together, i nickle and dimed it as i could afford.
i lost my job, and that’s where the fun ended.
so it sat for five years while we financially recovered.
the engine was a new short block, i bought an 89 vette engine at a wrecking yard, and got all the pieces.
then they offered me a couple corvette
engines, a 85 and an 87 for $1000.
then i had pieces and parts to interchange.
the trans is a 91 firebird trans am with the 86 tailshaft housing.

 

Dont know if anybody remembers Superchips.
I had one in there for a while.
then put in an 87 stock chip because i was using alum heads, and the ign. timing is different from iron heads.
fuel, temp, fans, etc. as u all know.
o2 tomorrow if i can find some dryish concrete

 

Ya know,
the egr is not hooked up, so the temp sender for it should be tripping a code and turning on the ses light.
no codes.
in the garage last night i noticed the security light wasn’t blinking.
ilocked it, then through an open window, un locked it and opened the door and no alarm.
somebody doesn’t like “like” so it’s as if there is an electrical anomaly that is affecting various systems.
going to have to check everything, and when i can get it out of the garage and open the door without rain, i will have to start with fuses

 

Because of corona virus, staying home.
increased fuel pressure to 48 lbs.
cranks excessively before it starts, so there may be an issue with the fuel pump check valve or leaking diaphragm in the fpr.
swapped out the fuel pump relay with another one, and it started initially like usual, but subsequent starts were quick.
as a side note, dash fuel monitor displays 21 mpg at 49 mph when converter locks up with a steady speed.
at 70, it is displaying 34 mpg, level road and steady speed.
don’t know how accurate that is.
rear tire size is 275/40/18.
standard size for a C5.
Going to put 1.5 rockers on just the intakes, and leave the 1.6’s on the exhaust.
since i am socially distancing, i have more time to play.
it really needs lower gears, but now that i pissed off the neighbors, not going to antagonize them by having large parts sitting around or garage door open for perusal with my truck sitting out.
thanks for everybody’s input.
my scanner is for OBD ll, and doesn’t work on this.
no check engine lights or visual abnormalities. Temp is right around 205, without air, Fan is on at 230, with air, fan is on at 210.
it has aux fan in front of radiator, and i tied the aux fan relay to the main fan relay so it comes on at the same time, and it cools off faster.
to compensate for the electrical load, it has an alternator from a 94 corvette.
i think it is a 140 amp instead of the 105 amp it came with.
works great. Used a 1985 upper bracket so it doesn’t rub on the hood.
and yes right muffler plugged up with cat material, and no precats.
both mufflers i removed had something inside that sounded like rocks when shaken.

no codes