Bad injector symptoms
Bad injector symptoms After my AFR 180 and LE cam swap my car just doesnt run as strong as it should. You can also feel its stumbling 1000-2500 rpms while cruising. Also surges/jumpy 1000-2000RPM. WOT it feels pretty good, no hard missing and you cant feel the low RPM miss. Trying to figure out whats going on. Send the datalog to pcmforless for a tune touch up and he didnt really see anything wrong with it.
Every part on this build is pretty much new. Only things i didnt put on new were coil icm and injectors. My buddy had 30# red tops lying around so thats what i used and tuned for. Im questioning these injectors since i dont know where they came from or why they were given to him. Wouldnt injector not firing or not working properly pop up on o2s datalogging? or am i off?
Basically what im trying to say is what do bad injectors do? Testing them damn near costs what i could get more used ones for. I dont want to just buy injectors and throw em on like thats the problem cause it very well could be something else, im just out of ideas in my own head.
Thanks guys
Every part on this build is pretty much new. Only things i didnt put on new were coil icm and injectors. My buddy had 30# red tops lying around so thats what i used and tuned for. Im questioning these injectors since i dont know where they came from or why they were given to him. Wouldnt injector not firing or not working properly pop up on o2s datalogging? or am i off?
Basically what im trying to say is what do bad injectors do? Testing them damn near costs what i could get more used ones for. I dont want to just buy injectors and throw em on like thats the problem cause it very well could be something else, im just out of ideas in my own head.
Thanks guys
Use an automotive stethoscope, place the probe end on the body of the injector and listen for a tell-tail "Tick-Tick-Tick" at idle. Compare the sound of all eight injectors, if one is "off" from the others, you'll be able to hear it in either the frequency or strength of the "Ticks".
Keep in mind, if an injector does not "Tick" - it could be an electrical issue; temporarily switch electrical connectors with the adjacent injector, if the "issue" moves cylinders, then it's an electrical issue NOT mechanical.
Good Luck.
Keep in mind, if an injector does not "Tick" - it could be an electrical issue; temporarily switch electrical connectors with the adjacent injector, if the "issue" moves cylinders, then it's an electrical issue NOT mechanical.
Good Luck.
damn. you know more than i do. i just told pcmforless i got the 30# ford red tops. Does he need more info?
Im probably running a compression test this weekend as well. i gotta get this thing figured out
Im probably running a compression test this weekend as well. i gotta get this thing figured out
- With the engine running at idle, gently grab the wiring harness above each injector and wiggle the wires around. If the engine stumbles, you've found either a poor or a intermittent connection.
- With the engine running at idle, pull off each injector clip, one at at time, then reconnect. If the idle quality stumbles, then that injector is good. If the idle quality isn't affected, then likely you have a bad injector/wiring harness.
- Get a bright LED, solder the appropriate resistor to it for 12v. Solder some 10" or so of wires to the legs of the LED. Place the wires in some shrinkwrap or somesuch to keep the wires tidy and out of the way. Once again, with the engine idling, pull off each injectors clip and put the positive of the LED on the Positive clip of the injector connector and negative on the negative connector. The LED should blink rhythmically. If it doesn't blink at all or erratically, then you have a suspect wire. Replace the clip on that injector and move to the next one and repeat. I found my bad wiring harness on #2 this way.
- A truly bad injector is difficult for the shadetree to determine w/o the proper tools. I bought a device that is pistol shaped with a pointed awl like end. While the engine is running, you press the pointed end against the body of the injector. If the injector is firing , then the tool both lights up(internal LED) and it chirps. You repeat this for each injector. The tool was about $90.00 if memory serves.
