m10 issues make a sad chinese delivery man :(

[87' 325]

Alright, I have a m10 thats not feeling so well lately. I deliver in this car for income so any help would be appreciative.

A)-Sometimes when Im driving the car and I hit a rough patch of pavement or bump the car dies like the fuel delivery as ceased. Im not sure which fuel pump to look to replace since the car has 2. After the car dies from hitting the rough pavement if I turn the key back to "off" position and restart the car it works for awhile(2 miles) then it will continue as stated above. It seems to be a domino effect after the first rough patch of pavement. I realize this must be fuel/electrical issue. Im not sure why the restarting the car will allow it to work again although. perhaps a fuel pump relay?

B)-My oil pressure light comes on when the car reaches operating temps but only at idle and will go away after giving just the slightest bit of throttle. I have replaced the oil pressure switch recently because the other one began to leak oil from it. What is a easy way to check the oil pressure manually? I have 10w40 in the car.

C)-Occasionally the cars electric components(headlights,cluster,radio) will intensify after giving it throttle. I suppose there isn't enough electrical current at idle? Bad ground? Also, the battery is good and the alternator works.

D)-The speedometer also comes in and out a lot. If i knock on the cluster like a door it will sometimes pop back to life. Is this the nut on the back of the gauge or something more perhaps?

E- When I first got the car it had water accumulated IN the ecu and have since replaced the ecu with the exact same one. Any idea how the heck water got there?

Most of the work I have done to this car has been suspension replacement. Im not much of a gear head when it comes to engine work although. Im trying to become more savvy at it. I love this car to death and hasn't always been this way. I delivered in this car for a year and half with no issues at all. Thanks in advance for any help.

[MattsBMWs]

Alright, for A: I would have an educated guess that you have a bad fuel pump relay, since I've never heard of a pump loosing power going over a bump. Otherwise I would check your main harness connections like the one by the fuse box and going to the ECU. As for B: Do you hear any rod knocks or thumping from your motor at idle that would indicate a loss of oil pressure? Do you have 200k+ on your motor? You could have a dieing oil pump. Otherwise I would have to say it was electrical. Which leads me to C: you may have bad grounds throughout your system. The Bentley book gives you a list of all the major points. I would at least check the lead from the battery to the frame and the ground point under the dash. Remember in most European cars the ground wires are brown. As for D: that is a very common problem in E30s, you need to pull the cluster and re-solder the joints on the speedo. Lastly E: I have no idea how water got in there, but that would REALLY wreak havoc on all the electronics connected to it. You may have had (or have) a leak in your windshield or in the body drain on the other side of the firewall. Hope this helps.

Good Luck,
Matt

[87' 325]

Alright, for A: I would have an educated guess that you have a bad fuel pump relay, since I've never heard of a pump loosing power going over a bump. Otherwise I would check your main harness connections like the one by the fuse box and going to the ECU. As for B: Do you hear any rod knocks or thumping from your motor at idle that would indicate a loss of oil pressure? Do you have 200k+ on your motor? You could have a dieing oil pump. Otherwise I would have to say it was electrical. Which leads me to C: you may have bad grounds throughout your system. The Bentley book gives you a list of all the major points. I would at least check the lead from the battery to the frame and the ground point under the dash. Remember in most European cars the ground wires are brown. As for D: that is a very common problem in E30s, you need to pull the cluster and re-solder the joints on the speedo. Lastly E: I have no idea how water got in there, but that would REALLY wreak havoc on all the electronics connected to it. You may have had (or have) a leak in your windshield or in the body drain on the other side of the firewall. Hope this helps.

Good Luck,
Matt

First of all I would like to say thanks for at least attempting to help me.....that means just as much as solving the problem to me. The fuel cutoff is the most aggravating considering I cant diagnose it until the car decides to do it. I will order a new fuel pump relay I suppose to rule that out....its only 30 bucks. If it were one of the fuel pumps, in speculation, would it most likely be the in-tank pump or the external pump?

My engine has unknown amount of miles on it considering the odometer stopped at 100,000 miles and believe me its got WAY more than that considering I put 100 miles on it a day working. I dont hear any knocks of any kind that is unusual at least to me. I was going to order the oil pressure,oil temp, and volt meter VDO gauges to have a more precise measurement of what is going on. Does anyone know who sells the 3-gauge pod that fits into the sunglasses tray in the center console? I thought it was Bav but no luck there for a e30. This may seem over the top but I like the idea of having the gauges for accuracy.

Ill also order a bentley.....I keep writing off that I don't need one but CLEARLY I do. Thanks a lot for the reference, I didn't know it had the major grounding points in it.


