89 911 3.2 running sluggish/sputters help
 

Hi all,

my car is running very sluggish especially between the area of 1-2k rpm.

I recently changed the o2 sensor, dme relay, fuel filter, ignition wires (magnecor 8mm), and sent in my dme to Steve Wong (no problem found with the dme).. I just ordered distributor cap/ rotor.

with the magnecor wires i got, what would be the best combination spark plugs i should go with.

Im going to take out the injectors soon and see how its shooting.

what else should i look for?

any help will be greatly appreciated.

Thanks
David

Hi David,

what about the valve clearance an timing? (did your car ran good before?)

Clogged cat?

Do you change the NTCII? The old one (single wire type, 13 mm) is prone to fail sporadic or temperature dependent and without a chance to measure an erratic state :mad: ...
A new one (two wire type, 14 mm) is highly recommended. I changed mine last year (after 146.000 km) before making any trouble ;).

LG Kassen

Thanks LG,

I will check it out.. is that the single wire connecting to the 3rd valve?

I have a feeling it might be the injectors though.. i will need to check that too.

Thanks again,
David

Hi David,

yes, it is the cylinder head temperature sensor mounted on the third cylinder.
See attached mounting instruction:p

http://forums.pelicanparts.com/uploa...1250532659.jpg

Further ideas:
- Fuel pressure (it depends on the pressure/vacuum in the intake manifold, refer to service manual)

LG Kassen

Thanks again LG,

When i unplug the sensor plug while car is idling,, it would idle erratic. but when i plug it back in, it runs a bit better... does that mean the sensor is ok?

I just changed the spark plugs to ngk bpr6es with recommended gap of .028, it idles a bit smoother.. but havent drove it yet.. i am still waiting for my cap and rotor to come before i check it out.. I think it might have something to do with the timing as well.. can hear put put put sounds while idling...

Thank again LG,,

The speed or the reference flywheel sensor could be marginal. That would cause poor idle and misses. Especially, if the refence sensor is bad it shift timing erratically. Not really easy to test unfortunately. You can measure their resistance but most times the fail intermittently. That is the engine runs like crap even though they check out with the Digital voltmeter.

The CHT should be the newer two-wire version. If not it is a good idea to replace it. Your test reveals that it does something hence it is not completely dead. But still it could be another intermittent problem.

Ingo

Thanks for the input Ingo, ill definitely check that out if its not the distributor/cap/coil or fuel injectors...

This issue is driving me crazy.

David

Does it run sluggish across the RPM range or just at 1-2K?

Did it come on suddenly or did it creep up on you?

If just the 1-2K range, I would take a look at your AFM. It can be tested on the car with a 9V battery and volt meter (do a search for instruction on this site). Over 75K, the traces can wear out at the lower end of travel and cause a lean condition in the lower RPMs. If it came on suddenly, I am not sure that I would suspect this. I am still new, so I am providing this insight based upon my research and troubleshooting.

Good luck.

its somewhat sluggish all the way.. from 1k - 5k.

It just sneaked up on me one day.. started poppin or shall i say sputtering and then become sluggish

Im going to do some servicing to the engine first i.e. oil change, valve adjustment and see what happens... you think the ignition coil can do something this erratic?

Thanks for the input.. always appreciated. :D

David

oil change won't help this problem, nor will a valve adjustment if the problem appeared suddenly , although they are good to do. I would say that a coil is a likely suspect and worth checking.

The problem sounds like you are going rich or not combusting properly. Stumbling and sputtering is typically not a siign of lean conditions (lean causes a continuous and sharp reduction in output, called a bog; Rich usually causes a stumble with the feeling of sputtering). Injectors are not likely to fail quickly across that many cylinders and one failed injector wouldn't cause these symptoms. It would be a moderate reduction in power across the range and would likely be worse at higher RPMs.

If it were me, I would focus first on ignition (verify the coil) and then look at reasons that could cause a rich condition (blocked intake or exhaust, fuel pressure, etc.). I am not experienced with the EFI issues, such as position sensors, but they certainly seem like culprites worth investigating. You should be able to easily test your CHT with an OHM meter. The connection is just above the two injector connectors, left of the throttle body.

Good luck

Thanks Lr172,

I just ordered an ignition coil and will install when it gets here. I personally dont know how to check if the ignition coil is bad or not.. so i decided i might as well purchase a new one.. have a spare if thats not the prob. I also did a so called rebuild of the afm meter.. I went in that black box and bent the copper lines a bit so it rides on new surfaces... i test drove it.. feel like a get a better response but still acts the same way..

my set up for ignition is magnecor wires, just newly purchased a month ago... new ngk bpr6es gapped to .028. and just changed the distributor cap/rotor. I also just replaced the o2 sensor

Now lets see if its the coil... im crossing my finger that it is.. this is driving me nuts... feels like i wanna sell my car.. but i put so much hard work into the conversion (993 body) that it would hurt me bones if i did sell it. check it out, heres a pic of my baby.

http://forums.pelicanparts.com/uploa...1250739108.jpg

Again,, thanks everyone for the input.. i really appreciated all your help.. i love this forum.:)

Looks awesome.

I need to ask - did these problems start after the installation of the new wires and plugs?

Too late now, but the coil can be tested with a simple ohm meter and the bentley manual. However, some tiimes the coil will only mis-behave when hot and the test will not show the problem. I hope that is it.

Larry

Thanks. The problems occurred before the new wires and plugs as a result of me changing it.

im crossing my fingers

Thanks again

just installed the coil.. and problem still exists... very laggy and when going on first gear.. i really have to press gas if not, it would wanna die out. i will check out the injectors soon.. and i wonder if it could be a cat clog.. hmmm...

im going nuts.. anyone wanna buy my car? haha

well all.. dont mean to bring this thread to life again.. but i still cant pinpoint the problem.. i changed the plugs, wires, cap, rotor, o2 sensor, ignition coil. I just changed the fuel pump today and went for a test drive.. it drove fine for about 1 mile and then the starvation problem came back.. and when i pulled over and checked the engine bay,, it has this distinctive smell.. somewhat like plastic or something like that burning.. sniffed the exhaust pipes and it was toxic.. what are the chances that it can be the catylic converter?

help.

Thanks
David

You said ordering cap/rot, meaning they are not replaced. Let see after they are reaplaced. Also, I don't see you list spark plugs.

You said ordering cap/rot, meaning they are not replaced. Let see after they are reaplaced. Also, I don't see you list spark plugs.
I was using platinum. The car ran great most of the time but was missing several times out of a year. After using the old copper/cheap plugs, never ever missed since then. Several years now.

that was an older post, all those were replaced. still having the starvation problem

thanks

i actually went back to ngk bpr6es but didnt fix prob

If changing the fuel pump improved things for a mile, I would spend a bit more time here. Have you changed the fuel filter? This is a more likely prospect for fuel starvation. Does it run well at higher RPM's? If so, fuel strarvation is not likely your problem.

If it only happens at the lower RPMs, I would test the AFM. This can cause the types of problems your experiencing. You need to pull the air filter and hook up a 9V battery for a real test. This will tell you if the traces in the AFM have gone bad. Do a search and you will find the method to do this. The traces can fail at the lower openings and still be good at the larger openings. There is info on how to repair this as well.

Good luck.