EASY 100 BUCKS! calling all e30 masters

[smashed s4]

So i swapped in a replacement m42 into my 91 318is. Kept the existing harness and DME from the old m42. changed a bunch of stuff, h20 pump, timing tensioner piston, VCG, upper oil pan bolts, lower oil pan bolts, did the intake mess blah blah.

anyway, so the car cranks, and barely starts for a split second then dies

sounds like air is escaping from SOMEWHERE, and there is a huge BOOM and rattle from the airbox.


we have diagnosed this:
-getting fuel
-getting spark
-working AFM
-working fuel pump
-fuel lines are CORRECT
-swapped in 2 different CLEAN ICVs

whoever can diagnose, or even come to my house (san jose, ca) and figure this out. i will personally paypal them 100 bucks...


408-772-1275

thanks!

im in the south bay area!

[E30_Pare]

You should take quick vid. Would make it a little bit easier to diagnose.

Spray some starter fluid down the afm & fire it up.

[ADlBOO]

Almost sounds like bad timing.

[bmw325csi]

Did you check for intake leaks?

[smashed s4]

Stay tuned for a video tomorrow. Starter fluid into the AFM? Or in the intake?
I checked for intake leaks. To my eye, nothing. I'll take an extensive video of start up and the engine bay tomorrow.

[E30_Pare]

U should check if your at tdc then crank. Starter fluid is just a way to get you started if your lines aren't primed yet.

[Thizzelle]

double check all electrical connections, check ignition rotor and cap.

[reelizmpro]

First, how do you know the replacement engine is good? Compression and leak down test?

[smashed s4]

i can confirm that the replacement motor is good. saw it running before i bought it

[AlphaE]

I may be crazy but sound like ur exhaust is plugged. Runs enough to build pressure, can't get rid of pressure, dies, pressure leaks back through intake and air filter. Need vid. What's this boom? Like backfire? Sound mechanicals related not electrical. Cam timing is off. Exhaust valve hung up,exhuast system plugged. Something along those lines.

[vert_this]

what actually killed the previous motor?

[M3 Ryan]

Clogged Exhaust. Was there a rag in your manifolds during the work that got forgotten?
To the guy that said cap/rotor- it's an m42 with waste spark DIS, no cap or rotor.
Also check that crank sensor and can sensors are ok as this motor will surely not run if either of those are a miss.

[DÌEGØ]

I have more questions than answers lol but I would start with a compression test. Sounds like either your valve timing is off or you have an intake valve that is not seating.....Allso check the spark plugs.
I'll have to see the video