Another EFI problem

[jonathanrussell]

I just think it's important to use the correct terminology especially when responding to someone who, at least by the content of his post is not as experienced with the system and it's troubleshooting as you or I or many others on this site. I won't say anything else along those lines here since it seems to bother you so much.

Fair enough. I will try to use the right terminology in the future if I am going to give my suggestions.

[EdMo]

I appreciate any input I can get, even though some is over my head... and you are correct of me not knowing the system well enough to understand it all. I can say that I understand it much more now than I did a few days ago...because my car is going on near 30 years old and not ran much in the last 11, except for the 600 miles I've put thus far after rebuilt engine. I think that I will replace the Thermotime first and see what this does, then if needed try the cold start valve since both are the original parts. The connectors mating to them are also the originals and kinda look bad...I've tried to clean but they still show green build up and do not sit snug in the mating connectors, I've got these on order from Bonzai. I know what the problem has not been thus far, so that once it is resolved, maybe we can come to a consensus of what the problem really was. Hopefully someone else will also benefit from this bug later. Thanks.

[sblake01]

Those connectors are important and are likely the source of at least some of your problems. Did you use some type of electrical contact cleaner like DeOxit or CRC QD? Those will remove the build up but won't do anything about the looseness. We've done threads on replacing them with better than stock connectors from BMWs, Volvos, etc. Here's one. Note the pictures in post #21 and #30:

http://tinyurl.com/2u8ocn

[sblake01]

I think that I will replace the Thermotime first and see what this does, then if needed try the cold start valve since both are the original parts.

I'd suggest testing the items first. If they test good there's no need to replace them.

[justinr54321]

EdMo,

Replace the cold start valve first. I talked to a friend with a similar problem, and his cold start valve was bad, it was sticking causing too much fuel and once warmed up, did the exact same thing your was doing. This wasn't on a Z, but was on an 82Toyota Celica.

Justin

[TomoHawk]

My engine is running well, and starts easily, and I don't even have the cold-start injector (or valve) connected. So I think even if you want to work on something else and just leave it unconnected for now, you should be able to get the engine started & running for whatever time you would need to work things out. The weather in TX should be warm enough that you wouldn't need the use of that injector.

In the meantime, I tested the thormotive switch, temperature sensor, and some other stuff, and I replaced the ones that weren't working right.

FWIW- I still have the cold-start injector installed, and the connector will be plugged on, once I put a new one on, but I plugged the fuel hose going to it, and I won't worry about it, since I only drive the car when it's warm.

thxZ

[sblake01]

You do realize that witout the cold start valve connected, your thermotime switch sends an electronic signal to nowhere. If you're going that route, I'd disconnect it too. No need to run current through it. It's been my experience with thermotime switches that the heater (electrical side) fails more often than the water termperature side.

[TomoHawk]

Yes, I have the cold-start injector/valve completely disconnected for now. It looks odd ( if you are familiar with that engine) if you see the plug hanging there, so when I put the new connector on it I will cut one wire so a simple butt connector can complete the circuit if I want to use that injector again.

But unless I am at a Z car show, I should disconnect the thermotime switch too; there's no need to have current running through the heater inside constantly.IIRC, it's connected via two bullet connectors to the main sensor harness.

thxZ

[sblake01]

I think you missed my point. If your thermotime swicth is still connected, you're still getting a signal to it everytime you crank the car below 72 degrees. You should disconnect it also since that signal goes nowhere with the cold start valve disconnected.

[sblake01]

Actually, now that I think of it, you could leave the cold start valve connected and pull the connector from the thermotime switch. It would serve the same purpose. Your csv wouldn't get a signal and your ts wouldn't have the heating coil activated everytime you crank the car below 72 degrees.

[TomoHawk]

I have my thermotime connector on the switch itself, but the one wire to it is disconnected at the bullet connector ( under the fuel rail.) There's no need to keep that little heater inside constantly hot. It gets connected for car shows where people might notice an unconnected wire on the engine.

So right now I have both disconnected.

[EdMo]

O.K all .... it's resolved finally. I went ahead and first disconnected the cold start valve and ran for a while and in idle, it bogged down and shut off as its was doing before. So figured that was not the culprit...next went and replaced the Fuel Pressure Regulator and with that seemed to be the problem. It ran fine and I let idle for 10-15 minutes and never even tried to bog down. So far so good .... again thanks to all. I learned from this tremendously, now I can take the cold start valve and get my mula back....over 100 bucks...yahooo!