MY MOTOR EFFING SUCKS! (long)

[winstontj]

hope that got some attention....

I have a new ICV coming in the mail today (hopefully it will arrive today) from BLUNT... Maybe that will solve the problem.

When the motor is cold it cuts out, misses, bucks, idles low and is generally fcuked up. When it warms up it gets better but not a whole lot better. These problems recently started shortly after the purchase of the car so I'm not sure if they were already there or if I may have done something to cause this. Either way it's so bad the car is barely drivable and almost dangerous because of how it cuts out and stalls.

Recently I have replaced/done: Valves, plugs, wires, cap, rotor, injectors cleaned & replaced seals, BavAuto Adj FPR, intake hoses & TB cleaned and set TPS, MAF cleaned and tested, running 91 octane fuel, new fuel filter, air filter, new 02 sensor.... possibly more.

So when the car is cold I can hear something sucking like a vaccum opening and closing and the car bucks and stalls like a mo-fo when cold. It's really bad - barely drivable. It's like something is shorting and the motor dies. You'll be pulling away from a light in first under load the the car will totally crap out and die. if you are lucky it'll keep going and power through but not always. Idle is about 500rpm. Like I said I'm going to replace my ICV today/tomorrow when it arrives but what else could this be?

I don't know these cars that well and knowing that the TPS and MAF are good as well as the intake and fuel delivery/ignition... I just can't think of anything else outside the ECU or maybe chip???

Any help would be much appreciated. I have to drive for Easter this weekend and I really want this problem solved before we leave.

[NC325iC]

use a can of EFI safe carb cleaner and spray around, if your idle picks up you ahve a vac leak

make sure you spray were all youre gaskets are

if you can hear vacuum leaking then i doubt its the ecu, to my knowledge they dont just go bad if you dont mess with them

[jlevie]

When you say intake hoses, do you mean all the hoses that connect to the intake? And have you checked for an intake leak via the brake booster, oil dipstick, or oil filler cap? The booster is easy to check, just clamp off the hose between the intake and the check valve. A quick test for the dipstick is to seal it to the tube with tape. For the filler cap, just replace it (they're cheap).

The symptoms sound exactly like an intake leak and that's where I'd start...

[winstontj]

The symptoms sound exactly like an intake leak and that's where I'd start...

I agree and that's why this is killing me!!!!

When I resealed the intake & TB gaskets I used dabs of "liquid gasket" to seal them. I replaced all the hoses, booster (vacuum tested it and it's good) to TB hoses & check valves, valve cover to TB, ICV to intake boot, all of them... they are ALL tight and when I spray the shit out of the motor with carb & choke the idle is rock solid. There are no leaks (that I can find or spray). Even when I spray the shit out of the injector seats....

I visually inspected the heated wires (both of them) as well as tested the resistance under load, static, etc. all checks out as it should per the Ford manual (Ford Heated wire MAF)... The only thing is that damm ICV which measures on the ohm meter OK.. a little high but not bad only when I unplug it the idle does not move.

I'm hoping to be able to replace it this afternoon but it's all temperature dependant and something on the intake side....

[CarsSuck]

Have you checked the coolant temperature sensor? If it is faulty it will cause poor running and you didnt mention checking it. There is a sensor for the ECU and a separate one for the gauge cluster.

[winstontj]

Have you checked the coolant temperature sensor? If it is faulty it will cause poor running and you didnt mention checking it. There is a sensor for the ECU and a separate one for the gauge cluster.

hmmm... thank you. I will check that. I'm leaving the country for a week and the car is going back to the PO to get some body work done (valance & IS lip painted and installed. He's a big 24v 5-series guy but he said he'll take a look. At least he has a shop and does this for a living so he has access to better equipment for diagnostics. The gauge cluster temp thing flutters like crazy. I removed the cluster and tightened the back but it only got a little better. It could be an issue because no I have not checked either but I have a feeling that there could be buildup under there.

When you say intake hoses, do you mean all the hoses that connect to the intake? And have you checked for an intake leak via the brake booster, oil dipstick, or oil filler cap? The booster is easy to check, just clamp off the hose between the intake and the check valve. A quick test for the dipstick is to seal it to the tube with tape. For the filler cap, just replace it (they're cheap).

The symptoms sound exactly like an intake leak and that's where I'd start...

When I pop the dipstick or the oil filler cap there is no change in idle. When I unplug the ICV there is no change in idle. This bothers me....

It's not worth it to spray the oil cap or dipstick but when I spray the sh*t (fire extinguisher right next to me) out of the entire intake there is no change. Its a real stretch but perhaps a minor change when I spray 4,5 & 6 injector seats... but not much if any change. Could this be the cat? Car runs fine when it's heated up but runs like sh*t when it's cold.

