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76Datsun280z

Sticky EFI thread, please chip in FI guys!

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Since there has always seemed to be a lot of threads with people in need of help with their 280z EFI systems, I have come up with an idea that might get those people in need of help on the right track and give them a little basic knowledge about how the fi's on these cars work! This in return would give us a break on not having to explain everything and how the efi system work so often as they could refer back to the sticky post for those types of questions. Not only this, but they could refer back that post for example and they will know what the parts are called so there wouldn't be anymore of the "black part on the top left", but the actual name and part so we would know exactly what their talking about the first time. I'm not however implying that this post would be all the answers to all their techincal questions, that's not the point of it. The point is to give them a basic understanding of how the Bosch efi system works on these cars and what the parts are called before they ask their question. That's why the sticky post would be called "Please read before you post your efi question" at the top of the help and fi sections of the forum.

Basically this might include a link to the atlantic Z car page and a link to the the efi bible. Better yet, a diagram that shows the names of all the parts on the fi system that could be posted right into the post so it's easier to refer to for part names without clicking the links. I would do this from my book, but my scannor I can't seem to get my scanner to work.

Before I posted this, I pm'd Stephen (sblake01) as he is our big fi guy here on the board and he thought that is was a good idea so I forwarded the message to Mike who in return liked the idea. There are down sides to everything, and like Stephen mentioned, different model years differ and sometimes these cars get tampered with by previous owners. This is why it would be great if all you efi guys could chip in and post links, diagrams information, common problems (all efi related) or whatever you feel is necessary to be included in this post. Please keep it as simple as possible. Since a lot of us own different years of 280Z's, you might have some stuff to chip in on here as you're familiar with that particular year of car. Hopefully you see what I'm getting at.

I will wait maybe a week or so and this will go you all a good chance to post what you want into the post. Once this is done, I will copy and paste everything into one post and send it to Mike who in return be the one to make the sticky post.

Like I said my scanner is not working at this time to post that diagram of the efi names and pictures of each part, but will keep working on it. Here are the links to the EFI bible and the Atlantic Z car page. I will start off:

Electronic Fuel pump- Pumps fuel from the tank to the engine

Fuel Damper- Acts as "muffler- that is, it keeps pressure surges from making noises which could be heard by the driver

Fuel Filter- Filters out particles in the fuel before reaching the inectors

Fuel injector- Spray fuel into the combustion chamber

Dropping Resistor- Causes a voltage drop so that the injector operates on less battery voltage and also protects the injector from voltage surges coming from the alternator from the effects of other parts in the electrical system.

Electronic Control Unit (ECU)- Controls the injectors by turning their ground on and off. Governs how much fuel is injected by holding the injectors open for longer or shorter periods of time.

Fuel Pressure Regulator (FPR)- Keep the pressure in the fuel system to a constant 36 psi.

Air Flow Meter (AFM)- Measures the amount of air coming into the intake mainifold. The more air passing through, the farther the flap inside will be pushed open.

Idle speed screw- Use it to adjust the idle speed

Throttle Position Switch(TPS)- Contains a set of contacts inside that tell the ecu if the engine is either idling or declerating.

Water Temperature Sensor- Allows the ecu to richen the mixture until the engine arrives at opperating temperature.

Air Temperature Sensor- Measures the temperature of the air coming in from the air cleaner.

Cold Start Valve- A seventh injector to add additional fuel on a cold start up. Only gets current when the starter is cranking.

Thermotime Switch- Opperates according to both temperature and time. (Hopefully somebody can come up with a better definition than that).

Air regulator- Allows the engine to be at a fast idle to aid in warm up.

http://www.atlanticz.ca/zclub/techtips/EFI&fuel.htm

http://www.atlanticz.ca/zclub/techti...ectionbook.pdf

http://www.atlanticz.ca/zclub/techti...e_Bulletin.pdf

Please chip in what you would like to see in this post!

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I would suggest putting a photo of each of the EFI components and then also a larger shot of the engine bay with them labeled.

Since I suggested the idea I will also implement the idea to ... just won't happen till Monday or Tuesday as I have work all weekend long.

On a better note, my car is now registered, licensed and insured to terrorize the Belgian roads ... that only took 6 months to complete!

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Great info from you both, my car runs great now but you never know. The info is always helpful.

