ZieglerSpeed
Well-Known Member
D150 run when I install headers and unplug the O2 sensor from ex manifold as in I don't use the O2
how does my early computer (stock 82 318 2 bbl)
- Thread starter ZieglerSpeed
- Start date
Jonnyuma
Well-Known Member
Could you rephrase the question?
ZieglerSpeed
Well-Known Member
I install headers on 82 D150. If I don't use the O2 sensor that was in the drivers ex mfld and just let the computer plug in hang, how will it run. No cat
Oldiron440
Well-Known Member
Not making any sense to me, please give it another try.
ZieglerSpeed
Well-Known Member
Ok, on stock 82 318 D150 the drivers ex mfld has an O2 sensor
ZieglerSpeed
Well-Known Member
When I install headers how will the truck run if I don't use an O2 sensor
Jonnyuma
Well-Known Member
My 85 RamCharger had a rudimentary computer and a carburetor... it was a mess.
I can't say for sure how yours will run, but a 1/2" drill bit, a bung, and new O2 sensor would probably relieve a headache or two.
Try it and see. My 85 ran fine with the computer disco'd... it just couldn't get past emissions.
I can't say for sure how yours will run, but a 1/2" drill bit, a bung, and new O2 sensor would probably relieve a headache or two.
Try it and see. My 85 ran fine with the computer disco'd... it just couldn't get past emissions.
Oldiron440
Well-Known Member
Adding a 02 bun in the collector is not a big deal, you will have to extend the wiring.
ZieglerSpeed
Well-Known Member
Yeah, I can add an O2 port. I'll get rid of cat and keep single exhaust using factory crossover behind headers
If there is an oxygen sensor, then it was used for the computer controlled carburetor. The oxygen sensor is the primary sensor for determining the air/fuel ratio – so with the sensor either unplugged or missing – it will run like crap.
Now if the carburetor was replaced with a non-computer controlled version, then the computer controlled carburetor would be a non-issue (if allowable in your state).
The computer would still control ignition timing, as normal, and computer would still be sending signals to carburetor (but the carburetor ain’t listening – think an old married couple, where wife is complaining you need to mow yard, vacuum, dust, laundry, change light bulbs, fix toilet (and so forth), all but he’s thinking about is how many football games can he watch this weekend).
BudW
Now if the carburetor was replaced with a non-computer controlled version, then the computer controlled carburetor would be a non-issue (if allowable in your state).
The computer would still control ignition timing, as normal, and computer would still be sending signals to carburetor (but the carburetor ain’t listening – think an old married couple, where wife is complaining you need to mow yard, vacuum, dust, laundry, change light bulbs, fix toilet (and so forth), all but he’s thinking about is how many football games can he watch this weekend).
BudW
ZieglerSpeed
Well-Known Member
At the Chrysler race seminars in 1978 Tom Hoover and Larry Shepard would say if you have a new car running in a closed room it purifies the air. My pick up is a 81 and it doesn't use a computer yet for pick up emissions. It's just the little "control unit" and no o2's so that experiment we'll put on hold. I would have liked to compare mileage. I have a 84 5th I'll try it on. -unplug o2 for couple hundred miles and compare mileage
ZieglerSpeed
Well-Known Member
I have had success building feed back thermoquads with no computer. The motor ran clean (lean plugs) mileage was fine and motors ran fast with them. I doubt the motors met emissions
Maybe the air was a wee bit thick back in ’78? All this time, I thought trees and grass purifies the air by absorbing carbon dioxide/monoxide and replacing it with oxygen.
Maybe the new cars in ’78 didn’t put out any carbon from tailpipe?
The pickup is at a disadvantage if you are using it for a fuel mileage comparison.
Anytime a computer controls the fuel (carburetor or fuel injection) and it is working correctly, it will always get better fuel mileage than one without a computer, by either a large or a small amount.
Now if your system is NOT working correctly to begin with, that is a different topic.
