Yet another 'It Won't Start' post -- need help

[kristoj]

I have an '82 FI Turbo Spider that had been running fine, now it turns over but without so much as a sputter. I searched prior posts and have tried the following based on those posts:

1) I changed the inline fuse (brown wire) behind the fuse box. The old one fell apart when I took it out to check.

2) I removed a spark plug and checked for spark -- it has excellent spark

3) I pushed open the AFM flap with the ingition on -- the fuel pump kicks on loud and clear

4) I removed the three relays under the dash, cleaned the terminals and tapped on them and reinstalled

The car still doesn't even sputter. It does smell like fuel when it's turning over, but the plug was not wet when I took it out to check for spark. Is it possible the injectors are not firing, and if so, how do I check that and what are the probable causes? Any other ideas are welcome!

Thanks guys.

[rlux4]

When you're cranking it do the gauges come up? The fuel gauge will be the most noticeable. I don't mean the dash lights. If your gauges don't get power it may be the ignition switch, or the wires coming out of the back of it to the white connector. 2nd thing I'd try is leave the duel relay down where you can get to it and tap it while you're cranking. My old one would periodically cut out before I replaced it and it would kick in after a couple of taps to wake it up.
These are things I had trouble with in the past. Things like sensors, AFM, cold start valve, ect. won't stop it from starting, only cause it to run poorly. So it's got to be a power or control issue.
Do you have Brad Artigue's FI troubleshooting guide?
Ron

[kristoj]

Thanks Ron. The gauges come up when I turn the ignition key. I have Brad's FI guide open on the computer as I type. I will read through it tonight and attack it tomorrow. Does anyone know how to check the double relay? I am not electrical wiz, but I do have a multimeter.

[kristoj]

Well, I let the double relay hang down while I turned over the engine and I could feel it click each time I attempted to start the car. Still no luck...

[kristoj]

Update -- car is running! Unfortunately, I don't know what I did. I unplugged one of the injectors to put a test light on the connector. I did see a very weak or dim pulsing light when the car was turning over, but it would not start. Next, I unplugged the connector on the cold start injector and put a test light on it. When the car turned over the light came on noticably brighter than the other injector, and the car fired up. It idled very roughly at first and my wife said there was smoke at start up at the back of the car (just not enough for me to see from where I was sitting so I don't know if it was black, blue etc). But she did say it smelled like fuel. I then turned the car off, plugged in the cold start injector connector, and the car again started normally and ran fine.

So while I am glad the car is running, I am very concerned that I don't know what caused the problem. I obviously don't want to get stranded again with another $70 tow bill -- though my six year old son thought it was the coolest experience ever. Any ideas???

[rlux4]

The signal to the injectors comes from the ECU. It is extremely rare for one of these to go bad, so as Mike B. would say, start with the simple. I'd pull and test the injectors. Simple enough, pull one at a time, point it into a container and crank the engine. It should pulse a nice spray, not a stream. I'm thinking now that the fuel smell your getting is from the cold start vave. The fuel is under pressure and makes a circuit from the tank and back. That pressure forces fuel out an injector when it gets the signal to open from the ECU. If one or more of the injectors aren't opening, it may not be getting enough fuel for combustion.
It sounds like your are getting spark, so it must be fuel. The third part of the equation (timing) doesn't appear to be a factor.
Good luck,
Ron

[kristoj]

Ron,

Thanks for your ideas. I think I have the problem resolved. It doesn't want to start with the cold start injector plugged in. So I drove th car around town to get it good and hot (ran beautifully). Then I connected a multi-meter to the cold start injector connector and cranked the engine. It showed a spike in voltage for about two seconds. The cold start injector should not be getting any voltage when the car is hot. Therefore (I think), it must be the thermo time switch, which tells the ECU whether or not to turn on the cold start injector based on the temperature of the engine. So my theory is that is was turning on the cold start injector every time I tried to start the car and flooding the engine. The car is starting fine now that I unplugged the cold start injector.

So I will order a new thermo time switch and go from there. It runs $60 at International Auto compared to $400 for a rebuilt ECU -- always start with the cheapest part first!

BTW, I know that the injectors are good because I sent them out to be cleaned/tested over the winter while I had my whole car apart and they all checked out fin after the cleaning. I have only put a little over 100 miles on the car since, so it is unlikely they would have gotten mucked up since then. I also changed the fuel pressure regulator, fuel hoses and upper and lower injector seals.

[rlux4]

Makes sense to me John, I think you got a handle on it. Anyway, we're not going to need a cold start valve for about 7 more months!
Ron

[kristoj]

Like I said, my six year old had a ball riding home in the tow truck yesterday. And now he thinks I'm a hero for "fixing" the car this morning. I didn't have the heart to tell him that I have no idea what I am doing and that I got the car started by accident when I randomly unplugged the cold start injector!

[rlux4]

You know, sometimes I think there is a 6th sense, or subconscious element at work when we accidently fix a problem. I've had my car stop and for some reason or other I try something and bingo, it's "accidently" fixed.
Ron

[kristoj]

Just to close out this string for future reference, the problem was in fact the thermo time switch. I changed it last night and the car now starts and runs great hot or cold.