quote Originally posted by GTFiero1: hey Oreif, what did you run in your 3.4 carb motor? I must have missed that thread

3.4L pushrod engine
Edelbrock custom ground cam (similar to the Crane 272 which was used in the EFI motor)
Ported, polished, and shaved heads (Raised compression to 9.4:1)
Comp Cams roller tipper rockers and heavy duty pushrods
Edelbrock 4-bbl intake
S-10 distributor recurved timing
Crane Fireball ignition system
Holley 390 cfm 4-bbl carb

Engine ran a 223 hp on an engine dyno.
Car ran 197 rwhp on a dyno after tuning (changed jets and secondary spring)
Ran 14.2 in the 1/4 mile with an auto trans

[This message has been edited by Oreif (edited 07-28-2006).]

quote Originally posted by rogergarrison: The biggest thing against FI is when it screws up your really screwed, usually means a tow somewhere to get it running with a carb, any trouble and it can usually get you back home.

You got that right ..I remember traveling out of state and my mech fuel pump went out ..I was out in the middle of nowhere in the middle of the night but due to my genius I was able to rig up a gravity feed to the carb to get me to the next town and wait till the morning to buy a new pump

quote Originally posted by Dennis LaGrua: A carburetor is old technology and illegal to use on vehicles later than about 1985

Turbochargers and fuel injection has been around since the 1940's. They are also "Old technology".
Oldsmobile had the first mass-produced production turbocharged engine back in the early 60's.
Auburn used them on a few vehicles back in the late 40's and early 50's.

As for carbs being illegal to use on vehicles later than 1985, My car is a 1986 and it is legal to drive on the street.
I have license plates, local vehicle sticker, auto insurance and an EPA compliance form.
I know someone who has a 1991 Trans Am who also happens to be running a carb'd V-8 that is also legal to drive on the street.
How is it illegal??? Could you show a link to this law that says it's illegal?? I've looked on Holley, Edelbrocks, Demon's, Barry Gratnt's, and Weber's websites and can find no disclaimers or notices that their carb's cannot be used on a 1986 or newer vehicle. I have searched thru the EPA and Illinois EPA websites and still have not found anything saying it is "Illegal to use a carb on a vehicle newer than 1985 (or any year newer than 1985.)".

(Please stop posting incorrect information.)

[This message has been edited by Oreif (edited 07-28-2006).]

well, looks like it wont go away....
you can have a carb'd motor with DIS
dont mix up FI with computer control.
there is mechanical FI (but...its a nightmare)
and, there are cars with carb's & ECM's
carb motors dont spin bearings? they dont have waterpumps fail? the alternator last forever? coolant hoses industrucatble?
these are real failures. sensors wont shut the car down. yes, a ECM failure leaves you stranded. even with a carb.
yes, the last generation of cars with carbs had ECM's (late 70's early 80's). that's probably why they sucked so bad, eh?!
I had a '82 Chevy Chevette with a carb and it had a ECM & a 'service engine soon' light - and it would not start due to computer problems.
it needed a special solenoid replaced IN THE CARB
it also had a problem with the electric choke. it would stick shut.
I would stick a screwdriver (that magic tool o' 'de carb) down its throat to keep the choke open - best of both worlds, eh?
damn POS

FI is just a fuel delivery system. it is not igntion. seems ALL electronic failures are blamed on FI - just not true.

believe me when I say I LOVE the simplicity of a classic VW air cooled beetle motor. now theres some endless & timeless reliablity.

quote Originally posted by Pyrthian: sensors wont shut the car down.

This is funny. Everyone seems to think a bad sensor won't shut down an engine.
Yes, you can disconnect numerous sensors and the engine will still run. But have a MAP sensor or O2 sensor short out and the engine will stop running. Seen it happen a a few cars. Disconnecting then opens the circuit, But if certain sensor short out, It will load down the ECM which will kill the engine.

Yes each system does have things that can go wrong. But some people seem to think that one system is better than the other. My point is they each have their pro's and con's. I have not said that either is better I said that they are equal. Both systems have been around for years and both systems have had major improvements over the years. The EFI systems from the 80's is nowhere near as good as the new EFI systems. In the same respect, Carbs of the 60's and 70's are nowhere as good as a newer carb.

The only time I said a carb was better was when I built my 3.4L. The ONLY I said it was because at that time there was no readily available intake that could provide enough air for a built up 3.4L. Once the Trueleo intake was available I proved that with nearly identical long blocks, The engines produced nearly identical power regardless of the fuel delivery system.

[This message has been edited by Oreif (edited 07-28-2006).]

quote Originally posted by Oreif: This is funny. Everyone seems to think a bad sensor won't shut down an engine. Yes, you can disconnect numerous sensors and the engine will still run. But have a MAP sensor or O2 sensor short out and the engine will stop running. Seen it happen a a few cars. Disconnecting then opens the circuit, But if certain sensor short out, It will load down the ECM which will kill the engine.

