E30 starting? Problem

[claye30]

Hello all. I picked up a 89 vert a few days ago as a project. I've been diagnosing it's no start condition and have made some progress but im stuck. I have spark for sure, I tested with the spark plug wires. The car will crank and turn over but then immediately dies. I'm about 90 percent sure it's fuel related. The fuel pump does NOT get power from the fuel pump relay, I tested the connection. I hard wired the fuel pump to a spare battery, and it turned on. Shortly after, the car fired and drove for about 30 mins. I turned it off and 10-15 minutes later, the same problem is occurring. car starts but immediately dies and sputters out. I tried to jump the fuel pump relay with a wire, but it didn't turn on the fuel pump. Using my multimeter, the fuel pump relay pins 30 and 87 didn't have any voltage flowing through them. I pulled the main relay, and it's pins didnt seem to have volatge either, but wouldn't this prevent the car lights from turning on and cranking? What should I look at next if the relays aren't even getting power? battery connections, ecu? Any help would be appreciated, i'm not sure where to start my troubleshooting. Thanks so much.

Okay guys, should hopefully be my last update on my quest to get my project e30 driving. I ran many many diagnostic tests in the last couple of days to try and rule out possible faulty wiring/relays. I took out the ECU and pin tested everything. My injectors get power, my fuel pump gets power, my fuel pump and main relay get power and audibly click. (I got new relays.) All my main grounds are good. I can crank and the car will start for a couple seconds then die. I assume it is fuel pressure as I can use starting fluid to get the car to run! But when I apply throttle it falls off and dies. I want to say i've narrowed down the issue to either my fuel pump being weak and not supplying enough pressure, or some issue with the injectors, even though I know they are getting power and clicking. I think I am going to get a fuel pressure gauge and hook it up to the return line of the FPR to see if the pump supplies adequate pressure. Is there something else it could be? (Side note, the fuel pump still does not prime when the key is on the second position, and there is not voltage at the wires unless the car is cranking, where it gets 11 ish volts.) Thanks guys.

[It's Soda Not Pop]

Okay guys, should hopefully be my last update on my quest to get my project e30 driving. I ran many many diagnostic tests in the last couple of days to try and rule out possible faulty wiring/relays. I took out the ECU and pin tested everything. My injectors get power, my fuel pump gets power, my fuel pump and main relay get power and audibly click. (I got new relays.) All my main grounds are good. I can crank and the car will start for a couple seconds then die. I assume it is fuel pressure as I can use starting fluid to get the car to run! But when I apply throttle it falls off and dies. I want to say i've narrowed down the issue to either my fuel pump being weak and not supplying enough pressure, or some issue with the injectors, even though I know they are getting power and clicking. I think I am going to get a fuel pressure gauge and hook it up to the return line of the FPR to see if the pump supplies adequate pressure. Is there something else it could be? (Side note, the fuel pump still does not prime when the key is on the second position, and there is not voltage at the wires unless the car is cranking, where it gets 11 ish volts.) Thanks guys.

The fuel pump doesn't prime on M20 E30's. The DME has to see timing from the CPS before the pump turns on. It could be your FPR. How old is your fuel pump? is the original one? How old are most of the sensors and parts? Sometimes it's a good idea to replace all wear items in a car that's 30+ years old and you know that you've never replaced them.

[MrBurgundy]

You have to rig up a fuel pressure gauge to the line and make sure you're getting fuel at the rail.

You could even just loosen the line to the rail and crank it and see if you see pressure shooting out. If you do and there still seems to be a fuel problem, I'd check the c101 connector under the intake that supplies the signal to the fuel injectors. Those are often corroded which leads to all sorts of problems like, dying, hard starts and other similar symptoms.

Start with the basics, fuel pressure/injector signal > spark/cps> and go from there.

[It's Soda Not Pop]

You have to rig up a fuel pressure gauge to the line and make sure you're getting fuel at the rail.

You could even just loosen the line to the rail and crank it and see if you see pressure shooting out. If you do and there still seems to be a fuel problem, I'd check the c101 connector under the intake that supplies the signal to the fuel injectors. Those are often corroded which leads to all sorts of problems like, dying, hard starts and other similar symptoms.

Start with the basics, fuel pressure/injector signal > spark/cps> and go from there.

I forgot about the C101. Yeah that can cause havoc.

[claye30]

Okay thanks. I hooked up a fuel pressure gauge to the fuel rail and the car fired and ran for maybe 10 seconds at 60ish psi and suddenly the fuel pressure dropped to 20psi and the engine sputterred out. I'm assuming it's fuel pump so I ordered one today and installing it tomorrow. I will check the C101 as well.

[moatilliatta]

What brand fuel pump did you find?

[claye30]

I got a new Delphi fuel pump and the car starts and runs reliably!!!

[claye30]

Okay little update. The car runs! Sorta. It consistently starts and runs, but not very good. It stutters, hesitates, and feels like it has intermittent power. The belts also squeal very loud. The car will stutter at 2k rpms then jump to like 5k-6k but the car isn't getting any power to the wheels. It also was smoking from around cylinder 5/6 on the exhaust manifold. I saw a puddle of oil so I think it is the valve cover leaking so I'll change that.