Author Topic: m42 issues...please help!! (Read 6807 times)

Matt-B · « **on:** June 04, 2008, 04:07:12 PM »

Ok so the other day I am going to meet up with a friend to hit up some local junkyards. On the way to the residence I see out of the corner of my eye the check engine light flash breifly.

fastforward 6 hours...

I am sitting at a light and my idle starts surging between 800 and 1200..800 and 1200...an so on.

Then the check engine light comes on again. (will do this periodically)

Today 6-3-08 on the way to and from school when I was shifting to 5th there was hesitation and lost power when I let off gas everything was fine. And every so often i lose power..

Have any of you guys had this problem and what could it be?

Small list of my i thinks..

Throttle position switch?
MAF sensor? or whole thing?
Crank position sensor?
Idle control valve?
Fuel pressure regulator?

I am hopefully going to Run a code reader on it tonight if he gets here

any response is appreciated
THX guys

Matt-B · « **Reply #1 on:** June 04, 2008, 07:37:40 PM »

Anyone?

EN318isPDX · « **Reply #2 on:** June 04, 2008, 10:09:53 PM »

Check into the vacuum lines around the intake and ICV. You most likely have some disconnected hoses or broken hoses. If not that you may want to check your fuel pressure.

Matt-B · « **Reply #3 on:** June 05, 2008, 03:01:31 AM »

Iwill check them and fasten them down.

Possibly the fuel pump??

Only when I am driving and it is intermitant

DOES ANYONE HAVE A CODEREADER IN THE PDX AREA?

peerless · « **Reply #4 on:** June 05, 2008, 10:08:39 AM »

Strange thing, my buddy had a very similar problem. Even after rebuilding the engine and replacing all the vacuum lines, etc.

We installed a new O2 sensor and the idle is pretty much rock solid and the check engine light stopped coming on.

I think he used a 95' 5.0 Mustang O2 sensor. Same wire colors and everything for half the price. You just have to do some minor splicing of the 4 wires.

Wise Old Dog · « **Reply #5 on:** June 05, 2008, 10:33:51 AM »

O2 is not made to last forever. It is a common item to fail and should be replaced as preventative maintenence. In other words, put a new one in if you have high miles. Don't wait for it to start giving you trouble. One less thing to give you problems.

peerless · « **Reply #6 on:** June 05, 2008, 11:10:03 AM »

Quote from: Wise Old Dog;50668

O2 is not made to last forever. It is a common item to fail and should be replaced as preventative maintenence. In other words, put a new one in if you have high miles. Don't wait for it to start giving you trouble. One less thing to give you problems.

This is good advice. I remember back in the late 80's, early 90's some cars had a 'emissions' light. This was just like a service indicator light, It would come on every 40,000 miles. This informed you to change the O2 sensor. It was easily reset and didn't actually monitor the O2 and was quickly done away with and was on a limited amount of Asian and US cars as I remember.

But if you had to have a Service Schedule for replacing the O2, I would say every 50-60K miles. A O2 sensor contains a natural crystal. This crystal is the only crystal in the world that naturally produces a varying voltage signal based on fluctuations in surrounding Oxygen. Since its just a natural crystal subjected to extreme temperatures and subjected to noxious chemicals and hydrocarbons, its amazing it lasts as long as it does.

Quote

An oxygen sensor, or lambda sensor, is an electronic device that measures the proportion of oxygen (O2) in the gas or liquid being analyzed. It was developed by Robert Bosch GmbH during the late 1960s under supervision by Dr. G�nter Bauman. The original sensing element is made with a thimble-shaped zirconia ceramic coated on both the exhaust and reference sides with a thin layer of platinum and comes in both heated and unheated forms.

http://en.wikipedia.org/wiki/Oxygen_sensor

Quote

Zirconium dioxide (ZrO2), sometimes known as zirconia, is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the rare mineral, baddeleyite. The high temperature cubic crystalline form, called 'cubic zirconia', is rarely, if ever, found in nature, but is synthesized in various colours for use as a gemstone. The cubic crystal structured variety cubic zirconia is the best-known diamond simulant.

http://en.wikipedia.org/wiki/Zirconia

Matt-B · « **Reply #7 on:** June 06, 2008, 02:21:40 AM »

Idle is fine

ONLY WHEN DRIVING DO I LOSE POWER

anyone else?

tony92ic · « **Reply #8 on:** June 06, 2008, 01:58:52 PM »

My wife's Mazda MPV experienced something similar.

No power with throttle, let off or light throttle it was okay. Check engine light was on.

Was somewhat intermittant over a couple of days. At first not bad, then it became undrivable.

It was a bad coil in her case.

May want to check them.

Good Luck.

kowalski · « **Reply #9 on:** June 06, 2008, 07:29:47 PM »

check your throttle possitioning sensor with a multi meter. sounds like its your tps...

Matt-B · « **Reply #10 on:** June 07, 2008, 02:14:49 PM »

what should the resistance be do you know cause i checked it and i am not sure if I checked it right?

I am picking up an e36 book today for reference

Matt-B · « **Reply #11 on:** June 07, 2008, 02:21:07 PM »

http://www.koperformance.com/online_ordering/make_n_model_search_catalog4.php?make_select=BMW&year_select=1991&model_select=E30318M|||70f23384c1acbedcaf5727021c405148&model_select_text=318i%20M42%20%28E30%20chassis%29&3flag=Y&group_id=F2&group_text=Fuel/Air%20Intake%20System&group_log=4493792&cat_select=822&cat_text=Air%20Flow%20Sensor&cat_log=4436856

And does anyone know if this AFM is worth my time if infact it is the problem?

Screaming M42 · « **Reply #12 on:** June 09, 2008, 02:44:30 PM »

i have the same problem. usually only after ive been sitting at a light for a while, the car will take off like normal, hit 2000 rpm and will feel "loaded up" almost like a 2-stroke, and if i floor it, after a second or so it will "blow out" and run just fine again. and my idle surges from time to time after ive been running it hard.

took it to get smogged today and it failed MISERABLY, they suggested the MAF was tired and was causing the car to run really rich. i am going to clean it today and see if it helps any.

SnPaC · « **Reply #13 on:** June 09, 2008, 08:05:30 PM »

Quote from: Screaming M42;50871

i have the same problem. usually only after ive been sitting at a light for a while, the car will take off like normal, hit 2000 rpm and will feel "loaded up" almost like a 2-stroke, and if i floor it, after a second or so it will "blow out" and run just fine again. and my idle surges from time to time after ive been running it hard.

took it to get smogged today and it failed MISERABLY, they suggested the MAF was tired and was causing the car to run really rich. i am going to clean it today and see if it helps any.

Can you post the SMOG readings? I also failed recently for NOx and HC. Still working on getting it sorted out

Screaming M42 · « **Reply #14 on:** June 10, 2008, 12:22:00 AM »

so for

15 mph HC = 203 of allowed 124 (fail)
CO = .67 of .78 (passed)
NO = 1806 of 815 (WTF?!)

25 mph HC = 140 of 98 (fail)
CO = .30 of .66 (pass)
NO = 616 of 754 (pass)

and i passed all the evap checks and visual stuff too. talked with some people and they said it was just running rich as all heck and the fact that i passed some at 25 mph means the cat is still good, which is hard to believe(PO drove it with a cracked head for 2000 miles!). and i guess the O2 sensor doesnt really do squat if the MAF is not working, but i have nooo idea. PLEASE correct me if I have mis-understood. this is my first exercise in primitive fuel injection.

these are CA test results.