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View Full Version : Troubles with the car - any ideas?


SebSter
06-23-2004, 02:20 PM
A couple of nights ago i was driving back home on the highway, and as soon as i get off the ramp and stop at a stop sign, my idle gets weird and the revs pulse up and down.

Then, I start driving a bit to drop my friend off...and the car gets a little shaky, kicking and shaking as the engine climbs the rev range. I thought I might have knocked a sparkplug wire loose so I stopped the car checked and it was all fine.

So I took friend home and went home for the night. In the morning I turned it on, the idle was decent for maybe 10 seconds and then the car died. So we looked at it with my dad, checked the plugs checked the connections, checked for air leaks or anything like that, couldnt find a problem.

Here's a list of the symptoms:

- Idles somewhat decent for the first 10 seconds when cold, as it warms a little engine dies
- To keep it alive I press the gas and two things happen:
- 1. Sounds like the engine is misfiring, hearing faint pops
- 2. Pressing the gas steady and holding the rev at say 2000rpm and not moving my foot at all, the rev jumps up and down.
- If I try to drive it holding the gas down, it dies after a couple of meters and the engine is hard to start after


Here's what we've done so far, not much due to limited tools and parts:

- Changed sparkplugs
- Checked sparkplug wires by pulling out each one while the engine was on and after pulling out each one the engine would die (which indicates that they were at least doign something)
- Checked oil, turned out it was low below the bottom line so we filled that up
- Engine gave a fault code, 1222 which is Lambda Control .. usually means the o2 sensor, but that was just replaced less than a month ago with a Bosch one.. coudlnt take it out and replace it with the old one because we didnt have the tool

Any ideas?

djcontra
06-23-2004, 02:29 PM
check your distributer cap, (if your car has one) or ignition coil(s), as well, check for air leaks, and if all else fails, it could be your mass air flow sensor.

bmdoubleya
06-23-2004, 04:45 PM
Originally posted by djcontra
check your distributer cap, (if your car has one) or ignition coil(s), as well, check for air leaks, and if all else fails, it could be your mass air flow sensor.

I'd say 100 % that its the MAF borrow someones and swap them before you spend the $500 I've seen this problem many times..

It could also be a crack in the ruber intake hose behind the MAF. Which is a easy fix with some duct tape.

addbhp
06-23-2004, 04:49 PM
Definitely a vacuum leak. All the tiny hoses that run around an engine dry up after all these years, and despite your best looking around the engine, they still can appear. Take to a mechanic you trust and he'll find it really quickly. Has happened to me about three times with my E30, but all hoses have now been replaced.

chromius
06-23-2004, 05:12 PM
if the AFM is shot you should be getting a fault code for that as well...I would think:confused: ..But yeah as everyone else said, sounds like an intake leak, or AFM problem.

Slowered318
06-23-2004, 05:27 PM
when was the last time you did the timeing belt? or adjusted your valves

SebSter
06-23-2004, 07:54 PM
thx for all the help guys, ill look into trying someone elses AFM and also getting the hoses checked

timing belt was changed about a year ago, and valve adjustment i have no idea when..not in the past year and 2 months that i have owned it though.

Skunk#1
06-24-2004, 07:40 PM
to check for vacuum leaks sparay the rubber hoses with carburetor cleaner, when it leaks into the airstrem into the engine the idle will raise and thecar will sound normal. you just found your leak.

The Sly
06-24-2004, 09:36 PM
Keep us in the loop, i am curious to find out !

SebSter
06-25-2004, 03:25 AM
Well, I tried a working AFM , it didnt fix anything..I still had the same problems...so at least i know what its not.

I havent checked for air leaks, the problem with ur method is that the engine doesnt stay running long enough to do that. But from a pretty thorough visual inspection I see no cracks or rips in the tubes.

Someone else suggested that it could perhaps be the fuel pressure regulator.

Other than that it could be the distributor cap...oxygen sensor, the computer gives the lambda control error which indicates o2 sensor, but it could just be a chain effect error.. (ie improper air/fuel mixture gives off different o2 reading to the sensor which tricks the computer into thinking that its at fault)

I dunno Im running out of ideas...may have to take it in to the dealer for a diagnostic.

