Hey guys,
I'm helping a friend with an M52 out of a 97 328iC swap into an 87 325e and we can't get it to fire up. The starter motor turns and battery is fully charged. We are keeping OBD2 and a DME was purchased with EWS deleted. No check engine light.
Today we checked for the essentials for starting the car: spark, air, and fuel. Spark was tested by removing the coil pack and spark plug from the valve cover and grounding it to the body, spark is confirmed. A quick compression test was done on each cylinder at WOT, however the car was not warm (obviously since car won't start) each cylinder was at 135 +/- 5 psi. I am unsure if these values are within spec or not, any insight would be great, but it is confirmed the motor is compressing. For fuel, the fuel pump primes when the key is turned on, and the pump operates when the starter is enabled. The injectors click when the motor turns as well, confirmed via screwdriver stethoscope. To confirm the two are working together, I removed the rail and injectors from the manifold to confirm the injectors were spraying, its ghetto I know, but the injectors are injecting fuel.
Here's where things get weird, the car will not fire up. I have a few reasons that might cause this, but want to get some confirmation and insight before continuing diagnostics.
1) We have not installed a fuel pressure regulator yet. We are running OBD2 and as you probably know, the FPR on the OBD2 E36 is located remotely with the 3/2 valve under the E36. My questions: Would no FPR cause a no start? Is running the 3/2 valve with FPR the best way to keep the OBD2 manifold and fuel rail? If you have any other suggestions on how to run the FPR, I would like to know.
2) The engine turning over sounds odd to me. It sounds like the engine is gurgling or like "blub-blub-blub-blub". I've never heard an engine sound like this when starting. I will attach a video to see if you notice anything odd (sorry for the vertical video). Just let me know if this sounds odd to you, or if its normal for M52s. My M54 and M20 have never sounded like this.
3) The car was in a front end collision and when replacing the E36 oil pan for the E34 oil pan, pieces of the timing chain guides were found so both were replaced. As far as I know, the chain did not jump teeth on the crankshaft sprocket. No pinging or valve-piston contact has occurred through hand turning the crankshaft as well as many attempts to start the motor. Is it possible the timing could be off? How would I be able to ensure the timing between crank and camshaft are correct?
CLIFF NOTES: This highlights my current thought process regarding the no-start of the M52. Spark, fuel, and compression are confirmed. Only potential issues could be lack of fuel pressure regulator, incorrect timing, or strange operation of the starter.
I'm still a noob with cars and this is the first engine swap I've ever helped with/done, however I am very familiar with the E30 and M20. Any help is greatly appreciated, if you need any more information for further diagnosis please let me know. I tried to include all the information needed for you guys to easily help if you've ever had this problem. Thanks guys!
I'm helping a friend with an M52 out of a 97 328iC swap into an 87 325e and we can't get it to fire up. The starter motor turns and battery is fully charged. We are keeping OBD2 and a DME was purchased with EWS deleted. No check engine light.
Today we checked for the essentials for starting the car: spark, air, and fuel. Spark was tested by removing the coil pack and spark plug from the valve cover and grounding it to the body, spark is confirmed. A quick compression test was done on each cylinder at WOT, however the car was not warm (obviously since car won't start) each cylinder was at 135 +/- 5 psi. I am unsure if these values are within spec or not, any insight would be great, but it is confirmed the motor is compressing. For fuel, the fuel pump primes when the key is turned on, and the pump operates when the starter is enabled. The injectors click when the motor turns as well, confirmed via screwdriver stethoscope. To confirm the two are working together, I removed the rail and injectors from the manifold to confirm the injectors were spraying, its ghetto I know, but the injectors are injecting fuel.
Here's where things get weird, the car will not fire up. I have a few reasons that might cause this, but want to get some confirmation and insight before continuing diagnostics.
1) We have not installed a fuel pressure regulator yet. We are running OBD2 and as you probably know, the FPR on the OBD2 E36 is located remotely with the 3/2 valve under the E36. My questions: Would no FPR cause a no start? Is running the 3/2 valve with FPR the best way to keep the OBD2 manifold and fuel rail? If you have any other suggestions on how to run the FPR, I would like to know.
2) The engine turning over sounds odd to me. It sounds like the engine is gurgling or like "blub-blub-blub-blub". I've never heard an engine sound like this when starting. I will attach a video to see if you notice anything odd (sorry for the vertical video). Just let me know if this sounds odd to you, or if its normal for M52s. My M54 and M20 have never sounded like this.
3) The car was in a front end collision and when replacing the E36 oil pan for the E34 oil pan, pieces of the timing chain guides were found so both were replaced. As far as I know, the chain did not jump teeth on the crankshaft sprocket. No pinging or valve-piston contact has occurred through hand turning the crankshaft as well as many attempts to start the motor. Is it possible the timing could be off? How would I be able to ensure the timing between crank and camshaft are correct?
CLIFF NOTES: This highlights my current thought process regarding the no-start of the M52. Spark, fuel, and compression are confirmed. Only potential issues could be lack of fuel pressure regulator, incorrect timing, or strange operation of the starter.
I'm still a noob with cars and this is the first engine swap I've ever helped with/done, however I am very familiar with the E30 and M20. Any help is greatly appreciated, if you need any more information for further diagnosis please let me know. I tried to include all the information needed for you guys to easily help if you've ever had this problem. Thanks guys!
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