Alright guys the time has come that im planning on swapping my 3.1 cammed header swapped car to a carburetor set up and nixing the factory constrictive efi intake. Im not posting this to get convinced other wise by all the nay Sayers and carb haters out there. I just need some help from some of the people on here who might know a few more things than me. Now that that is out of the way. Iv already purchased a Holley 8007 carb and plan on buying the intake from edelbrock. That takes care of the simple mounting of it, then I need to put an inline regulator to regulate the pressure down to the 7psi recommended for the carb. I would like to leave my efi pump in the car in case I ever want to go back but If I cant regulate it down enough Ill just install and 4cyl fuel pump and regulate that down. That pretty much takes care of the fuel issue, then I need to figure out ignition. I found a old thread listing to use a distributor with vacuum module from an 84 blazer 2.8. I get that the vacuum line gets plummed to the intake and that will give me spark advance but this is where Im confused or rather ignorant. On the old blazer style distributor what wiring is there if any at all, I see it appears to have some kind of electrical module even on the vacuum distributor. I also dont know what coil to install. Can any one clear up the blanks here that i am confused about.
Ok so I get the pick up coil on the dist plugs into the icm, then that leaves + and ign coil/ tack lead. What coil should I be using for this application, and I assume + is just 12 volt switched ignition on.
yes, but that coil has 4 terminals on it in additon to the main coil wire terminal. Im trying to find a wiring diagram for that coil now but am not having much luck.
And if I understand this at all completly. The icm would have 4 pins. two of which connect it to the pick up coil then two others. One is 12volt switch hot and the other is out to the coil. It would run to the + wire on the coil, and from there the coil the yellow and black "-" and "ground" leads both go to ground where ever you want?
Use the stock S10 coil. The ICM will intermittently ground one side of the coil. The other side of the coil needs to be wired to switched +12.
The ICM to ignition coil wire also needs to be extended to the tach input.
The way GM did it is they have two terminals for each function. +12 goes to the coil. The other +12 terminal of the coil then extends the +12 to the +12 input of the ICM. These wires are normally Pink.
The C wire of the ICM runs to the coil. The other terminal of the coil runs to the tach. These wires are normally White.
That is why GM has four terminals instead of two.
[This message has been edited by phonedawgz (edited 11-27-2016).]
More power, better economy, cheaper, more torque, and better looking.
You say the EFI intake is restrictive. Ok, I'll buy that. How much are you going to spend on this carb setup? $800? When all is said and done? You could fabricate a pretty kick@ss manifold for $800. Heck you could do full ITB's for that much.
Who is going to do all of my welding to make mye "kick a@@" manifold for 800 bucks. I still also am stuck with an ancient ob0 computer that is in all truth un tunable. Also I would argue a carb is always sexier then an efi set up. The carb removes all the intake restrictions and allows for better tunability then the stock computer ever did.
Carburetor engines work well on the drag strip as they can be tuned to work at WOT very nicely but on the street its an entirely different story. If you are concerned about gasoline mileage , engine efficiency, longevity, consistency of engine operation over all climatic conditions EFI would be a better choice.. Back in the day carburetor engines were all worn out by 60,000 miles. Today with EFI, properly taken care of engines can last 200,000 miles. Here in my state, cars over 25 years old do not have to submit to a vehicle inspection. If you live in a state where inspection is mandatory you will not pass with a carburetor engine. Not trying to tell you what to do, just providing some food for thought. Good luck with the project
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I live in Texas and am well aware of emissions laws. Here emissions basically isn't even a thing unless your in a big city. Carb set ups also don't effect longevity of engines, proper maintainence does. I also believe I prefaced this post with useful information only not nay saying.
Why don't you just leave the ECM to handle the timing and leave the distributor alone?
Using a carb for fueling doesn't mean that you need to ditch the computer-controlled timing advance.
You have a point. I suppose one could just unplug the fuel injector harness and remove the factory intake assembly and install the carb. I hadn't really thought about that. Thanks for the blonde moment. My only concern there would be is what does the computer use to manage the advance? does it decide on how to advance timing based off of the Throttle position sensor, or the manifold pressure sensor? Vacuum advance may be the only option if that is the case.
Originally posted by Dennis LaGrua: Here in my state, cars over 25 years old do not have to submit to a vehicle inspection.
If you ignore that NJ PA and others Antiqued etc tags limit driving to shows, parades, and so on because these tags have no inspection.NJ is tougher than many because requires No Modifications to the car. You might get away w/ ignoring state law for years locally then drive in another city/county and get stopped and ticketed or worse.
Brief Description & Eligibility - Historic registration may be assigned to an antique vehicle which is at least twenty-five (25) years old. The vehicle must be owned as a collector’s item and used solely for exhibition or educational purposes. Please note that the vehicle cannot be altered from the manufacturer’s original design in any way and must be equipped for legal operation on New Jersey roadways. Historic registration must be renewed every three (3) years, but there will be no fee for the renewal.
