12/87 new engine problem

[Cabriolet]

so a local guy is having me put a new engine into his car. i built the engine for a car and then sold that car. lol.

this is my 13th m20 build, yes the timing belt is on correctly.

The car
12/87 325i convertible
153 brain
early fuel rail, early but separates injector harness.
new fuel pump
ran smoothly went dropped off.
300k+ miles
dropped off last weekend

The engine
-the head: 97k head, pressure tested, machined flat, 3 angle grind.
-the block: miles unknown, honed block, all new rings, bearings, m50nv 135mm rods, late model m20b25 pistons.
-the rest
new
m50 injectors
turner chip 153
272 IE billet cam
HD rockers and eccentrics
timingbelt,WP,radiator, thermostat, bmw head bolts, erling gasket set, goetze HG, belts, fuel line, plugs, wires, cap, rotor, all hoses.
170,170,160,170,165,170 psi hot compression -5 cranks.


The issue:
it runs rough at best
it will idle, but just barely
it bogs under even mild acceleration, no load, just driveway and is worse when driving. it dies under normal/heavy throttle response. light is barely ok.
Tried another DME no change, tried another good AFM no change, tried another KPS no change, cleaned the injector harness connector no change, cleaned the TPS plug no change.

any ideas?

i was able to do the cam break-in correctly and keep the engine at 2-3k rpms for 20min.

[Cabriolet]

Does no one have an answer?

[Andy.B]

Have you tested the fuel pressure? Could there be a kinked line somewhere? Could the pressure/return lines be crossed? Bad gas?
Could the catalytic converter be clogged?
How are all the ground points?
Are the spark plugs clean? Is the gap correct (I've had good and bad ones out of the box).
TPS?
Air leaks?

I have done builds/repairs where I addressed so many things in one job, I occasionally overlooked the basic stuff. Even when I was a professional technician, I would forget to check the basic things first sometimes. It is easy to look at the big picture, and forget that the battery terminal is only hand tight, or the connector you meant to come back to later is still dangling somewhere, or you didn't put an o-ring on when you test fit something, but you never took it back apart after the test fit, so there it is, bolted down, still missing the o-ring. You get the idea. Never be so confident in your work that you won't don't check the basics.

[Cabriolet]

Have you tested the fuel pressure? Could there be a kinked line somewhere?
Could the catalytic converter be clogged?
How are all the ground points?
Are the spark plugs clean? Is the gap correct (I've had good and bad ones out of the box).
TPS?
Air leaks?

we are going to test pressure tonight.
cat has to be good, the car drove there with it without issue and it was replaced recently.
checked gounds and they are good.
plugs are gapped correctly. however as stated 2 are clean 4 are brown, after the 20min break-in.
the TPS was working on the car and when unplugged makes the car worse.
air leaks, shouldn't have any since everything is brand new. and were checked thoroughly last night.

batt is tight wrench used by my dad as i watched, all connections checked, cleaned and 4x checked.

[kronus]

smoke test it, i've found vac leaks even after checking connections and the bogging sounds like classic large air leak symptoms

[Cabriolet]

smoke test it, i've found vac leaks even after checking connections and the bogging sounds like classic large air leak symptoms

i will try to get one and do that this week. thx

[kronus]

I use a super hokey one made out of VW hubcaps and a rag, you can make one out of a can pretty trivially

[Cabriolet]

faulty rebuilt injectors, provided by the car's owner. swapped in my stock ones i had laying around. car runs perfectly now.