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Thermotime Switch- Opperates according to both temperature and time. (Hopefully somebody can come up with a better definition than that).

the thermotime switch controls the cold start valve, by changing the ground as the engine heats up. turns the cold start valve off so it doesn't have a rich mixture a long time after startup.

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Actually, the thermotime switch has a coil that begins to heat up when it gets a signal from the starter but only when the coolant temperature is below 35 deg. C. and will only operate for a maximum of 8 seconds at which point the cold start valve will close. It really doesn't have anything to do with the mixture other than allowing the fuel to flow through the cold start valve during that duration.

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Thanks gusy,

Since I suggested the idea I will also implement the idea to ... just won't happen till Monday or Tuesday as I have work all weekend long.

That would be great!

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For any 280z owners that are in need of fuel injection help, please refer to these links and information given on this page before you make a post in the help section so you will have a better understanding of how the fuel injection system works on your car. By doing this, it will in hope give you a better understanding of what the problem is and when you do post your question, it will in return give our fuel injection guru's a better understanding of what the problem is on your car.

img1192eo7.jpg

Electronic Fuel pump- Pumps fuel from the tank to the engine

Fuel Damper- Acts as "muffler- that is, it keeps pressure surges from making noises which could be heard by the driver

Fuel Filter- Filters out particles in the fuel before reaching the inectors

Fuel injector- Spray fuel into the combustion chamber

Dropping Resistor- Causes a voltage drop so that the injector operates on less battery voltage and also protects the injector from voltage surges coming from the alternator from the effects of other parts in the electrical system.

Electronic Control Unit (ECU)- Controls the injectors by turning their ground on and off. Governs how much fuel is injected by holding the injectors open for longer or shorter periods of time.

Fuel Pressure Regulator (FPR)- Keep the pressure in the fuel system to a constant 36 psi.

Air Flow Meter (AFM)- Measures the amount of air coming into the intake mainifold. The more air passing through, the farther the flap inside will be pushed open.

Idle speed screw- Use it to adjust the idle speed

Throttle Position Switch(TPS)- Contains a set of contacts inside that tell the ecu if the engine is either idling or declerating.

Water Temperature Sensor- Allows the ecu to richen the mixture until the engine arrives at opperating temperature.

Air Temperature Sensor- Measures the temperature of the air coming in from the air cleaner.

Cold Start Valve- A seventh injector to add additional fuel on a cold start up. Only gets current when the starter is cranking.

Thermotime Switch- the thermotime switch has a coil that begins to heat up when it gets a signal from the starter but only when the coolant temperature is below 35 deg. C. and will only operate for a maximum of 8 seconds at which point the cold start valve will close. It really doesn't have anything to do with the mixture other than allowing the fuel to flow through the cold start valve during that duration.

Air regulator- Allows the engine to be at a fast idle to aid in warm up.

http://www.atlanticz.ca/zclub/techtips/EFI&fuel.htm

http://www.atlanticz.ca/zclub/techti...ectionbook.pdf

http://www.atlanticz.ca/zclub/techti...e_Bulletin.pdf

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My shout is Great Idea! I'm one of those guys who will be studying it. Thx!! (71' 240w/83zxt transplant)..

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Great idea!! First question it appears.....just bought a 76 280z. runs well for about 15 minutes and then runs rough. feels like it's running rich and flooding out. i'm leaning towards a temp switch, but it doesn't sound like the thermotime switch is the bad guy based on what i've read here. any other ideas??

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I'd lean towarards the water temperature sensor or it's connection. If it were the thermotime switch, it would take less that 15 minutes for the symptoms to show since that would likely lead to constant flow through the cold start valve.

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I just had my car on a lift to check the fuel pump strainer. I should've had my camera to get pics of the pump & damper for ya. :stupid:

I'll get you pix of the other things first.

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Thanx Stephen.... i was leaning that way as well. I hate chasing electrons.....is that switch NC or NO? If it's NO, I should be able to jump it and fool the system.

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It's not a switch. It's a thermister (I think that the electrical term). It starts with a higher resistance when the engine is cold and decreases the resistance was the coolant temp rises. It changes the fuel enrichment and fuel injection pulse as the engine warms up. If you jump it I'm not sure that will accomplish what you're trying to accomplish.

