Engine control computers an opinion

slant6billy · Aug 12, 2012

OK, so when someone like a company or government says," Trust us, this is good for you.", You know it is bad and going to hurt. When Mopar went to leanburn in 79 and kept it until OBD1 and then in 1990, the EPA said by 1996 all cars will have tattletails called OBD2. For the last 3 weeks my 1995 van with a 3.9 has struggled to start. After several sensors, I had to buy a refurbed OBD1 (smeared silicone and all). So the van runs great after much frustration. Leanburn was never a peach either. My F- body has the 5 wire mopar ignition - Chrome box and started right up today with a little shot glass of 87 octane dumped in the carb. Now she has sat since May with paper on the windows as I put down the etching primer. I would love to get her registered this month and get vanity plates of: "F- BOMB" or "F- BIRD" in retaliation to oppression of computer controlled crap cars. I'm a degreed electrical engineer and I really can't stand over complicated crap for no good reason.

MoparTex · Aug 12, 2012

I agree!

I'm glad the leanburn was already gone on my mirada. I won't feel bad at all as I restomod the heck out of it. You can add overly complicated vacuum systems to the list of garbage. I believe these cars when stripped of all that crap run better, cleaner and get better fuel mileage than the typical vacuum leaking, de-tuned non properly maintained scrapheaps roaming our streets.
Keep the gooberment out from under my hood!
O.K. off my soapbox now. .........Sorry for the rant.lol

roadrunnerman · Aug 12, 2012

Has anyone heard any more on the government putting computer shut down control in the newer cars so the cops and other enforcement can stut down a car in a high speed chase?

slant6billy · Aug 13, 2012

Well, RRMan, if you own a GM product that has, had or was optioned with Onstar, it has emergency shutdown. My friend's 2009 caddy was jacked and the little bastards were not only shutdown, but Onstar locked the doors with the little bastards inside crapping themselves. I'll never own a GM with that option. Insurance companies, such as Progressive have "snapshot" insurance. They plug into the OBD2 portand watch how you drive. First off, if someone is riding in my glovebox (government or other), they better come up with some gas money. If I want to waste some rubber, nobody should know about or care - if JohnLaw didn't see it, it didn't happen.... not that I do that type of thing.

Jack Meoff · Aug 15, 2012

Although I do like the fact that OnStar can shut down your car
And trap little pukes inside.
You gotta wonder if they can listen in on what you're saying in your car
And obviously they know where you are at all times.
Big Brother.

Master M · Nov 29, 2015

slant6billy said:
OK, so when someone like a company or government says," Trust us, this is good for you.", You know it is bad and going to hurt. When Mopar went to leanburn in 79 and kept it until OBD1 and then in 1990, the EPA said by 1996 all cars will have tattletails called OBD2. For the last 3 weeks my 1995 van with a 3.9 has struggled to start. After several sensors, I had to buy a refurbed OBD1 (smeared silicone and all). So the van runs great after much frustration. Leanburn was never a peach either. My F- body has the 5 wire mopar ignition - Chrome box and started right up today with a little shot glass of 87 octane dumped in the carb. Now she has sat since May with paper on the windows as I put down the etching primer. I would love to get her registered this month and get vanity plates of: "F- BOMB" or "F- BIRD" in retaliation to oppression of computer controlled crap cars. I'm a degreed electrical engineer and I really can't stand over complicated crap for no good reason.

Yes Yes and YES. I just posted an engine computer question, and then I saw this post. Computers in cars suck.

metallicaman0258 · Dec 1, 2015

Being (potentially) much younger than you guys I must put my two cents in. Computers in cars DON'T suck. Carbs suck. They are finicky, fickle, inefficient metering devices that were sent to the scrapheap in the sky for good reason. Is it too cold? Adjust. Is it too hot? Adjust. Humidity too high? Adjust. Oh and by the way, hope its not crazy hot because you will boil the fuel in the bowls and lean out. also hope you aren't doing crazy sideways or hill action because the bowls will flood and you will choke out.

