Just performed a tuneup on my 86 635csi and the engine feels terrible now. My notes are below. Not sure if these issues are related to the parts I changed or purely coincidence (the latter would not surprise me). Any help would be appreciated. Link to some videos are below.
https://photos.app.goo.gl/KdQyUuPedUG8GkL98
https://photos.app.goo.gl/F5KnzcWpr1c1Upkb6
Problem: After tuneup, engine struggled to start and stay running. Engine would start, stumble, and die. Pressing the gas made the RPM climb slowly, but the engine stumbled/bucked as it climbed. Feels like a lawn mower engine or the timing is off.
Parts Changed: Distributor Cap (Bremi), Distributor Rotor (Bremi), Spark Plugs (Bosch WR9LS), Air Filter (Mahle), Valve Cover Gasket (Victor Reinz)
Cleaning: Outside of Plug Wires (shop towel and cleaner), Inside of Throttle Body + Plate with Brake Cleaner (did not remove), Inside of ICV with Brake Cleaner, Cylinder Head Surface with Scraper + Brake Cleaner on Rag, Inside of Valve Cover Breather Hose, Sanded Ground Wire Lug for Firewall-Valve Cover Attachment (confirmed its torqued on)
Measurements
Speed/Ref. Sensor - Both Okay
- 1-3 Terminal ~ 1029 & 1038 Ohms respectively
1-3 Terminal, 2-3 Terminal, ‘O.L’ displayed on my multimeter (hindsight, pretty sure I had the incorrect range selected)
One sensor’s connector end is cracked
Unplugged both and car would crank but not start
- Primary - 0.6-0.7 Ohms
Secondary - 5890 Ohms
Ignition Wires (including coil wire) - Okay
1 to 6 ~ 5700-6000 Ohms
Coil ~ 2100 Ohms
- Replaced distributor cap + rotor with original Bosch >> slight improvement >> engine started and stayed running– still runs really rough and sounds like a lawnmower engine when trying to climb through the RPM range
Removed all intake related hoses/boots up until the throttle body and inspected for cracks, no issues found
Noticed air filter was upside down– corrected
Pulled oil dipstick while running and the engine RPM dropped
Checked to make sure the valve cover is clamped evenly across the cylinder head and there are no gaps– confirmed
Jumped Fuel Pump Relay (pin 30 to pin 87), felt fuel going through feed line
Removed fuel feed line
Slightest bit of fuel came out of the line (kind of weird) >> I do have a fuel pressure gauge I can rig up to check the actual fuel pressure
Swapped Fuel Pump Relay with known good one - no change
Swapped Main Relay with known good one - no change