Ok, so I am driving home the other night and just as I pull in to park, out of nowhere my 130,000 mile VG starts to miss fairly bad. I park, noticing that in park the miss is very noticible. Let it sit over night, thinking I may just wake up and it will have fixed itself. Heres my question, i started looking at things.. disconnected the plug wires one at a time to try to determine what cylinder is causing the trouble, the front middle one (not sure of the # at the moment) made very little if no difference in the way the engine ran when I disconnected it. So, assuming its a fuel delivery problem to that cylinder as there was good spark, would it be safe to assume an injector took a crap?? or is there something else I should look for. Also, when an injector goes bad would it be common for it to set a code in the computer? my check engine light has not come on. Thirdly, will driving it with this condition cause any damage?? do injectors typically run lean or rich when they go bad? if its lean, would removing the spark plug wire from that cylinder prevent any engine damage that could happen to that cylinder due to the mixture being too lean?? i know this is a pile of questions, hope someone can make sense of what I have typed :-D thanks all

 

I would chang the plugs/wires first...If it still persists...Then an injector would be suspect...

 

I have around the same mileage as you and the same thing happened to me one day, I was running on 5 cylinders, but it ended up fixing itself the next day or so. Maybe some injector cleaner would help you out temporarily, or hopefully it'll just fix itself like mind did.

It's weird that your CEL didn't come on though, because mine did. Bad sensor maybe?

 

i was hoping it would just fix itself, ironically this happend 340 miles after I put in some injector cleaner.. i was thinking that maybe had something to do with it, perhaps loosened something enough that it clogged the injector.

 

definatley change out the plug and wire first. If you discoed the spark plug wire and the engine ran the same, it could be that the plug is bad. How did you know that you had good spark? Anyway replace the plug then the wire, and then the injector. Remember do the cheaprest first. I know the plug wires come in a set, so steal one off someone elses car if the problem persists after you replace the plug. (jsut for troubleshooting purposes) Relace the spark plug even if it looks good. trust me

 

well, as for the spark I just disconnected it and used the old screwdriver to block method of testing for spark, had a good strong spark equavilant to the other cylinders.. i know, i know.. thats not the best way to test it, but it works :-) I'll probably just replace the cap, rotor and plugs as I know they are all due anyhow and take it from there... i just hate to assume an easy fix, im kind of a pessismist when it comes to fixin my Max... always hope for the best, but expect the worst lol

 

it's your injector, don't even mess with the distributor, or buying wires/plugs. you're getting a spark, so if anything, before you dig in to replace the injector, swap a wire with another clylinder to make sure it's not just that wire shorting out. if you have a compression guage then it's worth it to check the compression. don't worry though, it's unlikely it'll be shot.

 

I suggest that you pull codes from your ECU first, it is known that the check engine light for our cars will not come on even though some codes is being registered by the ECU. I had the hesitation problem before and the car literally felt like it was about to shut off on me, turns out I had a bad O2 sensor.

 

I'll definitely take all the advice into consideration, i am planning on replacing the cap/rotor/wires/plugs no matter what as they are due anyhow.. I also noticed today (its cold here) that my heat isnt blowing hot even though i had it set to 80 and my engine temp is up where it should be... more and more strange stuff just keeps popping up lol

 

OK, after reading a lot of posts on here about similiar problems I thought.. hmmmm... wonder about the CTS.. so I went out to my car, simply wiggled the connector on the CTS and guess what.. fans kicked on, stayed on.. engine runs like a top other than the fact that it is idling at about 1500 RPM. drove it a little bit and I think it actually runs better than it ever has before. Now, the question is this. My radiator fans stay on all the time, idle is high.. so, I assume its caused some sort of default/closed loop by wiggling the connector that must be coroded or perhaps the wires to it are bad??? does this put the entire ecu into a closed loop or just the CTS related items and how will this affect performance, drivablilty and economy? Yes, I plan on replacing it and sorting out any wiring issues that may accompany it but I wont have the time to do that for a few days and just would like to know the short term effects by using it this way. thanks again everyone for all your advice and replies

 

I had a similar problem and found a fuel injector was bad but no ECU codes other than 55 (good). I replaced the bad injector and it ran okay for a year or so. The problem started again and this time the ECU code read Injector circuit and two other injectors had high resistance. For my VG30DE engine I got a pair of injectors for 10 clams each at of junkyard with a sr20 motor. I'm not an auto mechanic but I think the electro-coil in the injector is prone to overheating when the needle gets gummed up with fuel. The wire in the electro-coil is very small, about 200 microns in diameter.

 

when you turn the key to "on" the other lights and cel light up to let you know the bulbs are good

 

I am also having a similar issue but my CEL did come on.

I tried the wire test and found my front middle (i think #2) wire has no effect on the rough condition of the engine.

Also (n00b question incoming) my fans only come on after i disconnect one of the spark plugs lol they arent on the whole time the engine is running, are they supposed to?

I am running some injector cleaner, i believe that one of the injectors was replaced back before i bought the car a bit over a year ago.

Ill try replacing the plugs first.

Are the injectors pretty easy to replace?

Any info would be appriciated.

p.s.
The spark plug wires do carry quite the charge lol didnt hurt that bad...

 

Awesome so 2 days ago i had to run my brother somewhere and random my CEL turned off and my car went back to idling like a champ

Sadly about 2 days later i discovered a coolant leak from a hole in a radiator hose.

Cars are Awesome