1985 Spider starts rough and dies

[Darsella1]

Sorry you are having so much trouble.

If all else fails, you could always try this:

http://www.seafoamsales.com/motorTuneUpTechGas.htm

Seafoam - you can buy it almost anywhere for around $8.00:

* Cleans fuel injectors
* Cleans carburetor jets
* Cleans carbon
* Stabilizes fuels
* Upper cylinder lube
* Removes moisture in fuel
* Frees sticky lifters
* Frees sticky rings
* Removes moisture in oil
* Cleans P.C.V. systems
* Cleans catalytic converter odors
* Oxygen sensor safe

Although I am not the expert that these guys are.

Our '67 Camero sat in storage for 10 years and we have no idea what was & was not drained or taken care of. We had all sorts of issues. We put it in the fuel tank and and it worked like a miracle. Seriously, it went from un-drivable to running. Ray says he uses it all the time on a lot of customer cars. We also use it over the winter as a fuel stabilizer.

Also, just because the car is original does not mean it did not have some funky issues from when they built it. My car had a few key things installed from the factory backwards. Including the engine fan. Scary right? They must have been in a hurry to get those Cadillacs on the line!

[Daveje]

Thanks Darsie, I'll get this thing running soon enough but I gotta admit it's frustrating. I'll try the Seafoam, I actually passed it up on Saturday at the auto parts store after the guy behind the counter was swearing by it. Guess I should have bought some.

[rlux4]

Darsella, you're just the person I was going to call on! Dave has said his car has only one ground attached to the intake plenum for the injectors. Normally there are two. Did that get changed for the 85-1/2? Does your car have one or two of the grounds on the rear of the plenum?
Thanks,
Ron

[So Cal Mark]

if the regulator leaks, fuel is pulled directly into the manifold via the vacuum hose. You shouldn't have any fuel in the vacuum hose. You can disconnect the vacuum hose and run it to test.

[Darsella1]

Darsella, you're just the person I was going to call on! Dave has said his car has only one ground attached to the intake plenum for the injectors. Normally there are two. Did that get changed for the 85-1/2? Does your car have one or two of the grounds on the rear of the plenum?
Thanks,
Ron

Hello, Darsella's fiance here (she's crashed out)...I'm no expert on these cars, but if you're looking at what I think you are, then It's definitely got two; hope this helps:

[So Cal Mark]

I'd check the ground circuits at the ecu with an ohmmeter and see if they all are connected to chassis ground

[rlux4]

Thank you Darsella's fiance. Those are the grounds we were looking for. So, Dave, you'll need to look for the other ground wire and get it back in place. It's pretty much got to be there somewhere. I'd look between the back of the engine and the firewall for it. Each of those two grounds are for two of the injectors. If it's dangling it may be making intermittent contact with metal and giving you an unreliable ground for those two injectors.
Ron

[Daveje]

Well,I feel stupid the ground was right there on the bolt next to the other one right where Ray's? photo shows. So thanks to Ron for insisting it was there,and thanks Ray. It's now all shiny clean.
I did take another look at the regulator,I think it's OK with no fuel coming thru the vacuum hose. I removed the Cold start valve and tested it,it's getting the voltage but now there is no fuel spray. I know it was working so I guess it has become clogged since Sunday. There is a "click"and there is fuel pressure. I'll try and clean it out but at least this would explain the fact that the car is totally not starting now.
I have checked all the grounds and ohms on the ecu' Mark.All checked out OK. I've also tested the double relay voltages etc. I'll go back and look at these again if the coolant sensor I'm getting doesn't solve my problem.

[Snoopy]

Hi
I have exactly the same problem ! Any news about it ? Coolant sensor ?

[So Cal Mark]

if your cold start inj has become plugged, what are the odds that the other injs are plugged? How old is the fuel? Have you been cleaning the injs on the car or off?

[Daveje]

Well, I just wanted to come back and finish out this thread. The car is running, and not only that it's running excellent. Took it out and drove it for a few miles,topped off the gas,no hesistation,running real smooth.
The reason the cold start valve wasn't working is because once again I had no fuel to the fuel rail. Even though I had previously flushed the tank, changed the pump & filter,pulled the fuel rail and flushed it and the injectors. After that I did have pressure but apparently the fuel system became clogged again in the one place I didn't flush, the metal lines between the fuel filter and fuel rail. Reason being my air compressor was out on loan at the time. Anyway,after flushing the metal lines,re-flushing the fuel rail,gas tank(on the car this time)and new fuel filter and installing the new coolant sensor the car started right up and has been running great since.
I'm not sure what the coolant sensor had to do with it at this point since I changed it at the same time ,Snoopy.I was thinking it was possible the sensor was good all along and it helped when I disconnected because that gave the car the extra fuel It needed,don't know though. I did test both old and new sensors off the car and the new one definitely reacts quicker to temp. changes so it's an improvement. If I get a chance I can put the old one back on and see what happens.
Thanks for the help everybody,I've learned alot about the car in the last 2 weeks if anything.Great site and I'll probably be checking it out just about every day now.

[So Cal Mark]

thanks for the update and congrats on getting the car running well. Perserverence pays off

[rlux4]

Very good news. Thanks for the update, and good job hanging in there. Going through something like this is the best way to learn about our cars.
Ron

[Snoopy]

I will try a new sensor today. Yesterday i try to test the sensor and sometimes it seems not working in the right way...
So engine starts and runs and after some tests its starting short and then stops...

[Daveje]

Good luck Snoopy. My sensor didn't seem right either but it turns out it was OK. I was probably testing it wrong.
Don't get caught in the trap of replacing a bunch of expensive part if you're not sure. Make sure you have good fuel delivery right up through the injectors and good spark before anything else.
If I were you I'd start a thread on here if the coolant sensor doesn't work for you.