So close, I can taste it. mmmm

[yert315]

I have been battling this small final problem with my m30b35 swap. Once this is fixed I'm Done. Here's what's going on:

It idles alright (could be better) and revs up to ~1700rpm fine. When it hits that 1700rpm mark and up the revs will cut out, catch, rev back up and cut out continuously.
I have replaced:
-tps
-afm
-cps
-plug wires
-spark plugs
-cap/rotor
-timing chain rails and tensioners (timing is still good)

I swapped out the ecu with a known good one as well.

I heard the cps has a specific distance from the crank wheel, but I can't find the specifications. Looks pretty damn close just looking at it, but i'd like to be sure since i did remove the cps mount.

What say ye?

[Doughnut]

This sounds like an injector problem to me - Have them flow tested and crack tested and replace the 'o' rings.

[bmw335isturbo]

fuel lines could be restricted check fuel rail and line from the tank

[yert315]

injectors have new o-rings and caps. We pulled the rail and turned the engine over and are getting fuel flow - all injectors are firing. I will try and find another set of injectors; the current ones have been giving me a bit of trouble.

I'll give it a shot and report back

[Lurker27]

Where did you pick up your caps? Mine were decimated when i pulled the injectors out. I am giving my injectors a xylene flush, but I haven't been able to source the caps.

Check your wiring to the fuel pump - I had a similar problem due to corrosion.

[yert315]

i got my caps and o-rings from Napa. They are from a 5.0L early 90's mustang.

I'll check the wiring as well. Thanks for the tip

[JoeMadoo]

If you have an o2 sensor plugged in, unplug it. A faulty o2 sensor caused my cutouts awhile back.

I have an extra set of 19# mustang injectors if you wanna give them a shot also. They have a better spary pattern than the stock ones.

[yert315]

The o2 sensor had been unplugged the entire time until I got a tip, from BigBronzeRim on mye28, that the motronic 1.3 from the m30's are touchy. He said that the computer relies on the o2 sensor more-so than the m20 setup. So I plugged it in for good measure.

I just picked up some design 3 19lb injectors tonight, which will be going in tomorrow. Also, I will be cleaning the spark plugs with some acetone (tip from a local car guy). We'll see what happens tomorrow.

[yert315]

Update:
still running like ass.
Got the design 3 injectors in, new spark plugs (copper), checked fuel pressure (good), and replaced ignition coil with a known working one.

Here's a video I shot today:

http://www.youtube.com/watch?v=S-Awp1Pp2x0

Seems like something electrical. I'm picking up a timing light tonight.

[bmw335isturbo]

that sounds like a timing problem does it backfire or pop you might have to check TDC the chain could be off a tooth would not know with out being their.
Best of luck

[yert315]

only when I try to go full throttle. It will sometimes pop/backfire and other times I will hear a loud ping from the valve under the valve cover.

I'll get a timing light on there today or tomorrow and see what that tells me. But I have a feeling I'm taking it apart again.

edit: I don't think the timing is off. Back when I had the bad afm, it would rev to 5k without the symptoms I have now. This started happening when I had to drive it over to the new house. It was running pig rich (half tank gone within 10 miles). When I was really low on fuel, I put about 2 gallons in, got back on the road, then the symptoms appeared.

[yert315]

Well, after quite a bit of testing the engine started running worse and worse. Last time I ran it, lots of squeeking/slight grinding from the head appeared. When it died (after letting off the throttle) it sounded like the cam was grinding on the rockers or something. I haven't touched it since then. I fear the first time I really drove the car and had it towed was the beginning of the downfall. Popped the valve cover off and didn't see any broken or worn pieces. I did notice that some rockers were not directly in line with the pushrod/lifter (not sure what it is called). The springs on the rocker arm rail seemed to push the rocker over more than it should. I think this may be what's making the noise from the head.

It wasn't making the cutting out symptoms recently, but I was unable to get it running smooth. Give it throttle, it would struggle, let off a little and it would smooth out for a few seconds before struggling again.

I don't know what to do now. I have been frustrated with this build since day 3 and this takes the cake. I dont know if I want t get an entirely new motor (m30) or just get rid of the car and start fresh.

[whiltebeitel]

I really wish I knew what to tell you. I'd love to see and M30 e30 in Texas! It sounds like maybe the plugs are getting extremely fouled from all the excess fuel. Does the FPR work correctly? If there's any way I can help you out, PLEASE let me know. I'm not exactly local, but I'm not on the opposite end of the earth.

[RickSloan]

this sounds alot like the frustration im going thru right now... mine doesnt idle tho and is ok at high revs...

im gonna keep my eye on this thread and will let you know if i get mine figured out

[yert315]

I really wish I knew what to tell you. I'd love to see and M30 e30 in Texas! It sounds like maybe the plugs are getting extremely fouled from all the excess fuel. Does the FPR work correctly? If there's any way I can help you out, PLEASE let me know. I'm not exactly local, but I'm not on the opposite end of the earth.

there's already an e30m30 owner in san antonio. I've been swapping out damn near every part from his over to mine to no avail.


I can't tell if my original problem was electrical or mechanical. Now I can't really diagnose it that it's running like ass. I'll take the valve cover off this weekend and inspect it. I noticed I had too much oil during/before this happened, so I drained it to the correct level. And that's when it just went to hell. I'll keep investigating, but my mechanical intelligence is limited, so we will see.