These above reasons and situations are the reason I am a proponent of EFI. All the measurements and adjustments are made and set on the fly by the computer so you don't have to stop in Kansas on your Denver to Miami trip to reset mixture and timing. Also it either runs or doesn't. the reliability aspect of EFI is its main selling point for me personally. Turn the key, fuel is pressurized, crank and go. Not pump pump pray. Yes, there are sensors, wires, inputs, outputs, computer(s), multiple coils and acres of plastic (in some cases), but after you learn the basics its usually replace a sensor and go. Its a lot easier (albeit possibly more expensive) than having to check and recheck resistances and voltages to find you why at WOT 3500 rpm the spark isnt hot enough because the springs in the distributor are wrong causing the wrong advance.

Before you go all crazy on me, I've had over 30 vehicles in my life and in all states of tune. I've had EFI that runs worse than a vapor locked 350 in the desert. I've also had cars with carbs that start as soon as you hit the key no pumping required. This is just my preference and experience.

Sorry, Ill go back to my cave.

slant6billy · Dec 1, 2015

metallicaman0258 said:
Being (potentially) much younger than you guys I must put my two cents in. Computers in cars DON'T suck. Carbs suck. They are finicky, fickle, inefficient metering devices that were sent to the scrapheap in the sky for good reason. Is it too cold? Adjust. Is it too hot? Adjust. Humidity too high? Adjust. Oh and by the way, hope its not crazy hot because you will boil the fuel in the bowls and lean out. also hope you aren't doing crazy sideways or hill action because the bowls will flood and you will choke out.

These above reasons and situations are the reason I am a proponent of EFI. All the measurements and adjustments are made and set on the fly by the computer so you don't have to stop in Kansas on your Denver to Miami trip to reset mixture and timing. Also it either runs or doesn't. the reliability aspect of EFI is its main selling point for me personally. Turn the key, fuel is pressurized, crank and go. Not pump pump pray. Yes, there are sensors, wires, inputs, outputs, computer(s), multiple coils and acres of plastic (in some cases), but after you learn the basics its usually replace a sensor and go. Its a lot easier (albeit possibly more expensive) than having to check and recheck resistances and voltages to find you why at WOT 3500 rpm the spark isnt hot enough because the springs in the distributor are wrong causing the wrong advance.

Before you go all crazy on me, I've had over 30 vehicles in my life and in all states of tune. I've had EFI that runs worse than a vapor locked 350 in the desert. I've also had cars with carbs that start as soon as you hit the key no pumping required. This is just my preference and experience.

Sorry, Ill go back to my cave.

I somewhat agree with your side on that. Carbs can be frustrating. It is a lost art and I am not Picasso. The OBD0, OBD1, ODB2 and lean burn/ lean spark was a ill fated attempt to make things in control. OBD2 is not your friend. It is a tattletail bastard reporting things like loose gas caps and evap canisters over purged. The technology is there to make life easy, but is more of a money maker and put upon the consumer. I own a OBD1 - a 95 Ram Van 2500. It is a great truck and beats emissions every year. No tattletail stuff on it. I'd rather run a 300 dollar edelbrock right out of the box and get all the driveability I need. I do think since Latin is still taught in schools, carb rebuilding should be as well and the physics behind the carb. I wish I had that class back in school. It would have been one I'd stay awake for.

Jack Meoff · Dec 1, 2015

Call me old school but I'll take a carb anyday.

Master M · Dec 1, 2015

metallicaman0258 said:
Being (potentially) much younger than you guys I must put my two cents in. Computers in cars DON'T suck. Carbs suck. They are finicky, fickle, inefficient metering devices that were sent to the scrapheap in the sky for good reason. Is it too cold? Adjust. Is it too hot? Adjust. Humidity too high? Adjust. Oh and by the way, hope its not crazy hot because you will boil the fuel in the bowls and lean out. also hope you aren't doing crazy sideways or hill action because the bowls will flood and you will choke out.