I can short out any sensor you want, and it will set an appropriate code, assume a "normal value" for that sensor, and continue running in fail safe mode.

quote Originally posted by ryan.hess: I can short out any sensor you want, and it will set an appropriate code, assume a "normal value" for that sensor, and continue running in fail safe mode.

That is not true for all systems. My 1995 Intrepid with a 3.5L V-6 had the left bank O2 sensor (they have two O2 senors) short out and the engine stopped running and would not start. It was towed to the dealership and replaced.
If I had known the sensor shorting would load the ECM down, I could have just disconnected it and the car would have started and ran. But I did not have the tools in the car at that time to check the codes to diagnose the fault.
(The Intrepid was the worst car I ever owned. The car left me stranded numerous times.)

Sister had a 2001 GMC Envoy that the MAP/MAF senor shorted out, Causing the engine to flood out and die.

Yes, most of the time the computers will go into "Limp Mode" and use a default setting for the bad sensor(s). But it is not a 100% true for all cases.

[This message has been edited by Oreif (edited 07-28-2006).]

Limp mode is for a processor or PROM failure. It doesn't even look at the sensors, it just tries to run the engine with hardware.

Fail safe mode is for a sensor failure, where a value is given to it to keep the engine running.

I can only comment on OBDI GM computers. OBDII GM computers are more sophisticated yet, and have better algorithms to detect bad sensors, but are not foolproof.

The great part about sensor failures, is the computer will tell you what's wrong. Had you or your sister read the codes, you might have been able to unplug the offending sensor, and driven home. You can fix a carb system with a screwdriver, wrench, timing light, and vacuum gauge; but you can fix an EFI system with a paperclip. (scantool for OBDII systems)

you dont need a timing light, wrench, or vacum gauge for a carb. You only need a screwdriver or similar tool. I can prob find at least 3 or 4 of those in each of my car. I dont have a paper clip I know of even in my office space.........

quote Originally posted by ryan.hess: Limp mode is for a processor or PROM failure. It doesn't even look at the sensors, it just tries to run the engine with hardware. Fail safe mode is for a sensor failure, where a value is given to it to keep the engine running. I can only comment on OBDI GM computers. OBDII GM computers are more sophisticated yet, and have better algorithms to detect bad sensors, but are not foolproof. The great part about sensor failures, is the computer will tell you what's wrong. Had you or your sister read the codes, you might have been able to unplug the offending sensor, and driven home. You can fix a carb system with a screwdriver, wrench, timing light, and vacuum gauge; but you can fix an EFI system with a paperclip. (scantool for OBDII systems)

Not all ECM's use a paperclip to get into diagnostic mode or read codes. Ford requires you to unplug a connector, Mopar has 2-3 different ways as well.
Fail Safe and Limp mode are the same thing. Just different terminology by different manufacturers.

With all the cars I have owned, I have never been stranded for a fuel delivery problem with a carb'd engine. It does not mean carbs are better, Just that there are more tools required to diagnose EFI problems which make it harder to locate problems on the side of the road.

[This message has been edited by Oreif (edited 07-28-2006).]

I would think the likelyhood of a sensor stopping your motor from running are about as good as a stuck float in a carb doing the same thing.

This argument is stupid. For maximum power and efficiency you can not beat FI. Carbs do have a place in this world, but the only race cars to use carbs usually do because of the rules, not because they rather have a carb.

Carbs- Metered fuel leak.

I do not dislike carbs. I think thery are pretty damn cool on an old school big block. They are just inferior to modern day fuel injection. If a carb makes more power on any particular application than FI, its usually due to intake manifold design, as on the fiero.

quote Originally posted by Oreif: Not all ECM's use a paperclip to get into diagnostic mode or read codes. Ford requires you to unplug a connector, Mopar has 2-3 different ways as well. Fail Safe and Limp mode are the same thing. Just different terminology by different manufacturers. With all the cars I have owned, I have never been stranded for a fuel delivery problem with a carb'd engine. It does not mean carbs are better, Just that there are more tools required to diagnose EFI problems which make it harder to locate problems on the side of the road.

exactly why I like OBDI GM computers. Fail safe and limp mode are not the same thing in regards to GM ECM's. They are two distinct failure modes. Limp mode more or less means your ECM has failed and is not running.

With all the cars I have owned, I have never been stranded for a fuel delivery problem with an EFI engine. It does not mean EFI is better, Just that there are more hand tools required to diagnose carb problems which make it harder to locate problems on the side of the road.

Although, I have been stranded for an ignition problem on an EFI engine, but apparently we're not talking about that. Otherwise I'd bring up how barbaric points, condensers, and distributors in general are.

quote Originally posted by ryan.hess: Although, I have been stranded for an ignition problem on an EFI engine, but apparently we're not talking about that. Otherwise I'd bring up how barbaric points, condensers, and distributors in general are.

