Fuel Injector/misfire troubleshooting

[Chemist7GST]

I have a 1998 GST and I am having issues with my 2nd fuel injector. When I "cold start" the car, it will run fine no matter how long I run the car. However, if I drive a short distance and turn the car off,the 2nd injector will cease to work . I have had all injectors cleaned as of this past Monday and installed them back on the car. Same problem with the same injector after the cleaning. When the car is running on the initial start up, the injector responds to having the clip pulled from it. Once I restart it after running it doesn't respond to having the clip pulled and the car is basically running on 3 cylinders at that point.

All cylinders, including the 2nd one are receiving spark. I did do a CEL code check and it said "misfire". I'll get he exact code again and let you know.

Any help would be much appreciated as this issue is becoming very annoying to say the least.

 

[gofer]

You just need to keep your car running if your making quick stops somewhere, then just let it sit for awhile if you want to shut if off...

When you "cleaned" your injectors did you actually get them taken out and cleaned by an injector shop or did you dump a jug of injector cleaner in the gas tank? Fuel Injector Clinic (FIC) can clean them for $20 an injector, heres a link to their website. FIC clean/flow testing injectors

If you did get them cleaned and not just ran cleaner through your fuel tank then I suggest moving that injector from #2. Make sure its the injector first and not the wiring going to it, see if the car does the same thing when another injector is in the #2 spot. If the misfire moves to a different cylinder when you move injectors then you know its a problem with that injector.

Looking at your mods list in your profile it appears that your still running the OEM 450cc injectors? If you eventually plan on running a bigger turbo and turning up the boost this could be your calling to get bigger injectors. Along with it though your going to need something to control fuel, just plan on budgeting that in with the cost of the new injectors.

 

[Chemist7GST]

I sent them TLF Performance parts and had them all cleaned on the machine. I will try switching them around to see if its the plug going to the injector.

 

[hhuricane]

Could be an injector driver in the ecm on its way out. Pull it and check for the dreaded leaking caps.

 

[gofer]

If the problem stays at the #2 injector I wouldn't even dig into your center console and look at your ECU just yet, pull out a digital multimeter (DMM) and test the resistor pack thats attached to the firewall.
The link below shows the location of the connector thats coming off the resistor pack and also what the connector looks like after you unplug it.

Fuel Injector Resistor Box

Heres how to test it.

 

[Chemist7GST]

If the problem stays at the #2 injector I wouldn't even dig into your center console and look at your ECU just yet, pull out a digital multimeter (DMM) and test the resistor pack thats attached to the firewall.
The link below shows the location of the connector thats coming off the resistor pack and also what the connector looks like after you unplug it.

Fuel Injector Resistor Box

Heres how to test it.

Preciate the help. Me and a buddy of mine are gonna check this after work today. I'll let you know by tonight or tomorrow what we find out

When checking the resistors, does the ignition need to be set to on for it to get a reading? We got some readings initially then they stopped. 1-3 was in the listed range. The others however were in the 8.0 to 9 range. Then it stopped sending a signal.

 

[gofer]

Did you fix the issue?