The vehicle must be covered by the minimum automobile insurance coverage required by the State of New Jersey.
Quick Example because I'm not digging thru NJ DMV Laws/Rules for full text.
While NJ stopped Tailpipe Emission Testing (After May 1, 2016) many places still do. Missing emission equipment can still fail NJ inspection for old cars.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
You have a point. I suppose one could just unplug the fuel injector harness and remove the factory intake assembly and install the carb. I hadn't really thought about that. Thanks for the blonde moment. My only concern there would be is what does the computer use to manage the advance? does it decide on how to advance timing based off of the Throttle position sensor, or the manifold pressure sensor? Vacuum advance may be the only option if that is the case.
The Fiero ECM is a ""speed-density" engine computer. The two primary inputs to the main spark table are:
RPM
MAP
The ECM already knows the RPM by its connection to the distributor. As for the MAP sensor, make sure that it sees plenum vacuum (NOT ported vacuum).
Oxygen sensor: would probably eliminate it, since it would just make the ECM throw a code for an incorrect mixture. May be wise to try with/without.
So basically this setup is like a distributor with plenum vacuum advance, and mechanical advance... but these two advance mechanisms are built into the main spark table. You still adjust base timing by rotating the distributor as with a conventional distributor.
I've never tried/tested this idea, so I'm just throwing this out there. If it works, great! If not, you haven't really lost anything (except for time)...
define plenum vs port vacuum for the MAP sensor.... But I like where your going. I can always buy a vacuum advance distributor and do that, they do make a drop in hei vac advance 60*v6 distributor.
Oxygen sensor: would probably eliminate it, since it would just make the ECM throw a code for an incorrect mixture. May be wise to try with/without.
So basically this setup is like a distributor with plenum vacuum advance, and mechanical advance... but these two advance mechanisms are built into the main spark table. You still adjust base timing by rotating the distributor as with a conventional distributor.
I've never tried/tested this idea, so I'm just throwing this out there. If it works, great! If not, you haven't really lost anything (except for time)...
Is the transmission a manual or automatic?? More troubles if an auto...
You'll need all the sensors for the ECM to handle the TCC (torque convertor lockup) properly. I ran into that problem when I had the automatic with the carb/dist SD4 engine.
Frankly, given the advantages of injection, I'd have just sourced a less restrictive injection intake from a 3.4 and had it optimized for flow. It wouldn't be the bottleneck for power, the heads would.
Is the transmission a manual or automatic?? More troubles if an auto...
You'll need all the sensors for the ECM to handle the TCC (torque convertor lockup) properly. I ran into that problem when I had the automatic with the carb/dist SD4 engine.
Two of my old Lincolns, a 59 and 60, both completely stock had 430 ci V8s with 2bbl carbs. They both passed emissions tests here, even though theyre not required. No cats either...complete dual exhausts. They also got almost 25mpg highway.
Two of my old Lincolns, a 59 and 60, both completely stock had 430 ci V8s with 2bbl carbs. They both passed emissions tests here, even though they're not required. No cats either...complete dual exhausts. They also got almost 25mpg highway.
That is possible but states usually factor in the model year and engine when doing emissions testing. I would assume that your car met the standards of the day. In this thread we have a man who is dead set on using ancient obsolete technology. As far as the law goes, he is on his own. I fail to understand the motivation of anyone building a street engine using a fueling device created in the early 20th century. Its like getting rid of the starter to use a hand crank.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Originally posted by Dennis LaGrua: 1. That is possible but states usually factor in the model year and engine when doing emissions testing. I would assume that your car met the standards of the day. 2. In this thread we have a man who is dead set on using ancient obsolete technology. As far as the law goes, he is on his own. I fail to understand the motivation of anyone building a street engine using a fueling device created in the early 20th century. Its like getting rid of the starter to use a hand crank.
1. Nope. Most states never counted engine or most years when setting Emission Test Limits for cars and light trucks. You might see before X year no test, between X - Y years simple test, Y to current full testing. (MD does just that.) Most states has limits based on Gross Weight to separate big trucks. Worse Many reduce the limits over time to keep EPA happy. If your old and/or mod'ed car fails then Fix the problem, Junk/Sell the car, or try to get a waiver. Waiver in DE cost $873.00 for 1981 and newer vehicles for north counties and only last 2 years max then back to square 1.
2. anyone using a carb for street use is ___________. A bit crazy is nice... No carb can match entire engine loads etc. Ford tried Variable Venturi carburetor but is a nightmare when you try to find a problem. I like Ford but VV carbs are crap. Even 1 or 2 port TBI are better then a Carb for most uses. Unless you rewrite ECM/PCM code... they will barf trying only to set timing. Anything missing can cause Error Codes and ECM/PCM can trip limp home mode using default settings. Vac Advance Distributors are not simple to setup properly. If the weights, springs, or vac parts are just a little bit wrong for engine used then the timing will have problems. Mechanical Distributors for super/turbo engines are even more problems to setup because they have to deal w/ boost retard timing. A turbo can use vac advance to start a run then turbo spool up and switch to boost retard very fast.