These above reasons and situations are the reason I am a proponent of EFI. All the measurements and adjustments are made and set on the fly by the computer so you don't have to stop in Kansas on your Denver to Miami trip to reset mixture and timing. Also it either runs or doesn't. the reliability aspect of EFI is its main selling point for me personally. Turn the key, fuel is pressurized, crank and go. Not pump pump pray. Yes, there are sensors, wires, inputs, outputs, computer(s), multiple coils and acres of plastic (in some cases), but after you learn the basics its usually replace a sensor and go. Its a lot easier (albeit possibly more expensive) than having to check and recheck resistances and voltages to find you why at WOT 3500 rpm the spark isnt hot enough because the springs in the distributor are wrong causing the wrong advance.

Before you go all crazy on me, I've had over 30 vehicles in my life and in all states of tune. I've had EFI that runs worse than a vapor locked 350 in the desert. I've also had cars with carbs that start as soon as you hit the key no pumping required. This is just my preference and experience.

Sorry, Ill go back to my cave.

I can see some of your points. In my experience I have had way more trouble and expense with computers on cars than carbs. I am confident competent engineers looking to simplify a fuel injection system for cost and reliability could produce it. Fuel injection would be welcome if it was designed to be the most cost effective possible for the owner of the car. The most recent computer problem I had was with an OBDII system. Overdrive light flashing routinely, engine light on. Scanner tool would turn the engine light off, but it would reappear in a few days. Transmission shop used their mega dollar scanner tool which produced the result of transmission electronic valve body malfunction for the mere cost of $700.00. I did the job myself for $100.00. Wrong ! that was not the problem. Next up was the engine scan tool said solenoid emission valve malfunction, $180.00. Wrong ! not it either. I went online for hours searching for the real problem. Someone posted the exact vehicle year make model with exact problem. After that person spent over $3500.00 to have his problem traced it was low and behold the main ECU computer failure in the firewall. It didn't know it was malfunctioning. I had to remove the inner fender to get to the computer. I replaced the computer and that was it. This is a one owner car with 45,000 original miles and always garaged. Something should be done to have to go through all that expense and work to have a system atomize my fuel for me.
I thing OBD ( One Big Dummy ) designed this system.

metallicaman0258 · Dec 1, 2015

All of you have valid points and I recognize and agree with most.

Slant6billy, OBDII is a generic set of diagnostic code put on all vehicles produced in 1996 and thereafter. It was simply designed with diagnostics in mind and to be used strictly as a guide to attempt to figure out the problem at hand. There are still steps to take after reading the codes to diagnose the problem 100% Before OBDII standards were created by the SAE every manufacturer had a different way of accessing codes for their machines OBDII was a standardization so a set type and amount of data could be accessed, aiding in the diagnostic process.
I agree it is a tattle tale little $hįť "that's just so every system can run at peak efficiency" You should see how many systems I have to deal with on new Volvos at work. OY VEY!!

MasterM, look at MSD Fast XFi and Edelbrock bolt on 4bbl EFI throttle bodies to find a cheap reliable setup. Cheap being a relative term. And as for the $3500 before a simple repair, that's the result of the "technician" not following procedure properly and assuming the computer knew it all. Unfortunately this happens way too often in the flat rate mechanic world because mechanics don't want to take the time to properly diagnose the problem as it will cut into their paychecks.

I hope we can all agree on somethings and disagree on others. I'm glad we can have an intelligent coherent conversation with each other without killing morale

Slanté!

Jack Meoff · Dec 1, 2015

metallicaman0258 said:
I hope we can all agree on somethings and disagree on others. I'm glad we can have an intelligent coherent conversation with each other without killing morale

Slanté!

And that is the beauty of this place.

Master M · Dec 1, 2015

metallicaman0258 said:
All of you have valid points and I recognize and agree with most.

Slant6billy, OBDII is a generic set of diagnostic code put on all vehicles produced in 1996 and thereafter. It was simply designed with diagnostics in mind and to be used strictly as a guide to attempt to figure out the problem at hand. There are still steps to take after reading the codes to diagnose the problem 100% Before OBDII standards were created by the SAE every manufacturer had a different way of accessing codes for their machines OBDII was a standardization so a set type and amount of data could be accessed, aiding in the diagnostic process.
I agree it is a tattle tale little $hįť "that's just so every system can run at peak efficiency" You should see how many systems I have to deal with on new Volvos at work. OY VEY!!

