Misfire/dies out in 2nd gear and over i suppose

[Sjokolademelk]

Hey guys! first post on the forum.

Been looking all over the web and every forum i can find for anwsers.
Hoping to get some help here.

Bought the car with a destroyed engine, and just got done rebuilding it, and now i'm having some issues.
First the car idled fine until heating up where it misfired and died out. found it to be bad o2 sensor, changed it and it idled and revs "fine"

Now i'm having issues driving it, took it for a drive and 1st gear was fine.
2nd gear however, car completely shuts off as soon as i let the clutch out (10-15km/h circa)

cant seem to figure the problem out as the car runs fine in 1st gear, can rev fine and high both while driving and while idling.

What's been done so far
*fuel filter
*Spark plugs
*Plug wires
*All 4 coils changed
*Cleaned ICV
*Coolant temp sensors
*ALL GASKETS CHANGED
*charcoal canister delete

bad afm?
bad gas? (gas about 1 year old)
vacuum leak?
bad cps?
fuel pressur regulator?

Where to start and how to diagnose the different parts?
best regards.

[bmwman91]

When you drive in first gear, are you babying it or can you get on the gas pedal all the way? If you were just operating in first gear at a low load then maybe the issue is more apparent in second gear when demanding a little more power. Go give it a test and report back. Also, see if it changes at all between being cold and fully warmed up.

When you did the rebuild, did you happen to have the plastic cover off of the wire harness up on the firewall? And if yes, did you accidentally plug in a little black single-wire connector that might have looked like it was accidentally unplugged? If yes to that, then it might be your issue. On cars equipped with an O2 sensor and catalytic converter, that little connector is supposed to be unplugged, and plugging it in on a car with an O2 sensor causes all sorts of issues with how the engine runs (or doesn't).

[prisonerofdoom83]

I had something similar but 24v swapped ended up being the tps . Not the same but my friend with an m42 said he had my symptoms and it ended up being tps on his m42

[Sjokolademelk]

I had something similar but 24v swapped ended up being the tps . Not the same but my friend with an m42 said he had my symptoms and it ended up being tps on his m42

Thanks for reply!
i suppose it can be anything at this point, almost everything is changed and is brand new.
but if it is the tps it would have acted the same way in idle/first gear?
i can rev it to the limiter without any hesitation while its in first gear and still standing.

[Sjokolademelk]

When you drive in first gear, are you babying it or can you get on the gas pedal all the way? If you were just operating in first gear at a low load then maybe the issue is more apparent in second gear when demanding a little more power. Go give it a test and report back. Also, see if it changes at all between being cold and fully warmed up.

When you did the rebuild, did you happen to have the plastic cover off of the wire harness up on the firewall? And if yes, did you accidentally plug in a little black single-wire connector that might have looked like it was accidentally unplugged? If yes to that, then it might be your issue. On cars equipped with an O2 sensor and catalytic converter, that little connector is supposed to be unplugged, and plugging it in on a car with an O2 sensor causes all sorts of issues with how the engine runs (or doesn't).

i think the plug you are talking about is still unplugged, if it's a single wire plug around the brake booster area?

When i drive it in first gear i can give it WOT without any problems, tried going to 2nd gear with 1000rpm's and 6000rpms with the same problem
tried with cold car and half needle with 0 to no difference.

however my idle is also kinda shabby, goes up/down by like 50rpms from 750 regularly

[prisonerofdoom83]

Have you tried the stomp test? I think that can also rule it’s a bad tps if you can’t get it to work . Not 100% in that . My stomp test never worked . But I haven’t tried with the new TPS yet .

Thanks for reply!
i suppose it can be anything at this point, almost everything is changed and is brand new.
but if it is the tps it would have acted the same way in idle/first gear?
i can rev it to the limiter without any hesitation while its in first gear and still standing.

[Sjokolademelk]

Have you tried the stomp test? I think that can also rule it’s a bad tps if you can’t get it to work . Not 100% in that . My stomp test never worked . But I haven’t tried with the new TPS yet .

I've tried stomp test yes! but nothing comes up :P think my check engine light has been disconnected or bulb gone bad.
also tried to use 2 different diagnostics tools but wont connect and show any fault codes...
so i've had to manually diagnose so far..
checked every vacuum related component/hose today with quick start and ruled out vacuum leak.

planing on checking the values of the AFM with the correct tools next. anyone know the different values?

[Sjokolademelk]

a slight update here.
Noticed it as i started the car the first time ever that the fuel pump was insanely noisy, constant "whining" dont know if these older pumps are like this or?
starting to think the culprit may be a faulty AFM or fuel pump?

[Sjokolademelk]

Ordered a bunch of new parts again, hoping something will fix my problems, after this order has arrived i’ll make a new update
ordered:
*tps
*fuel pressure regulator
*new injectors
*new gas pumps (internal)
*new gas pump (external)
*new DME (175)
*new afm

will be changing 1 and 1 part to see what eventually fixes the problem and i’ll update here.

after everything listed above is changed, everything related to the engine in any way has been replaced. Except cam/crank sensors.

also going to 9v and clean my icv in hopes that idle improves :)

also does anyone have a good and reliable way to «smoke test» or check for vac leaks?
have checked it with cigar smoke, and carb cleaner. No leaks so far.