Like last night. I drove from providence to boston. Car was fine on the highway, etc. I got back, put the hazards on and left the car to idle in front of the house while we unloaded our crap. Outside temp was around 32degrees F, when I came back down 5 minutes later whatever it is had cooled back down enough (because the outside temp was cold) that it started bucking again. A short drive with the rpm's up and it goes back away... So it could be in the intake or some type of sensor that is exposed to the air but subject to warming based on operating temps outside the thermostat....

[CarsSuck]

The gauge cluster temp thing flutters like crazy. I removed the cluster and tightened the back but it only got a little better.

I believe this would be from a coolant leak. My car does the same thing intermittently and I can see dried droplets of coolant on stuff under and aft of the coolant distribution thingy at the front of the head.

[NC325iC]

the ecu uses a seperate sensor from the instrument cluster

[winstontj]

the ecu uses a seperate sensor from the instrument cluster

PO did a lot of sketchy sh*t on the car electrical wise. I just grabbed my power inverter from my dad yesterday... I live in an apartment and park the car in a garage so now with the inverter I can use the soldering iron and repair some wires that have been hacked and temp repaired by me.

I'll look into both the ECU sensor and the gauge sensor. Strange they use different ones. Different locations??? I'll pull them, clean them and replace the copper rings. Those effers can really get some buildup on them.

No coolant leaks - Timing belt & water pump were just done so there could be a loose wire but no coolant leaks. Only thing leaking is oil from the filter housing.

[NC325iC]

theyre rightnext to eachother on the thermostat housing

[bmwcr89]

is the engine light on?? If it is... Check the code... http://www.unofficialbmw.com/repair_faqs/motronic.html

You might have a wiring probably on the fuel injectors harness... This is what happend to me... the harness was badly cover with green crap.... If it is the problem then change the engine harness or cut the wires yourself and solder them(this what I did)...

I went down that road where I have to check everything from the ICV, TPS, AFM, vacuum leak, and etc. Pain in the ass! But once I've learn from STUCK from Bimmerforums.com... that it might be my injector harness... Solve my problem!

for the idle problem.... Adjust the stop screw!

[bmwcr89]

[CarsSuck]

is that corrosion from drippy hoses?

I've heard of corroison of the main wiring harness being caused by coolant leaks at the throttle body.

winstontj, I would rule out a leaky hose just because the timing belt and water pump were replaced. Once scale builds up on the aluminum parts it makes it much more difficult for a hose to seal around a fitting. I've replaced all but one or two coolant hoses, timing belt, and water pump in the last 10k miles and I have a leak from a new hose. Its not a bad leak, I just top of the coolant with a cup or two of mix every few thousand miles.

[winstontj]

is the engine light on?? If it is... Check the code... http://www.unofficialbmw.com/repair_faqs/motronic.html

You might have a wiring probably on the fuel injectors harness... This is what happend to me... the harness was badly cover with green crap.... If it is the problem then change the engine harness or cut the wires yourself and solder them(this what I did)...

I went down that road where I have to check everything from the ICV, TPS, AFM, vacuum leak, and etc. Pain in the ass! But once I've learn from STUCK from Bimmerforums.com... that it might be my injector harness... Solve my problem!

for the idle problem.... Adjust the stop screw!

Only time the check engine light is on is when the motor craps out/cuts out. Occasionally it's on but if you rev the motor up to 4,000 or so it goes away. All the goodies check out with the volt/ohm meter.

PO said there is a temp/thermo sensor under the intake manifold? is this true? There is no stop screw.... well there is one for the throttle plate and I adjusted the throttle plate properly and reset the TPS properly, then tested it with the volt meter. I do not have an ICM or an adjustment screw on the ICV.

Thanks for all your help everyone. I finally feel like I'm starting to get somewhere.....

[winstontj]

is that corrosion from drippy hoses?

I've heard of corroison of the main wiring harness being caused by coolant leaks at the throttle body.

winstontj, I would rule out a leaky hose just because the timing belt and water pump were replaced. Once scale builds up on the aluminum parts it makes it much more difficult for a hose to seal around a fitting. I've replaced all but one or two coolant hoses, timing belt, and water pump in the last 10k miles and I have a leak from a new hose. Its not a bad leak, I just top of the coolant with a cup or two of mix every few thousand miles.

PO has a tumbler... He's a pretty standup guy. He put all the stuff in the parts wash then in the media blaster, then tumbler, then painted the stuff.... it's all like spotless & nicer than new when he was done. I was totally shocked... I went to pick up the car and he was like "umm.... not ready yet... give me two more days..." I was so pissed for those two days but then when I picked up the car he says "I smelled fuel so we pulled the tank and replaced it, also we did a timing belt, water pump, oil change & a whole other list of things..." I was shocked...