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nope, it won't. and thermistor is correct. they were all over the airplanes i worked on. thanks!!

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I've come up with a way on the EFI cars to help pinpoint a common problem. Using my fuel injection cannister cleaner the other day to clean out the injectors on my daughter in law's car (non Datsun), it dawned on me that I could fill the cannister with gasoline, set the pressure in it to 36 or so, attach it to the fuel rail, unplug the fuel pump relay so it doesn't pump, and run the car off the cannister. If the car runs right off the cannister, but not when normally hooked up, then the problem is either in the tank or lines or the fuel pump itself. Not sure I explained that clearly enough, but at least I understand it.

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This is the fuel injector cleaning tool that I mentioned in the previous post. The first tip is for the EFI cars. The cannister connects to your air compressor and the fuel pressure can be set with the regulator on top of the cannister. Attach it to your fuel rail where the line from the fuel filter goes, plug the return line below it, unplug the fuel pump relay, set the fuel pressure to about 30psi, open the valve on the bottom of the cannister, start the car, and let it run until the solvent runs out. Next to it is the cleaner I use. It's important that you plug the return line as you don't want the solvent to get in the gas tank. It's also important to disable the fuel pump so it doesn't pump fuel from the tank during the operation.

The other can to the right is used to decarbonize. This can be done on EFI or carbed cars. Without the compressor connected to the cannister and it's pressure regulator turned off, connect the cannister to a vacuum port on the intake such as the one for the brake booster, start the car and slowly open the valve on the bottom of the cannister and little by little let the decarbonizer into the port. If you let too much in at one time, the engine will stall. It'll smoke like crazy until all of the solvent clears but, when you're done, your piston tops, valves, and combustion chambers will be clean.

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Isn't that pretty much the same a SeaFoam? How can you tell things are decarbonized Also, do think it would hgurt if you de-carbonized twice or twice in one summer (like once a month)?

thxZ

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Pro Inject-R Kleen is just what the name implies. D-karbonizer is similar to Seafoam but stronger. As in you only have to do it once. Seafoam could take two or more applications. I used to use Seafoam but I like the results with OTC's products. Are you asking how can you, as in anyone, tell if things are decarbonized or how can I tell? I use a boroscope. A rather pricey tool but I've used it enough to cover the initial cost. I don't think it would 'hurt' anything to do it twice in a month with seafoam but it's not necessary. I do the D-karbonizer treatment and the fuel injection cleaning about once every year and a half or so.

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Rigid tools puts out an inexpensive, like 230-250 bucks, digital borescope used for looking into plumbing and closed spaces. It's way cheaper than a normal borescope and the 2 x 3 viewing screen is easier on the eyes. The head is about 1/2 inch in diameter, but should fit thru most, if not all spark plug holes. You can't really direct the head at all, but it comes with a mirror attachment and a magnet attachment. Great for finding the screw you just dropped into the cylinder..... I've used the high dollar scopes to inspect the innards of jet engines and the real cheapies to look at turbine wastegates on recip round and flat motors during my years as an aircraft mechanic. These are a good mid range scope. Any decent hardware or plumbing shop should be abale to get them.

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hey guys i have a question i have had my car for a year and a half now and i had been troubleshooting it and i came down to the conclusion that the ECU is bad and i need to replace it, anyways i went to autozone to order a replacement and they only sell remanufactured ECU's well i waited a week to get it and when i got it i first realized that the one i bought was alot different from the orignal, the one i bought is longer and has missing pins where you would connect it to the Harness the part number on the one i bought its A11-600-000 and the orignal part number is A11-100-002 i was wondering will the one i bought work on my car? or where should i go so that i get the correct ECU that is the same as the orignal? any answers would be a great help

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The missing pins would bother me. Auto parts stores sell generic ECUs and I doubt if that one would work properly in your car. I know where a 76 ECU is but I don't know if it works or not but I assume it does because it's not the reason the car no longer runs as it is a friend's parts car. If you want me to check into it, let me know.

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thanks stephen for the information i searched today and on MotorsportsAuto.com i found that i could order the exact one i need for around $200 but i would be interested in the one that you have, and if im not mistaken the 76 and 75 ECU are interchangable? i ask this because my car is an early 75 but i would still be happy to have any info about the ECU you have knowledge about

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