You didn't say EFI DIS or distributor but there I might argue with you. I have been stranded with DIS problems and ECM failures but never a sensor failure. I never had points fail without some warning and (somewhat) graceful degradation (the cracked distributor caps were the most annoying). Coilpak failures are a degradation and you can limp but if the control module goes you don't. And the annoying part is I have never had the check engine light say anything about a DIS failure. That's how I discriminated between ECM/sensor problems and DIS problems - problem without check engine = DIS problem.

[This message has been edited by Fierari (edited 07-28-2006).]

quote Originally posted by ryan.hess: Limp mode is for a processor or PROM failure. It doesn't even look at the sensors, it just tries to run the engine with hardware. Fail safe mode is for a sensor failure, where a value is given to it to keep the engine running. I can only comment on OBDI GM computers. OBDII GM computers are more sophisticated yet, and have better algorithms to detect bad sensors, but are not foolproof. The great part about sensor failures, is the computer will tell you what's wrong. Had you or your sister read the codes, you might have been able to unplug the offending sensor, and driven home. You can fix a carb system with a screwdriver, wrench, timing light, and vacuum gauge; but you can fix an EFI system with a paperclip. (scantool for OBDII systems)

cant really fix an EFI system with a paperclip, the code will flash, youll see what the code is for, then you have to dignose what caused the code, test multiple systems until you find the bad sensor. Or you can just be a parts thrower and replace the sensor that caused the code and hope whatever caused the sensor to fail goes away.

sensors will cause cars not to run and or die. Ever have a MAF fail? Yeah the car will start, for about 2 seconds then die. My one UTI Instructor (who is an electrical engineer and designed many scantools and scopes for snap-on, fluke, etc.) had a coolant temperature sensor fail on his daughters VW and caused the car not to start.

As far as carbs illegal after 85...? Thats not really true. It may be illegal in say califonia to put a carb on something that came with fuel injection. My caprice is an 88 and last factory carb model. Ive even seen a 1990 Honda still carbed. I have noticed that import cars seem to stick with older technology longer then american cars...but thats another story

quote Originally posted by GTFiero1: cant really fix an EFI system with a paperclip, the code will flash, youll see what the code is for, then you have to dignose what caused the code, test multiple systems until you find the bad sensor. Or you can just be a parts thrower and replace the sensor that caused the code and hope whatever caused the sensor to fail goes away. sensors will cause cars not to run and or die. Ever have a MAF fail? Yeah the car will start, for about 2 seconds then die. My one UTI Instructor (who is an electrical engineer and designed many scantools and scopes for snap-on, fluke, etc.) had a coolant temperature sensor fail on his daughters VW and caused the car not to start.

MAF's suck, plain and simple. Expensive part that isn't necessary, and always breaks.

I'd like to propose a test... I'll pull or short out any sensor you want, and I bet the engine will still run, or I can get it to run with nothing more than a paperclip.

Anybody have any sensor suggestions? I'll test tomorrow when it's light out.

(I should take bets... this could be fun!)

[This message has been edited by ryan.hess (edited 07-28-2006).]

quote Originally posted by ryan.hess: MAF's suck, plain and simple. Expensive part that isn't necessary, and always breaks. I'd like to propose a test... I'll pull or short out any sensor you want, and I bet the engine will still run, or I can get it to run with nothing more than a paperclip. Anybody have any sensor suggestions? I'll test tomorrow when it's light out. (I should take bets... this could be fun!)

Ok pull the crank sensor and cam sensor

fuel injection, not ignition.

quote Originally posted by ryan.hess: fuel injection, not ignition.

..if all ignition input to the ECM is cut off the motor shouldn't remain running.

[This message has been edited by Erik (edited 07-29-2006).]

Ill agree that electronic ignition is much better than points for most aps. Out of LOTS of cars ive had for 40 years though, I never was left totally stranded ever in a carbed car with distributor w/ points. Sure they would quit, but 10-15 minutes got you back running with a screwdriver and fingernail file. Diagnostics at the side of the road consisted of looking in the carb for gas and checking at the plugs for spark. Ive been stuck many times with newer cars with FI/ electronic ign. Repair usually is a with a phone, tow truck, and if you were far from home....a huge bill. I had to get one of the girls cars running for her that quit and even with my free labor, 4 fuel injectors were almost $400 on a $2000 Cavalier.

quote Originally posted by ryan.hess: but you can fix an EFI system with a paperclip. (scantool for OBDII systems)

Yes, don't try to use a paperclip on an ODBII system (don't ask me how I know )

quote Originally posted by ryan.hess: fuel injection, not ignition.

some use crank/cam sensors for injector timing and pulse width also