Lastly, anybody got a m10 for sale with ecu and harness in the mid-atlantic region? Maybe a getrag 240 and driveshaft also?

[MattsBMWs]

Sure man, I try to watch the M10 forum from time to time since most of the attention goes to the M20 and swap forums here. It sounds like you've got a plan, keep at it. Post any updates. I have a parts 318i with a good motor and gearbox, but I'm in CA. I've seen a few pop up on the forums from time to time.

Best of luck, Matt

[peete]

Your water in the ecu could mean rust-thru behind the battery. That also means your battery could be ready to fall into your glove compartment. The battery tray is a common rust area in the 318i.
If your lights brighten when you rev and then they stay bright it sounds like the voltage regulator on the alternator is worn out. It's cheap and easy and the Bentley shows you how. But as stated before check the grounds first.
I'm pulling my engine/trans in a week for a swap. 266k, no leaks, maintenance records back to 15k. I have a local buyer lined up but if that falls through I'll let you know. I go to tidewater on occasion but I have no way of hauling it up there.

[E30QC]

Alright, I have a m10 thats not feeling so well lately. I deliver in this car for income so any help would be appreciative.

A)-Sometimes when Im driving the car and I hit a rough patch of pavement or bump the car dies like the fuel delivery as ceased. Im not sure which fuel pump to look to replace since the car has 2. After the car dies from hitting the rough pavement if I turn the key back to "off" position and restart the car it works for awhile(2 miles) then it will continue as stated above. It seems to be a domino effect after the first rough patch of pavement. I realize this must be fuel/electrical issue. Im not sure why the restarting the car will allow it to work again although. perhaps a fuel pump relay?
I'm thinking a point sensor, like a engine speed sensor or something.. its possible to be a connection in the circuitry, or even a blown cell in the battery, but its' highly likely to be an wiring issue. Try jiggling and wiggling these individual parts you have mentioned to see which one can cut the engine out, i would also, for a start pull the timing sensors and checking for abnormal wear and debris, if its' like a m20 its' magnetic and will have shit caked on it.

B)-My oil pressure light comes on when the car reaches operating temps but only at idle and will go away after giving just the slightest bit of throttle. I have replaced the oil pressure switch recently because the other one began to leak oil from it. What is a easy way to check the oil pressure manually? I have 10w40 in the car.
_You procure yourself an operating manual, and a oil pressure gauge set.
You, then go under engine performance diagrams and pull the specifications for the oil pressure from it. Which reads something like this for example: 20psi at 2500rpm

C)-Occasionally the cars electric components(headlights,cluster,radio) will intensify after giving it throttle. I suppose there isn't enough electrical current at idle? Bad ground? Also, the battery is good and the alternator works.
_Do a proper voltage drop to and from alternator to battery, do a alternating current test with vehicle on, check the alternator belt for tension, verify battery voltage off, then at mid rpm range.

D)-The speedometer also comes in and out a lot. If i knock on the cluster like a door it will sometimes pop back to life. Is this the nut on the back of the gauge or something more perhaps?
_check you sensor, location, and cluster backing.

E- When I first got the car it had water accumulated IN the ecu and have since replaced the ecu with the exact same one. Any idea how the heck water got there?
_flood, firewall, broken windshield, surfing,

Most of the work I have done to this car has been suspension replacement. Im not much of a gear head when it comes to engine work although. Im trying to become more savvy at it. I love this car to death and hasn't always been this way. I delivered in this car for a year and half with no issues at all. Thanks in advance for any help.

[E30QC]

sorry, the battery tray on a m10 car is within the engine compartment?..

[85_318i]

Alright, I have a m10 thats not feeling so well lately. I deliver in this car for income so any help would be appreciative.

A)-Sometimes when Im driving the car and I hit a rough patch of pavement or bump the car dies like the fuel delivery as ceased. Im not sure which fuel pump to look to replace since the car has 2. After the car dies from hitting the rough pavement if I turn the key back to "off" position and restart the car it works for awhile(2 miles) then it will continue as stated above. It seems to be a domino effect after the first rough patch of pavement. I realize this must be fuel/electrical issue. Im not sure why the restarting the car will allow it to work again although. perhaps a fuel pump relay?

With your fuel pump, I mean the in line pump that is not in the tank, look at the wiring coming out of it, My 85 318, had a similar problem because the shock mount was rubbing the coating off the wires and would make it lose connection and thus shutting off my car.
As for all the other stuff I would look at all of your grounds, your bentleys will tell you where all of them are at, clean them up and see how that goes.