85 318i Issues

[Hey_You]

Right now the poor ole' M10 is having an intermittent misfire under load, and slight erratic idle at times (never above 1200, but will drop to about 500 or sometimes die) I have replaced all the usual suspects (plugs, wires, cap, rotor, fuel filter) and have cleaned my IAC valve. I do have a little oil going into the spark plug tubes but it's not making it past the threads of the plug. I have done some reading and from what I can make of it it could be the Alternator or fuel pump or coolant temp sensor. Most of the time when it misfires it just loses most power for that split second, but other times (such as today) it will feel like a complete fuel cut for a good second or two which is why I suspect the fuel pump. Any other ideas or recommendations to check before I start buying these more expensive items? Thanks

[Jaxx_]

before you go chasing your tail, what were the plugs gapped at when you put them in?

What did the old plugs look like? super black? white like casper the ghost?

[Hey_You]

The first set I put in came out with #2 cylinder oily and black, the other 3 were the usual greyish color. I then replaced the cables with Bimmerworld 8mm cables (I WOULD NEVER BUY THESE AGAIN! Corroded and failed within 2K miles) and replaced those with a factory set of Bosch wires, then replaced the plugs again just for reassurance (which were still good) with Bosch Platinum +2 (non gapable). Just a couple hours ago I was driving and my car would have the long stall again, it died on me twice at an intersection and was difficult to restart. Not too sure if it makes a difference but my temperature gauge is fairly erratic and my fuel mileage gauge goes berzerk (fuel gauge only when misfire episodes occur)

[Hey_You]

So cruising down the freeway at 80 mph (SoCal...it's normal) my fuel completely would cut out for about 5 seconds leaving me powerless and coasting on the freeway until it would pick back up and it did this to me about 4 times within about 5 miles. I don't smell fuel so no leaks that I am aware of allowing air into my system to create a hiccup like that, so I ordered a new fuel pump as I have already replaced the filter. Lets just hope I chose to replace the right one (inline) or both my pumps will be new and shiney. I'll update around Friday when my new pump comes in (then I'll go ahead and rebuild my shifter while I'm under there too since I have the replacement parts for that)

[Farbin Kaiber]

Get rid of the Bosch Platinums. Your car should be using the usual copper core Bosch WR9DC+'s. The older BMW's do not fare well with newer platinum style plugs.

Also, Get a Bentley Manual, and spec out each sensor in the fuel system. I would also verify condition of the Coolant Temp sensors.

(I went through ~1200 worth of parts trying to fix an 84 318i running issue, finally yanked the engine with intent to 24v the car...)

[a3ternus]

I ve been using standard Bosch WR8DC for the
last 7 years and no problems at all.
Also I d check my fuel pump.
N.

[Hey_You]

It's been awhile, but I did replace my in-line fuel pump, and it helped out a ton! I did notice that my fuel lines are cracked a little, so I'm going to start replacing those. Also, some vacuum hoses are cracked which means...those need to be replaced too, the never ending saga. It every so often has the misfire, so I guess I'll be replacing my plugs with OE. However, when it starts missing while cruising, if I stop in a parking lot, turn it off for about 2 minutes, then restart my car, boom, problem gone. One day it wouldn't rev past 5500 though, so that caught my concern, and sometimes my gauges stop working (all buy my speedo), does that mean my cluster is going out or should I be chasing down a power supply problem?

[Hey_You]

So the cluster problem turned out to be a problem with the fuse, turns out it was just a little loose. Went out this morning to start my car and let it warm up a little, and noticed the bronze bomber is bleeding to death. Looks like the oil leak is coming from the rear of the engine at the bellhousing. Possible rear main seal failure I think. Any other possibilities you can think of?

[Javier h]

A few things. Always use the stock plugs on these cars. Whatever came original from the factory. I've heard horror stories about platinum on E30s and at the end everyone recommends the oem stuff especially on an M10.

Second, I was going to suggest a lose wire, especially if that car has been in an accident (start there when inspecting an lose wires). I had similar issues on my 84 318 after I repaired my car from a fender bender but it seems as if you figured that one out.

I thought the engine shutting down was a relay (fuel relay? its literally right there where all the fuses are) but your symptoms sound different. You might want to to take it a good BMW place on your next oil change. Here in the valley there are a few good places, some of which are recommended. I'm thinking Castro's although I have never been there personally. These things are sometimes hard to diagnosis. At the end, I had hesitation problems on my 84 318i ....but it was totalled on the freeway a decade ago during a rain storm. Never did figure it out. Good luck.

[Hey_You]

I ended up buying a set of stock plugs a couple weeks ago, just haven't installed them yet because I don't have a gapper at this house, it's up at my parents, so I'm gonna wait until I go up there. The oil leak that I thought was my rear main...well...it wasn't. I'm ashamed to say that I didn't tighten my oil filter enough when I installed it...LAST MONTH. My guess is the ole' M10 vibrated it loose. Good firm twist and I was back in action, no major leak (just the regular ones, doh!)

[a3ternus]

A few things. Always use the stock plugs on these cars. Whatever came original from the factory. I've heard horror stories about platinum on E30s and at the end everyone recommends the oem stuff especially on an M10.

I know that from experience,too.
I was using Champion spark plugs and the Exhaust manifold (an Alpina one) was melting/damaging them one by one during a period of a year...
N.

[Hey_You]

Update...new copper plugs installed, also replaced my distributor cap since it was showing some major signs of wear due to the mistake I made installing it the first time...(another ashamed moment) Still had the intermittent missfire. So today I decided to go ahead and replace my coolant temp. sensor, and so far, all is good. Actually seems like it smoothed things out for the most part. Hopefully that took care of the problem. The other sensor that is connected to the coolant temp gauge...what's the name for that? And where can I get the replacement wire ends to connect to it?

Later that day: Still missfires, so that didn't solve the problem. Could it be a fuel pump issue? Every time it starts running that way, the MPG gauge swings past 40 and then back down to where it should be. Any other things I should check?

[Hey_You]

Could the angle of the exhaust have an effect on how the engine runs? I mean by built up backpressure, or possible valves needing adjustment where the exhaust is going back into the cylinder? I have been driving my car for 2 days straight after fixing my exhaust hanger and so far, no terrible missfire like it has been having.

[KenC]

1. Gap the plugs to .35-.40 (they're .30 out of the box).

2. The symptoms sound similar to when the fuel pressure regulator crapped out on my old M10.

[Hey_You]

Thanks, I'll double check my gap tomorrow, as I gapped them to what the parts store person recommended, but I don't recall what they are at. Any way to test the FPR?