Hey guys, I'm having trouble with my 1991 318is.
Short version:
The engine is turning over but the car won't start. I'm pretty sure the fuel pump may have gone bad. I've pulled the relay and used a jumper wire and still can't hear it turn on. I've checked voltage at pins 30 and 87 and am getting power. I've checked for voltage at the two-pin plug at the fuel pump and am getting power. Did the fuel pump just decide to quit? Are there any other tests I should do before dropping $300 on a new pump?
Long version:
When I bought the car the engine ran fine. The problems were:
1. the gas tank had a small leak that had been fixed with some type of gasket sealer
2. the rear dust shields were rusted, causing parking brake to not work (the spring pins had broken through the dust shield)
3. there was rust on everything under the car
4. the hard brake lines in the rear were super brittle and snapped when I tried to change out the soft lines.
So I fixed all that. I'm building this car to for track use, so that influenced some of my upgrades.
1. New stock gas tank (but reused the fuel pump) and new vent lines.
2. Ditched the parking brake (and dust shields) and added a handbrake for later shenanigans. Plumbed this as a passthrough system, so no dual calipers yet.
3. Replaced the steering links, control arms, control arm brackets, front hubs and bearings, rear axles, rear bearings, both sway bars, and soft brake lines, rotors, and pads. I rebuilt the subframes front and rear along with the rear trailing arms (reinforced and powder coated), rebuilt the diff, rebuilt the struts, rebuilt the stock calipers, and rebuilt the driveshaft (new guibo and center bearing). I upgraded all the bushings and replaced the engine mounts. And I replaced all the heat shields and any rusty nut or bolt under the car. Oh and I put in a new exhaust. I also did a power steering delete. And removed my antenna (not going to use the radio).
4. I replaced all the rear brake hard lines with new lines and fittings and then upgraded to stainless steel soft lines.
While doing all this work the battery was disconnected at both terminals. The car was on jack stands for seven months during this whole process. I didn't do any electrical work other than disconnecting the parking brake and capping the blue parking brake sensor wire. All the other stuff was unplugged and then plugged in again when the car was finished.
After finishing all the work, I charged the battery and turned the key on (not to start, just to ACC to make sure all the lights came on) and when I did that I got a small puff of white smoke from the ignition or somewhere under the dash. We had a lot of rain the day before, and my garage got very wet inside for some reason, so it could have been moisture. But I removed the knee bolster and checked everywhere for a burnt wire. Nothing. I have yet to pull the steering wheel and look at the actual ignition switch, and I have not pulled the dash. But now my radio won't turn on. I was going to pull it at some point, but it's strange it's not turning on. That could be where my short was.
With no sign of burnt wires I turned the key again and could not replicate the smoke. So I went to start the car, and it won't start. I can't hear the fuel pump coming on. I made a jumper and jumped terminals 30 and 87, and still can't hear the pump. I checked and I have voltage at terminals 30 and 87, so they seem to be getting power. I have voltage at the plug at the fuel pump (or sending unit—the one with two prongs). I pulled the fuel pump and have continuity at the red wire and continuity on the black wire on the pump itself. It seems to me that I'm getting power to the fuel pump, but the pump won't kick. It could be a bad pump, but it's strange because it worked fine before I tore the car apart.
Before I spend $300 on a pump, I wanted to get a second opinion. Does that sound right? Power at the relay, power at the plug, but no pump coming on? I'm hoping it's not related to that puff of smoke, which I can't diagnose to save my life. If it is the radio, would the radio's anti-theft be affecting my starting issue?
Thanks for the help, and sorry for the saga.
Short version:
The engine is turning over but the car won't start. I'm pretty sure the fuel pump may have gone bad. I've pulled the relay and used a jumper wire and still can't hear it turn on. I've checked voltage at pins 30 and 87 and am getting power. I've checked for voltage at the two-pin plug at the fuel pump and am getting power. Did the fuel pump just decide to quit? Are there any other tests I should do before dropping $300 on a new pump?
Long version:
When I bought the car the engine ran fine. The problems were:
1. the gas tank had a small leak that had been fixed with some type of gasket sealer
2. the rear dust shields were rusted, causing parking brake to not work (the spring pins had broken through the dust shield)
3. there was rust on everything under the car
4. the hard brake lines in the rear were super brittle and snapped when I tried to change out the soft lines.
So I fixed all that. I'm building this car to for track use, so that influenced some of my upgrades.
1. New stock gas tank (but reused the fuel pump) and new vent lines.
2. Ditched the parking brake (and dust shields) and added a handbrake for later shenanigans. Plumbed this as a passthrough system, so no dual calipers yet.
3. Replaced the steering links, control arms, control arm brackets, front hubs and bearings, rear axles, rear bearings, both sway bars, and soft brake lines, rotors, and pads. I rebuilt the subframes front and rear along with the rear trailing arms (reinforced and powder coated), rebuilt the diff, rebuilt the struts, rebuilt the stock calipers, and rebuilt the driveshaft (new guibo and center bearing). I upgraded all the bushings and replaced the engine mounts. And I replaced all the heat shields and any rusty nut or bolt under the car. Oh and I put in a new exhaust. I also did a power steering delete. And removed my antenna (not going to use the radio).
4. I replaced all the rear brake hard lines with new lines and fittings and then upgraded to stainless steel soft lines.
While doing all this work the battery was disconnected at both terminals. The car was on jack stands for seven months during this whole process. I didn't do any electrical work other than disconnecting the parking brake and capping the blue parking brake sensor wire. All the other stuff was unplugged and then plugged in again when the car was finished.
After finishing all the work, I charged the battery and turned the key on (not to start, just to ACC to make sure all the lights came on) and when I did that I got a small puff of white smoke from the ignition or somewhere under the dash. We had a lot of rain the day before, and my garage got very wet inside for some reason, so it could have been moisture. But I removed the knee bolster and checked everywhere for a burnt wire. Nothing. I have yet to pull the steering wheel and look at the actual ignition switch, and I have not pulled the dash. But now my radio won't turn on. I was going to pull it at some point, but it's strange it's not turning on. That could be where my short was.
With no sign of burnt wires I turned the key again and could not replicate the smoke. So I went to start the car, and it won't start. I can't hear the fuel pump coming on. I made a jumper and jumped terminals 30 and 87, and still can't hear the pump. I checked and I have voltage at terminals 30 and 87, so they seem to be getting power. I have voltage at the plug at the fuel pump (or sending unit—the one with two prongs). I pulled the fuel pump and have continuity at the red wire and continuity on the black wire on the pump itself. It seems to me that I'm getting power to the fuel pump, but the pump won't kick. It could be a bad pump, but it's strange because it worked fine before I tore the car apart.
Before I spend $300 on a pump, I wanted to get a second opinion. Does that sound right? Power at the relay, power at the plug, but no pump coming on? I'm hoping it's not related to that puff of smoke, which I can't diagnose to save my life. If it is the radio, would the radio's anti-theft be affecting my starting issue?
Thanks for the help, and sorry for the saga.
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