GusRacer
06-25-2004, 04:12 AM
sounds similar to what i had....turned out to be my crank angle sensor....the mechanic re wired it (i had given up by this point) and its been sweet ever since.....it was a bitch of a problem, real hard to diagnose..good luck

chromius
06-25-2004, 09:34 AM
I'm pretty sure its not your O2 sensor, the idle control module dosn't use the reading from the O2. The car will even run fine if you unplug the O2 sensor. Try testing your fuel injectors...by measuring the resistance accross the terminals....I think for your car they should be low resistance 2-3ohms but don't quote me on that, it would say in the shop manual if you have one. Fuel pressure reg could be the problem....try unplugging the vacume hose to it, that will make the mixture more rich, and see if there is a change in how the car runs....or pull off the crank case ventilation tube and let some unmetered air in, this will lean out the mixture if it happens to be running too rich. see if that changes anything...:) But from what you described it sounds like its already running too lean, so try the vacume hose on the FPR.

djcontra
06-25-2004, 01:23 PM
since it's not the AFM, I'm leaning towards ignition problems, or perhaps even a dirty/bad sensor. The issues sound more and more like ignition problems. Check that dist cap, and check for water/moisture around the electronics and sparkplugs. If you have a bentley manual, you can do some ohms testing for the sensors. If you can't figure it out, then it might be worth it to spend the $100 to get it professionally diagnosed at the dealer.

paul christians
06-25-2004, 01:37 PM
come to the meet tonight......

snd84318i
06-25-2004, 04:48 PM
what kind of gas do you use . my car pops and ilde is radical some times . but twice i've changed gas type . like 87 to 89 recently i did 87 to 87 but different brand . and i sware as soon as my gas needle hit half way it started up . but my car doesnt shut off rightaway it just pops and jumps . when i press to gas to go it moves but no power very slow . i got out started tapping on my afm and pulling on the trottle cable and it stopped . good luck on solving your problem .

aascenzi
06-25-2004, 05:17 PM
Check the fuel pressure regulator, I had the same problem with mine. Also check the vacuum hose connected to it for leaks.*th-up*

SebSter
06-26-2004, 04:06 PM
thx for the help guys

i use 91octane+ only cuz of my chip so i know its not bad fuel.. other than that im gonna try finding a fuel pressure regulator now.

If anyone has one lying around pls let me know, thx.

Skunk#1
06-26-2004, 04:23 PM
octane doesn't make gas better or worst, it is only for detonation. the car would still run. the o2 sensor if not working the will run in a preprogammed default fuel regulation. it would still run just not optimum.it sound like you have a serious leak (air). you can spray carb cleaner in the intake tube while starting see if that helps, dont just hold it down but use bursts so as not to floos the engine. this should get it running, then switch to a different can or pull that one out and start spraying around the intake all hoses anywhere the air can get in. dont think that it has to be a hose, it could be a crack in the intake, gasket, or hose. if it fires but doesnt stay running then it most likely is fuel related. most of the fuel pressure regulators that go out dont let the car start, it will just turn over, but fire if you spray carb cleaner in them. you also might want to see if your fuel pump relay or pump is still good. anyway try some of this and let me know, i can further diagnose this i just need more info.

SebSter
06-26-2004, 04:45 PM
sweet thanks for the help.

the fuel pump is brand new so i know for sure that isnt the problem.

just curious what does it do if i spray carb cleaner into the intake tube? and im assuming ill need another person to do this with? or shoudl i start it normall then run over to the intake and spray it in?

now ur sure if the fuel pressure regulator was dead that the car wouldnt even start? can i rule that out as the problem?

johnoz
06-26-2004, 08:53 PM
Originally posted by SebSter
the fuel pump is brand new

Hey Sebster, how much did you pay for your fuel pump? Did you buy locally?

Thanks

SebSter
06-28-2004, 02:20 PM
johnoz, i paid about 300dollars and my mechanic got it for me

and good news, i took it in today, turns out the connections to the fuel pump were bad, so im gonna need a new fuel pump housing but for now it runs fine

it sucks i didnt even think to look there since i had just replaced the pump so recently i didnt think it would cause problems

Jon@Bimmersport
06-28-2004, 02:36 PM
shoulda been one of the first things to check, just in case there was a fault in it...since u replaced it and now this started..i dunno, jus wat i woulda done.

Hohner
07-05-2004, 04:13 AM
Make sure all your connections are correctly hooked up, unplug the negative terminal of your battery for an hour. Come back, plug it back in, and try starting the car. What you've done is a computer reset, this is one idea ...