Unrelated (maybe), my ’86 Fifth Ave has a working and (almost) unmolested computer system on it. The original Holley 6280 (computer controlled) was replaced with a ’77 Carter BBD (non-computer controlled) carburetor about 10 years ago. The Computer works fine and is still controlling the carburetor (it thinks) and the ignition, but original carburetor is un-plugged and sitting on a shelf in my garage. The computer doesn’t know any different.
Car is getting about the same if not maybe a tad worse fuel mileage (that is, before the Holley 6280’s float sunk) after the changeover – but to be honest, I’ve not ever measured fuel mileage on that car – thinking what I don’t know can’t hurt me, I guess.
I have worked on hundreds (maybe multiple of hundreds) of carburetors – and I dislike Holley (any Holley) with a PASSION, which is reason I didn’t fix the old one.
BudW
Maybe the new cars in ’78 didn’t put out any carbon from tailpipe?
The pickup is at a disadvantage if you are using it for a fuel mileage comparison.
Anytime a computer controls the fuel (carburetor or fuel injection) and it is working correctly, it will always get better fuel mileage than one without a computer, by either a large or a small amount.
Now if your system is NOT working correctly to begin with, that is a different topic.
Unrelated (maybe), my ’86 Fifth Ave has a working and (almost) unmolested computer system on it. The original Holley 6280 (computer controlled) was replaced with a ’77 Carter BBD (non-computer controlled) carburetor about 10 years ago. The Computer works fine and is still controlling the carburetor (it thinks) and the ignition, but original carburetor is un-plugged and sitting on a shelf in my garage. The computer doesn’t know any different.
Car is getting about the same if not maybe a tad worse fuel mileage (that is, before the Holley 6280’s float sunk) after the changeover – but to be honest, I’ve not ever measured fuel mileage on that car – thinking what I don’t know can’t hurt me, I guess.
I have worked on hundreds (maybe multiple of hundreds) of carburetors – and I dislike Holley (any Holley) with a PASSION, which is reason I didn’t fix the old one.
BudW
Oldiron440
Well-Known Member
I have had good results with this also on a 440, once you get it rich enough it works fine.
ZieglerSpeed
Well-Known Member
Why different versions of the "control unit" ignitions were used? My Ram is an 84. It has a single ballast and a 4 pin control unit. The variations of this system seem to me like engineering had a tough time ironing out the details. I origion ally guessed my truck was an 82, sorry. 84, no computer and it is unmolested
All (V8 or /6) electronic ignition control units will all almost interchange fine.
Any 4-pin variant, which might be black, blue, orange, chrome or gold (only black or blue came installed on vehicles from factory - which are identical, except for paint color), will work in place of any 5-pin module.
A 5-pin version can fit in place of a 4-pin if a minor electrical rewire at the ballast is performed.
With that said, there are some control units that are better than the original ones (the Mopar Performance Orange or Chrome versions are one example) – for they allow higher RPM’s without a loss of accuracy.
Black (or blue) - good to about 4,500 RPM
Orange - good to about 6,000 RPM
Chrome - good to about 8,000 RPM
Gold - good to about 12,000 RPM!
The older 5-pin units have two power supply inputs. One for run/on and the other for start. The higher voltage during start gives more power to ignition coil for better starts.
What Chrysler discovered a few years afterwards, is instead of having higher voltage for startups (of say 10 volts), why not just use battery voltage at startups (at 12 volts) - which led to the 4-pin version. The starting performance did go up without any compromise of component longevity.
Chrysler runs less than 12 volts (about 8-9 volts, I think) for ignition coil to last longer during normal operation.
A higher voltage does equal higher output voltage to spark plugs, which makes for hotter sparks.
Some racers I know, who drive and race the car, will carry a couple of spare ignition coils with them, then bypass the ballast resistor, so ignition coil gets a full 12 volts when in race mode. The cars will run better – but lifespan of ignition coil is greatly reduced. Having a spare coil ensures he is still able to drive home after the “races”.