If your state still require tailpipe test... You will likely have problems trying to pass w/ a new carb and mechanical HEI. More so when state have 2 speed test, worse w/ rollers. You might pass at idle and fail at ~2200RPM or other way around even with a good cat.
Here in Texas Fieros only have to pass a safety inspection. They don`t even care if your engine light is on. I have a 3800SC swap and the only reason they even ask to look under the hood is to check it out. Otherwise, they wouldn`t even look at it. As far as carbs go I don`t care if it`s efficient or not, I`m old school, as some of you guys are and I like the idea of old technology. If an old car won`t run it can only be a few things and they are usually pretty easy to find. Plus, I have changed a mechanical fuel pump on the side of the road. Try that with newer one unless you don`t mind dropping the tank on the side of the road.
[This message has been edited by TXGOOD (edited 12-01-2016).]
Well, now that you mention it. Nearly all newer BMW fuel pumps can be changed on the side of the road. My 2013 only requires a 10mm wrench (Or pliers) to do so, and is easier/cleaner than any SBC fuel pump to change.
If your car won't run, it's still the same things that can be the cause. Air, fuel, spark, or timing. It's even easier to determine what the problems are, as the ECU tells you. I hate to use a modern BMW computer as a comparison as the 2.8 ECU is about as antiquated as a carburetor, but the ECU logs and real-time displays all the information you could ever need for a problem diagnosis.
Even if you don't have emissions, trying to build a clean-burning engine should still be a priority. It's better for the environment, and there should be no question as to how important that is. Just remember how bad LA was in the 80s. It was hell, brown skies every day. Having a dirty engine does nothing for you. It does not free up thousands of horsepowers that our cat converters are stealing. Because my 200hp/l bike still has cats, as does my 180hp/l car.
I'm not going to convince you, it's like arguing the color of grass with a blind man, but there's a reason modern cars use fuel injection. It's simply better, at everything.
I'm not going to convince you, it's like arguing the color of grass with a blind man, but there's a reason modern cars use fuel injection. It's simply better, at everything.
..........and I might add, so easy to make tuning changes with a laptop with scanning and editing software. You can adjust timing, fueling, shift points, shift firmness, tire size/speedometer adjustments and alter the power curve without opening the hood. You cannot possibly obtain optimum fueling and timing over the entire RPM range under all conditions with an ancient outdated dumb device like a carburetor.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I agree that the newer technology is always adjusting fuel and spark for optimum performance. I don`t really care to adjust things with a computer and further more a computer won`t tell you everything. That`s whats wrong with some of the newer mechanics. They can read what the computer says but when the computer throws out a code it can be a number of things and those without years of experience can`t always make an educated guess as to what that can be. And I realize that you still need fuel and spark to run but the list of things that can be wrong if you have nothing from either of those can be a lot longer with all of the technology compared to old school.
I agree that the newer technology is always adjusting fuel and spark for optimum performance. I don`t really care to adjust things with a computer and further more a computer won`t tell you everything. That`s whats wrong with some of the newer mechanics. They can read what the computer says but when the computer throws out a code it can be a number of things and those without years of experience can`t always make an educated guess as to what that can be. And I realize that you still need fuel and spark to run but the list of things that can be wrong if you have nothing from either of those can be a lot longer with all of the technology compared to old school.
Translation - thinking about fuel injection makes my brain hurt!
If you are constantly changing things in the engine and have no computer skills I can see your point, but if it is to just run one engine set up that won't change, all you need to do is enlist the aid of a tuner once and it is done.
To me, the appeal of the Fiero is that it is outdated. It provides a refreshing contrast to modern life.
If I wanted high-tech modern two-seater, I would have bought an FR-S.
Those of you who think electronic fuel injection is a must because it's "better", what are you doing driving a Fiero? Even if the engine is updated, the rest of the car is still a relic from the days before 3D CAD...
[This message has been edited by pmbrunelle (edited 12-10-2016).]
Those of you who think electronic fuel injection is a must because it's "better", what are you doing driving a Fiero? Even if the engine is updated, the rest of the car is still a relic from the days before 3D CAD...
Uh - because the Fiero has technology contemporary to the 1980s, including fuel injection? And there is zero dispute that FI IS superior to a carb - it not only gives more accurate mixture calibration, it double checks that calibration multiple times each second, the equivalent of taking your car with carb, putting an exhaust gas analyzer on it,checking output and adjusting it to spec.
Anyone that can't see the superiority of FI is being intentionally obtuse, and anyone that fits a carb to an originally injected car is, in many jurisdictions, a criminal.
Originally posted by BillS: Anyone that can't see the superiority of FI is being intentionally obtuse, and anyone that fits a carb to an originally injected car is, in many jurisdictions, a criminal.