MasterM, look at MSD Fast XFi and Edelbrock bolt on 4bbl EFI throttle bodies to find a cheap reliable setup. Cheap being a relative term. And as for the $3500 before a simple repair, that's the result of the "technician" not following procedure properly and assuming the computer knew it all. Unfortunately this happens way too often in the flat rate mechanic world because mechanics don't want to take the time to properly diagnose the problem as it will cut into their paychecks.

I hope we can all agree on somethings and disagree on others. I'm glad we can have an intelligent coherent conversation with each other without killing morale

Slanté!

My comments are just based on my experiences alone and not an overall opinion I have. I enjoy the enlightening
conversation, and thank you for your input. That $3500.00 repair that guy had was done at a dealership.

kkritsilas · Dec 1, 2015

metallicaman0258:

You have a point with modern factory fuel injection systems. You are way off base when it comes to the Lean Burn system in our cars. Lean Burn/ESA was an attempt, and not a really successful one, at meeting increasingly strict pollution and fuel economy requirements. When it ran well, it robbed driveablity and power. When it went bad, it not only did that, it also ran rough, or on some occasions, not at all. Unless you had the factory specific diagnostic equipment, you also had to resort to changing parts one by one until you found the problem, if you ever did. There is no OBD connector of any type around, nor are there any standardized diagnostic codes available. The Lean Burn/ESA can be seen as a fore-runner of today's computer controlled fuel injection/ignition, but from another perspective, they are nowhere near similar to each other. Lean Burn/ESA was an interesting concept, but the electronics of the day were in no way up to the task (goes for all engine control computers of that era). Today's cars are another thing entirely, and to compare the cars of today, with the Lean Burn/ESA system is like comparing a 1981 PC to today's PC. I am comparing the ESA/Lean Burn to today's fuel injected systems, because the Lean Burn/ESA was what was in the cars that this site is about.

Carburetors are not as bad as people think they are. They can work wonderfully, and when tuned right, can also drive quite well. Do they work better than the fuel injection systems of today, factory or third party? No, no way. Do they work well, when properly tuned up? Yes, and they had for many, many years before fuel injection became common. Will going to a standard carb work better than the Lean Burn/ESA systems that came in our cars? In the vast majority of our cars, definitely yes, and they won't cost $2-3K to do that, either. Sure, you can put on a third party fuel injection system, and maybe get better driveability, and maybe better fuel economy, but again, it is a $2-3K hit to the pocket book, and about a day or so of work to get it all hooked up (at least for a FAST EZ-EFI). With this, it still remains for the engine to be properly tuned, which is still necessary, even with the "learning" fuel injection systems. Out of the box, they are set up to run very rich, and must be leaned out. It may be somewhat easier to do that with a handheld controller vs. changing jets, but time still must be spent doing it. And chasing down transitional problems is just as time consuming as it is on a carburated car.

No flaming or criticism intended, I just feel you are comparing apples (FMJ Bodies) to oranges (modern cars).

metallicaman0258 · Dec 2, 2015

kkritsilas,
I didn't mean to compare LB with OBD systems. I fully understand that they are stand alone fuel/spark computers with no self diagnostics. the early FI cars of the same era (K, P, etc...) had the OBDI system and it was different from the Fords, Chevys, Volvos, Subarus, etc. thats the point I was trying to make. I also agree with you that a properly tuned carb'd vehicle is just as good as an EFI

I had an 87 Cadillac Fleetwood Brougham with a 4bbl QuadraJunk with wires growing out of it too. That thing was an electrical nightmare. It was 20 years old when I got it and the mice had been living under the hood for at least 5 because that's how long my grandfather had it in the barn. I also have had 3 VW rabbit/golf models from the 80s one with mechanical and the other 2 with electronic fuel injection and they never gave me the problems almost all of my carb'd cars had. The two later golfs had stand alone ECUs to control their systems too. I am also a self proclaimed fanboy of Bosch CIS systems so I may be somewhat biased!

