1989 Technical Problem...Need Advice

[CaptainBlue]

Hello, I need some advice on a problem. I have a 1989 Convertable with 116K. The car died about 500 yards from the driveway. The vehicle was not cold when it died (I had finished some errands and was on my way some where else) At the time this happened all gages were reading within normal limits. The vehicle would not start, It would turn over but not start. Up to now I have not had a problem with this car. Here is what I have checked.

Fuel: Checked Fuel pump operation (I can hear it), Pulled the fuel line running into the fuel rails (fuel comes out strong), Checked Fuel pressure (at 40psi Steady in all modes- Cranking or ignition on). For good measure I replaced the Fuel pump relay. There is no fuel in the cylinders nor is there a smell of fuel.

Ignition: Checked Coil, Cap, Rotor, Ignition Module, and Pick up coil all good. Have strong Spark.

Electrical: Battery holds a charge, good 12v through out system at various points. Replaced the Oil Pressure Switch, I have 12v at the injectors.

ECM: No codes were set. Checked each pin of the ECM for proper signals and they are all there, TPS (.54), MAS, Power, etc..

VATS: Checked resistance of ignition key against wires from the ignition. It is good.

I have a digital Multimeter and some other test equipment but not an Ociliscope, however I don't believe the injectors are being pulsed by the ECM. I have shot starter fluid into it and it will start and run for as long as I use the fluid. I'm at the point that I'm prepared to replace the ECM but before I do that I would like to get your opinion on what I've done so far and what potentially I've missed.

 

[Ken]

Wow, thorough checks already performed! Nothing else comes to mind for me at this time. However, when I was having a curious dying problem when I was on the road with my '87 back in 2001, we replaced the coil and ignition modules and all that, just as you've already checked, but my problem kept recurring, and it always happened when I was miles from any help.

The final time it happened, I just started feeling around everywhere I could around the plenum and distributor area, and lo and behold it fired up! Turned out to be a broken tab on the battery connector to the distributor. It had dried out and cracked at some time or another, then just worked itself loose at inappropriate times. :eyerole

Check all connectors.

 

[wb9eiltj]

Hi. You can check the resistance of the injectors. Any one of them that is shorted will cause all to not function. If you find one shorted leave connector off that injector only and it should start.

 

[CaptainBlue]

Will do, Thanks

 

[CaptainBlue]

Hi. You can check the resistance of the injectors. Any one of them that is shorted will cause all to not function. If you find one shorted leave connector off that injector only and it should start.

Okay, You nailed it! One injector on the Driver side was shorted. I left the plug off and it fired right up. I plugged it back in for good measure to ensure it was the issue and the problem came back so it is diffenately the one injector. I appreciate the help. I had not thought of checking the resistance on the injectors because I didn't believe that one going bad would cause a failure of the all of the others. I also want to thank everyone else who responded. Thanks

 

[Moonunit 451]

WOW! Now that's what I call RESULTS, and qiuck too. Great job wb9eiltj! And welcome to you both

 

[CaptainBlue]

WOW! Now that's what I call RESULTS, and qiuck too. Great job wb9eiltj! And welcome to you both

I had never been on a forum before but after wrestling with this problem for about a week or so I wanted to talk with other owners to see what thier experiences had been.

Do you recommend replacing all the injectors or simply the one that failed. I'm leaning toward all of them considering the age of the car.

Thoughts?

 

[Vettefan87]

You can just replace the one injector without running into any other problems. Some people here on the forum have sent there injectors out to get rebuilt, I am not sure where though.


Justin

 

[Moonunit 451]

If you can afford it, it might not be a bad idea to replace them all at them all at the same time. If you do, get the FMS injectors (Ford).

 

[G Winter]

moonunit.
Why the FMS ?

 

[Ken]

Cost.

 

[CaptainBlue]

Cost.

Thanks for all the info. I will likely replace all.

Thanks again for all the help

 

[vetteboy86]

Okay just to clarify, one injector bieng bad will cause a no start condition?Now you used an ohm meter to check the resistance. Is that the only way they fail if they do? The spray pattern can be incorrect, or the flow rate be off right? Also what actually makes them short out? I guess the computer must detect the change in current within the injector circuit and prevent the car from starting.

Just some facts I would like to know.

Thanks all
Craig

 

[wb9eiltj]

Hello, If only one injector is shorted,only on the early TPI engines,all of the injectors will not work because they are wired in parallel. The one with the short will put such a large load on the pulse signal that there is no signal left to fire the others. As a retired corvette mech. I've seen many vettes with this prob. It seems that in the past couple years this has become a more common prob. with the RFG gas. The inner seal breaks down letting gas into the injectors solenoid and shorting it out.