M42 wont idle after doing some stuff to it

[nickmp0wer]

I installed 19 lbs injectors, markd chip, removed and painted the intake manifold, and accedently left the AFM out in the rain.

now when it idles the rpms just get lower and lower and ussually it stalls. it revs fine though. I havent driven it yet because i need my dad to help me bleed the brakes so i might jsut need to go out and drive it but i wanna ask now. what might the problem be?

[Rob]

check your vacuum hoses first, might be the one on the bottom of the intake boot. If your AFM got wet, bummer.

[nickmp0wer]

yeah at first i left that vacum hose off but it still did it. now after running it more ive relized that if i "warm it up" a little it idles OK. I also changed the spark plugs from shitty platinum 4s to nice ones. and changed the fuel filter. any way to test the afm?

[e9nine]

Hopefully it's not your AFM. As Rob mentioned, check everything. Did you reconnect all the hoses the right way? Are you sure the intake manifold is secured the right way? There is a tiny hose that runs to the fuel rail. It is very easy to get it pinched when putting the intake manifold back on. If you need an m42 AFM, I believe I have one to spare.

G.Luck

[nickmp0wer]

ive checked and rechecked. I did the gas pedal thing and no codes came up. When i get it drivable which will hopfully be tonight im going to take it to the gas station to get some new gas, (stuff thats in there is probably about 2 months old) and im going to put in some fuel system cleaner for the new injectors.

[hamann318is]

Hopefully it's not your AFM. As Rob mentioned, check everything. Did you reconnect all the hoses the right way? Are you sure the intake manifold is secured the right way? There is a tiny hose that runs to the fuel rail. It is very easy to get it pinched when putting the intake manifold back on. If you need an m42 AFM, I believe I have one to spare.

G.Luck

The tiny fuel rail hose sucks big time. FYI.

[Rob]

Oh yeah, why 19lb injectors? Did dyno tuning tell you the stock injectors were maxed out?

[nickmp0wer]

yep.


actaully, i think/thought they would be nessary with a chip cam tuning intake and exhaust, and they were only $25 shipped, but maybe thats my problem, they are bad

[nickmp0wer]

just drove it a little bit and it idles now but it still doesnt seem to run very well. it also was giving the code

1216 Throttle Potentiometer This code is stored if a break or short-circuit occurs in the wiring to the Throttle Potentiometer or the potentiometer is defective. Damage at the throttle potentiometer connection is the most common cause of this fault.

Edit: i just remembered i disconnected the tps to see if it changed how it ran

[e9nine]

If you tugged on the TPS wire too hard while disconnecting it from the TB, it will fray inside the sleeve if the wire is brittle. Been there done that. Put some pressure on the TPS wire as u rev the car in from the throttle cable under the hood and see if it smoothes out. Usually that will throw an occasional check engine light though.

[Hick]

You neeed to give some time for the ECU to relearn, too many factors go into this issue. First off, the chip is made to work with stock injectors, so thats something the computer has to learn, second, asdjusted cam gears, another thing is has to relearn, and third, if you have a vaccume leak then the car would run very very poorly at all times [ifs it one thats enough to make the car stall] My m42 took some time to get back up to running order after it had sat with no battery for almost 6 months. Even tho thats the case, i could remove the oil cap and it would still run, representing a large vaccume leak

[nickmp0wer]

seems to be running fine after some driving

[nitro325is]

Oh yeah, why 19lb injectors? Did dyno tuning tell you the stock injectors were maxed out?

The 19 lb mustang injectors are a slight upgrade. Stock units on the 318is are the same flow as those found on M30 B35 engines. Check BMW ETK to confirm.

M30 B35/M42 Injectors are 19.82lbs @43.5psi
Mustang units are 19lbs@38psi = 20.33 lbs@43.5psi

His biggest benefit is going to be the better fuel atomization using the 4 nozzle design VS single.Assuming he got design II units.

[nickmp0wer]

are you sure the stock ones are 19? it runs really rich for a little after i unplug the battery and i dont think .5lbs more injectors would do that.

and my spark plugs had white shit all over them

and they were the injectors i got from you nitro325is

[nitro325is]

I am almost 100% sure the stock units are 19lbs.Here is my logic.It is common knowledge M30 B35 injectors are all 19lb units.
Now check your BMW ETK for either 85 and up 535/635 or whatever has an M30 B35 and then check the parts use.Lists the M42 as well.Do it vice versa looking up the M42 and it will list the M30 B35.

I think your problems stem from doing too many things at the same time and the ECU trying to cope with everything at the same time.Give it time like everyone else says and it will adjust.Clean the plugs again and just drive.If you keep reseting your starting all over again and will have to pull the plugs again.

BTW I thought blackish soot was rich and white was lean? Did you check the plugs condition BEFORE you put everything in or AFTER? Keep us updated.

Edit:Saw you siad its running fine now.So is everything back to normal?