My daughter's 92 gxe (VG30E) started running rough last week, so I brought it home from college and took a look at it.

1. Replaced plugs, wires, rotor and cap.
2. Replaced fuel filter

Still ran rough - if it had a carb, I would say it was flooding

3. Replaced engine coolant temp. sensor
4. Replaced O2 sensor

Ran much better - still a miss while idling. Narrowed down to Cyl#4 by pulling plug wires.

5. Checked injectors - 2, 4 and 6 were all over 50 Ohms, 1, 3, and 5 were all between 12 and 13 ohms (1, 3, and 5 had been replaced approximately 2 yrs ago)

6. Replaced injector #'s 2, 4 and 6. I could only get two new injectors from NAPA on short notice, so one of the injectors was a remanufactured injector. (Also from NAPA) The remanufactured injector went into #2, and the new ones went into #'s 4 and 6.

Engine ran like a new one for about 10 min, then started running rough again. I noticed fuel pouring into the exhaust manifold for #6.

7. Tore everything down again and discovered that the #6 injector was pouring fuel. Called parts guy, he got me another injector (New one again).

8. Installed new injector in #6.

Engine ran great, but developed a miss at idle when it got hot. Narrowed down to #2 by pulling plug wires.

9. Ruled out plug, wire, distributor cap.

9. Compression check. All 6 were 178-182 psi.

10. Checked #2 injector - 12.6 ohms at injector and sub harness connector

I am now out of ideas. What about the possibility that the injector in #2 (the remanufactured injector) is failing when it gets hot? The miss at idle only appears once the engine is warm, and is not apparent at rpms above 1000.

Am I going to have to pull the intake for the third time?

Any suggestions appreciated.

 

damn, you've done a lot of work on it so don't give up...after you sort this out it will be good for a very long time...I would guess water temp sensor but you said you changed that fuel pressure reg?(seems unlikely though)...may be bad plug wire? try swapping around and see if the mis goes around...best of luck...

 

would there be vacuum leaks or some sort

maybe cracked vacuum lines or something

not sure what to tell you man im a VE guy

 

I forgot to mention in the original post that I checked the fuel pressure and regulator - pressure was 36 at idle, 42.5 with throttle open. I pressure tested the regulator and it began bypassing at 43 psi, just like it is supposed to.

 

Try cleaning / playing with the MAF plug...After all you've done it's worth a shot.

 

I am going to look at that possibility tonight. I don't think a vacuum leak would be specific to one cylinder would it?

 

My guess would be the #2 injector is no good....

 

Will do tonight!

 

I'm afraid that's the direction I'm headed unless someone comes up with a solution...... I am really not looking forward to pulling the intake again, but I am pretty good at it now.

 

Pull the plug, if it gets worse you can cross that off your list, if it stays the same, you know what the problem is!

 

Make sure your plugs are good and not crossed.

 

Definantly stay far away from reman. injectors...They have a 50% or higher failure rate....

 

If he knows how to do everything he has done already, I'm sure he wouldn't make a 'tard mistake like that.

 

Plugs are new. Not crossed. (I checked to make sure) To test plugs and wires, I swapped plugs and wires from #4(not missing) to #2(missing). The plug and wire that were in #2 when it was missing did not cause #4 to miss. The plug and wire that were in #4 when it was running fine did not improve #2.

 

you could have a defective reman (not unusual) you could also have bad o'rings on the injectors. All it takes is a nick to f one up.

 

yep,that was my other thought...may be you pinched the o-ring when installing...damn, i feel your pain....

 

Try moving the connector on fuel injector for the suspected cylinder around while the engine is running. My 91 VG had a bad connection on one of them. All I did was remove connecter, clean contacts replace and it ran excellent. They develop lots of corrosion.

 

I tried that last night. Cleaned the connector with electrical corrosion wash and protector (very hard to get to due to its location under the intake). I am going to tear it all back down again tonight and replace the #2 injector with a new one. I am also going to replace all of the o-rings on the injectors and the seals where the injectors meet the intake. Miss in #2 cyl. has now progressed to the point that #2 is dead at all rpm ranges. I will update when finished with the injector replacement.

 

I am having similar situitions here. Recently replaced all 6 injectors which was told to be New (but not Bosch brand). I purchased them for much cheaper price.
After warming up, there are some misses still. The engine is not running as smoothly as expected. Also there are some hand engraved numbers marked on the metal casting of each injector. I am suspecting them to be in fact remanufactured. I am looking into this now.

 

you're not the only one
and you've got mail

 

i had a similar problem, motor got swapped out, not really an option 4 u after doing that much work. good luck though

 

Pressurized the fuel rail after removing upper and lower collector (intake). Gas was pouring out of the #2 injector housing on the fuel rail. Pulled injector out of the rail, and the lower o-ring was indeed pinched. Am putting in new injector seal kits for all injectors tonight. New injector (the reman. will be kept as a spare) will go in #2 hole. Will update tomorrow, but I think I've got this one whipped!

 

Good work!
That is why i prefer to pull the fuel rail when chaning fuel injectors. One reason is it would be rather quick and easy to replace. The other is to check leaking when pressurizing before put everything back.

 

Went back together this morning. Changed the oil before turning engine over. I was afraid of gas in the oil due to the leaking fuel injector. Took a deep breath, turned her over, and she ran like a new one. Yee-Ha!!!! Problem solved! Thanks for all of the suggestions!