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.

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

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.

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.

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

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.

What are you looking at wit hthe borescope? just the piston-tops?

Piston tops, valves, combustion chamber. etc. Whatever you can see.

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.

I just noticed my typo up in my post. That, of course, is borescope not boroscope. Speaking of inexpensive scopes, check this out, a frend sent me the link the other day:

http://www.1800endoscope.com/pencam.htm

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

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.