P1140 code!! Arg... Yes I searched extensively.

[c4harpe13]

Hi everyone, First of all this is my first post, been a lurker since I purchased my 1996 318ti in the beginning of January. This forum has proven to be a very valuable resource in the short time I've had it. A little history on the car, when I purchased it it had a blown head gasket, which I changed with a ton of help from various threads here and the Bentley manual. It was done correctly However this damn P1140 code has me pulling my hair out. It has been throwing this code since my first drive in it. With a ton of searching I've come to understand this code deals with the signal between and readings from the MAF sensor and TPS. So far, to try and get rid of this I've changed the following parts: MAF (new from ebay), TPS, o2 sensor(Bosch) and the pcv valve ( I forget what BMW calls it). I've also searched extensively for vacuum leaks and checked the boot between the MAF and throttle body. The light went out for a short while after I changed the pcv (about 10 miles). It also went out for an extremely short period ( a couple miles) after I changed the tps. Everything else had no effect. If needed I can give some sensor readings from my code scanner software at various rpms. I am completely out of ideas, any help or ideas would be immensely appreciated. Outside of this the car runs fantastic and I'm really enjoying it.

[familytruckster]

Get the trim values from the live data.

I guess you saw my thread on that code.

[c4harpe13]

Yes I did. I'm glad I'm not the only one this has happened to :/.

Ok, the fuel trim at idle fully warmed up:
Short term- between +8 and +10 percent
Long term is at +2.3

Also, what is the MAF supposed to be at idle, I'm asking because I noticed some discrepancy between the old maf and new one. the old would usually show .6lb/min and the new one shows about .4lb/min. Also the idle is smooth but seems to waver up and down 30 or so rpms on my scanner.

Thank you for your quick reply

[familytruckster]

I'll check the maf numbers today. Different #'s are to be expected.

The trim #'s aren't too bad, mine were -25...

With trims that low, I'd say there is just a small vacuum leak. Have you replaced all of the vacuum lines? On the injectors and all?

[c4harpe13]

I haven't changed the lines on the injectors, they looked ok and didn't show any signs of leakage with a ton of carb cleaner sprayed all over them. However I am planing on changing those along with the injector o rings, just to rule things out. Plus it can't hurt. I changed the line from the valve cover to the pcv, along with the line to the fuel pressure regulator. What's the trim normally supposed to be at?

[familytruckster]

It should be at zero in a perfect world, but it won't toss a code for trim until it's over 20% IIRC.

My car is at +1.5 for long term and 3-5 for short. MAF reads ~2.7 gr/sec at idle.

[c4harpe13]

So I finally got a chance to mess with the car again this evening. I changed the vacuum hoses running to the injectors and the injector o-rings. I thought for sure this was the problem, when I was tearing it apart I noticed a small hole in the body of the fourth injector with looks like it was made with the tip of a tiny screwdriver. I'm constantly fixing previous owners "repairs" on this. But I digress, I patched the hole with some jb-weld, it was just a pinhole. Same damn code!!!! I reset it and it's back. However the fuel trim long term is at +6.3 after a week of driving it. Also I an hear a slight exhaust leak, could this potentially be a factor? And thank you again for your help, this is driving me up the wall.

[familytruckster]

Maybe, but I doubt it. I have always had a cracked header and it doesn't toss a code.

Might want to try tossing the old MAF on for the heck of it.
Have you replaced the fuel filter?

[c4harpe13]

I'l try tossing the old MAF on today and seeing if it makes a difference. I've swapped them a couple of times already after I've done stuff with no change. I haven't changed the fuel filter, could that potentially be causing this?

[c4harpe13]

So, I got the light off. Well for now, I haven't driven it yet hopefully it won't come back on. I changed the spark plugs back to the OE type, the previous owner had Bosch iridium plugs in there and I changed the vacuum hose to the brake booster.

[c4harpe13]

So, the damn thing is back. I drove 10 miles and it popped back on. I'm am seriously going nuts with this. Anybody have any other ideas or have been through this? On thing I noticed is my MAF reading seems to be much higher than yours, 2.7gr/sec=.35/pound/min. min is at .5. Any help would be greatly appreciated . ahhhh!

[familytruckster]

Weird. Checked the intake manifold for leaks? Throttle bodies for proper operation? Might be a wiring issue at this point, a ground issue or something.

[c4harpe13]

I checked the intake for leaks and replaced literally every single vacuum item at this point, even the DISA oring. I am thinking there is a possibility the ccvv I replaced is faulty. Last night I pulled the oil cap off while it was running and the damn thing nearly dies, started missing horribly like a major vacuum link. I'm not familiar with the operation of the pcv system on these, but does that sound like it's a faulty ccvv?

[familytruckster]

yes, it sure does. That's the exact symptom of a bad CCV.

Those things are dang expensive too.

[c4harpe13]

Ok, thanks. Looks like I'm dropping another 50 on one. ugh. I really like this car but one thing I've learned is there's nothing more expensive than a cheap bmw.