M30 chokes with more than 1/3 throttle

[cernymuz]

Hi,
My swapped M30 started recently acting weird. When I give it more than, say 1/3 of throttle, it stops revving, but chokes/stalls and backfires instead. If I hold the throttle below "the threshold position", it will rev all the way up, but once I give it more, it chokes.

We checked the spark-plugs already, they are still like new and unlikely to cause the issue.

Any ideas? Help please

[F34R]

Vacuum leak my friend. I have seen this many times after I do a swap. All it takes is a little hole or a cracked hose. I had all my lines tighten perfect and it still choked out. Removed the FPR 1/4" hose the hooks to the intake manifold on the bottom. Had a little crack and it would leak. Swapped it out and it runs perfect.

[cernymuz]

Thanks! It makes sense, the engine idles high too. Would you happen to know if the M30B30 hoses are the same as M30B35?
Edit: NVM, they fit

[kylelauffer]

Of that doesn't work check your throttle position sensor

[cernymuz]

So it turns out the issue was with distributor

[nick526]

Care to elaborate? Worn parts? Loose rotor?

[FredDeuel]

Might as well check your wires while you're at it, and all the vac lines/tubes, only takes a few minutes and gives some piece of mind. I've been stranded a few times because a rip in the intake boot.