Fuel System Question

[Republic]

91 318 with 89 325i drive train

Due to poor performance, I recently pulled my injectors, cleaned them and put them back in. The fruits of my labor were noticed right away. Increased performance, faster reaction time, and smooth acceleration at low RPM's in any gear.

This lasted less than 24 hours.

I was in traffic on the E-way waiting to hit my exit. As soon as I had clearance, I put the pedal down and was on my way. At the end of second gear I felt a significant down play in performance. I shifted to third gear and the heavy engine vibration started. Need help in determining the problem.

Things to note in your diagnosis:
1. Shakes happen when under load and not under load.
2. Compression test came back at 175 for all 6 cylinders
3. Exchanged DME's - no difference
4. Pulling 4th cylinder spark plug wire while car running; does not change performance
5. 4th spark plug is saturated with gas
6. Smell Gas in Oil (Dip and Valve Cover)
7. Exhaust is choppy, indications toward fuel system problem
8. No DME codes

I am thinking it might be clear I just need to rip out the 4th cylinders injector; however, I just wanted to get some feedback in case the replacement does not work.

[E30_fiend]

the injector, even though you cleaned it, may be stuck WIDE open. This would cause the fuel to flow into the cylinder when the spark plug isn't firing. This would explain the fowled plug and the fuel saturation on the plug itself and it would also explain the fuel in the oil.

Hope that helps.


Taylor

[jlevie]

This could be bad ignition wires or a bad distributor cap. If the wires are over 5 years old, replace them.

On the chance that it is the #4 injector, swap it to another cylinder and see if the fault moves with the injector.

[Republic]

Oddly enough, Every issue I have had has been with the 4th cylinder. However, the problem was not the injector.

In taking out the injectors, I took off the valve cover and noticed a chunk of metal near the oil valve in the base of the head. The Rocker Arm associated with the 4th cylinder broke.

Anyone know any good write-ups on putting in a new rocker arm?

[e30wheelman]

Anyone know any good write-ups on putting in a new rocker arm?

buy yourself a bently manual and save your self the trouble of searching for write ups:)

[E30_fiend]

^^^^^^

[AlarmedBread]

Pull the valve cover off and check for a broken rocker?

[SpecM]

-Rocker swaps are easy, you just have to remove the head...

-Hey AlarmedBread, i like your sig. its lolable.

[Republic]

absolutely no help. thanks anyways.

[SpecM]

absolutely no help. thanks anyways.

-Holy crap dude... take the head off, remove the cam pulley, remove rocker shaft with a dowl rod, remove rocker, replace rocker... instalation is the inverse of removal.

[e30wheelman]

absolutely no help. thanks anyways.

dude just help yourself and buy a bently manual. it tells you everything youll ever need to know about taking your car apart...(well almost
;)) and youll be able to understand your car more to help diagnos the problem your self. at times it can be the most valuable tool in your toolbox.