One friend of mine said he went through 3 Chrysler ignition coils over a weekend, after running 12 volts to the ignition module.
The 4-pin units, only have 1 power supply. What Chrysler did is when car is in “start”, it sends a 12-volt signal to output side of ballast resistor, then when switched to “on”, power goes back to input side of ballast resistor. Switching the “Start” battery feed wire to the 4-pin ballast, to the out side of “run” leg of ballast will allow you to use a 5-pin module (and car might start a wee bit easier).
I have a pair of these in my garage, waiting for install:
http://thertgarage.com/products.html
These might be overkill for those with stock vehicles - but is what I plan on using (the black version of above).
BudW
Any 4-pin variant, which might be black, blue, orange, chrome or gold (only black or blue came installed on vehicles from factory - which are identical, except for paint color), will work in place of any 5-pin module.
A 5-pin version can fit in place of a 4-pin if a minor electrical rewire at the ballast is performed.
With that said, there are some control units that are better than the original ones (the Mopar Performance Orange or Chrome versions are one example) – for they allow higher RPM’s without a loss of accuracy.
Black (or blue) - good to about 4,500 RPM
Orange - good to about 6,000 RPM
Chrome - good to about 8,000 RPM
Gold - good to about 12,000 RPM!
The older 5-pin units have two power supply inputs. One for run/on and the other for start. The higher voltage during start gives more power to ignition coil for better starts.
What Chrysler discovered a few years afterwards, is instead of having higher voltage for startups (of say 10 volts), why not just use battery voltage at startups (at 12 volts) - which led to the 4-pin version. The starting performance did go up without any compromise of component longevity.
Chrysler runs less than 12 volts (about 8-9 volts, I think) for ignition coil to last longer during normal operation.
A higher voltage does equal higher output voltage to spark plugs, which makes for hotter sparks.
Some racers I know, who drive and race the car, will carry a couple of spare ignition coils with them, then bypass the ballast resistor, so ignition coil gets a full 12 volts when in race mode. The cars will run better – but lifespan of ignition coil is greatly reduced. Having a spare coil ensures he is still able to drive home after the “races”.
One friend of mine said he went through 3 Chrysler ignition coils over a weekend, after running 12 volts to the ignition module.
The 4-pin units, only have 1 power supply. What Chrysler did is when car is in “start”, it sends a 12-volt signal to output side of ballast resistor, then when switched to “on”, power goes back to input side of ballast resistor. Switching the “Start” battery feed wire to the 4-pin ballast, to the out side of “run” leg of ballast will allow you to use a 5-pin module (and car might start a wee bit easier).
I have a pair of these in my garage, waiting for install:
http://thertgarage.com/products.html
These might be overkill for those with stock vehicles - but is what I plan on using (the black version of above).
BudW
ZieglerSpeed
Well-Known Member
Thanks Bud. I knew you would have some enlightening input. When I raced I used a chrome or orange box, set the alt up with 100 amp fields and diodes and run an adjustable cop car elect. v. reg cranked up to 15 1/2 volts. I'd run a super coil with the double ballast + a single ballast or things (control unit and ballast) would get HOT
ZieglerSpeed
Well-Known Member
I would wire it up following Chrys race manual and put many thousand miles on street/strip cars without a problem. My 360's saw 6000 r's, my 318's, 6500
Oldiron440
Well-Known Member
I haven't used either for some years but I still have both, I've heard from several forums and several threads that the new ones are hit and miss, and I'm not sure mopar sells them at all. The new ones are China copys of course, so you have to be careful about what your purchasing. The mopar parts were great, I switched to MSD chasing a miss that turned out to be a poor intake manifold.
ZieglerSpeed
Well-Known Member
The Chrys race seminars said the chrome box/gold box vs MSD was a toss up so I never went MSD