Just to sum up, for me at least, EFI or mechanical FI is the way to go, efficiency, driveability, and most of all adaptability. I guess my main grumble is having to get under the hood and turn a few screws.

Nuttyprof · Dec 6, 2015

EFI is great if it is working properly, but if it quits, you're dead in the water. Carbs are good when working properly, but pretty much no matter what you can bodge a way to get home, not pretty, maby not safe, but home.

Cordoba1 · Dec 6, 2015

Nuttyprof said:
EFI is great if it is working properly, but if it quits, you're dead in the water. Carbs are good when working properly, but pretty much no matter what you can bodge a way to get home, not pretty, maby not safe, but home.

I heard this a whole lot when EFI was coming on line during the 80's, but save for a few systems (It's NOT time for Imperial!), EFI systems are bulletproof. Even today, lots of people upgrade their older cars by taking EFI systems off of 80's and 90's GM cars. Those throttle-body systems are very reliable. Sure, you have an occasional bad injector; but save for a bad fuel pump, most failures wont strand you.

kkritsilas · Dec 7, 2015

Fuel injectors won't strand you, but a bad sensor will (which doesn't really exist in carburated cars) and in a lot of cars, they won't start. In many cars, it won't tell you what is wrong either. In my 1995 Dodge Caravan, I had something go wrong. Looked at the Haynes manual, no go. Online forums said change the camshaft position sensor. I did that. No go. No diagnostic codes, Just no start. Van was old enough I didn't care at that point, but the "bulletproof" statement is far from true. In cars with port fuel injection, in which the computer also handles the ignition, a bad sensor will leave you on the side of the road.

As for throttle body fuel injection systems, they don't exist, in today's factory cars. As for throttle body injected retrofits, I don't see that happening. The 1990s throttle body injection systems weren't really performance oriented, nor do they have much aftermarket support (in terms of performance tunes/fuel maps. or even the ability to actually change the tunes/maps).

Cordoba1 · Dec 7, 2015

I guess I'll consider myself lucky, then. The modern cars I've owned have been far more reliable than the old ones. I love my Cordoba, but if I'm talking a road trip, and it is absolutely critical that I get there, I'll grab the keys to the new car.

I've been studying up on EFI retrofits. There is actually quite a bit of support from the traditional makers of carbs; now getting into the bolt-on EFI game. There's also a remarkably large group of do-it-your-selfers using (the afore mentioned throttle body systems) junkyard parts to upgrade older engines to EFI. Do a search on "Megasquirt" - fun stuff! It's mostly older, batch-fired tech -- but it's those easy to work on setups that makes the conversions pretty easy.

Some time ago, I bolted on a gen-1 Holley Pro-Jection system on to a 318. It was surprisingly easy, and really did provide that turn key / car starts / drive off experience that makes EFI such a great thing. I bought it used on eBay. Those bolt-on systems are getting simpler and easier to install, too. I wish I had bucks to throw in a turn key / EFI engine into my 'Doba!

I keep second guessing the project, though, because my current carb setup is actually tuned fine. It starts right up after setting the choke, and works without issue.

kkritsilas · Dec 7, 2015

I participated in a FAST EZ-EFI 1.0 install on a Chevy small block powered 1951 Mercury sedan. Install took a day, including fuel system hookup, the installation of the bung for the O2 sensor in the exhaust, electrical hookup, and initial tune. I have helped refine the tune three times since. Out of the box, the air/fuel ratio was way rich. Had to lean that out. Second time around, tune had to be redone because the idle speed was wandering due to an unstable tach signal from the distributor (even though the little filter box was being used). Third time, further leaning out the Air/Fuel ratio, along wit programming the fan outputs to come on at the right temperature. Still trying to improve a very slight hesitation when the throttle is pushed wide open from low speed. Generally works better than the previous Edelbrock 4 barrel. Owner says it gets a couple of MPG better fuel economy, but no discernible power increase, even though it is advertised as adding horsepower.

This is easy on a turn key system. The Megasquirt is very much a lego set; lots of trial and error, lots of things to figure out on your own.

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