ugh about to throw in the towel + does anyone have an AFM for sale cheap
07-30-2008, 05:41 PM
#1
Race Director
Thread Starter
ugh about to throw in the towel + does anyone have an AFM for sale cheap
My 951 is a total POS. It has been giving me problems constantly and now has a new set of problems.
It only wants to start once per day and will run OK (but not as smooth as it should and has) for about 20 minutes. It idles at a steady 800-900 RPM with 18-20" of vac on cold startup, but runs lean according to both my narrowband and wideband lc-1 @ a steady 15- 16:1.
After about 20 minutes of idling -- after it died last time I don't trust going anywhere in this condition -- it no longer revs cleanly and want to die. I pull the plugs and they are seriously fouled (seems like oil and fuel)
Compression is 150psi -\+ 5psi on every cylinder and no coolant loss or overheating.
Mods are:
60-1 hifi, huntley racing MAF with arc-2HR, maxtronic\maxtune
I have replaced:
TPS
DME\KLR
Coil
Plugs\Plug wires
Speed & Ref sensors + checked the adjustment which was spot on
Rotor\Cap
FPR\Dampner
O2 Sensor
DME Temp Sensor
Fuel Filter
Every vac line\coupling\clamp
The only things I haven't replaced are the Maxtronic, the wiring harness, or the MAF (but I have a used one I can install)
On top of all of this my car now starts to blow some serious oil when as soon as it starts to boost (or is in low vac) and I suspect my turbo
I know I have had endless problems with this car and this is probably my 600th thread about my 951's issues.. but does anyone have any suggestions on what to do next. I'm also for the first time ever asking if anyone wants to come by and give it a look because I think my frustration is clouding my thought..
> I am considering going to a stock AFM setup and installing the stock harness w\ maxtronic..
thanks
mike
It only wants to start once per day and will run OK (but not as smooth as it should and has) for about 20 minutes. It idles at a steady 800-900 RPM with 18-20" of vac on cold startup, but runs lean according to both my narrowband and wideband lc-1 @ a steady 15- 16:1.
After about 20 minutes of idling -- after it died last time I don't trust going anywhere in this condition -- it no longer revs cleanly and want to die. I pull the plugs and they are seriously fouled (seems like oil and fuel)
Compression is 150psi -\+ 5psi on every cylinder and no coolant loss or overheating.
Mods are:
60-1 hifi, huntley racing MAF with arc-2HR, maxtronic\maxtune
I have replaced:
TPS
DME\KLR
Coil
Plugs\Plug wires
Speed & Ref sensors + checked the adjustment which was spot on
Rotor\Cap
FPR\Dampner
O2 Sensor
DME Temp Sensor
Fuel Filter
Every vac line\coupling\clamp
The only things I haven't replaced are the Maxtronic, the wiring harness, or the MAF (but I have a used one I can install)
On top of all of this my car now starts to blow some serious oil when as soon as it starts to boost (or is in low vac) and I suspect my turbo
I know I have had endless problems with this car and this is probably my 600th thread about my 951's issues.. but does anyone have any suggestions on what to do next. I'm also for the first time ever asking if anyone wants to come by and give it a look because I think my frustration is clouding my thought..
> I am considering going to a stock AFM setup and installing the stock harness w\ maxtronic..
thanks
mike
07-30-2008, 06:30 PM
#3
Rennlist Member
Mike,
Hang in there. I kept having wierd running issues and even though I got a new rotor and cap (changed at a reputatble mechanic, then screwed back in again at another mechanic). I couldn't figure it out and finally one of hte mechanics noticed the rotor kept getting loose and hanging wierd. I'd check that again.
Hang in there. I kept having wierd running issues and even though I got a new rotor and cap (changed at a reputatble mechanic, then screwed back in again at another mechanic). I couldn't figure it out and finally one of hte mechanics noticed the rotor kept getting loose and hanging wierd. I'd check that again.
07-30-2008, 07:15 PM
#6
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Double check the wiring to the Huntley MAF. I have never installed a MAF on a 944 T, but I assume it requires some wiring work. Also, check the ignition amplifier. I believe it is part of the DME, so you may need another DME to test. I had a similar problem in a 928 that was cleared up by changing the ignition amplifier.
07-30-2008, 07:26 PM
#7
Race Car
IMO the problem may lie within the oiling problem.
If your turbo is leaking via the coldside it may be allowing a ton of oil to cause some to the problems IE: TPS can get contaminated, Maf can get coated with oil if it has a recirc BOV.
Persoanlly I would in no particular order:
try to get Plugs changed out.
Pull the charge tubes and clean them out.
clean theTPS with electric cleaner and allow to dry. Test it
clean the MAF
check the AOS vent to make sure it is not kinked
then
run it for a bit and pull the charge tubes to see if you are getting oil past the turbo rings. If it runs good for a bit but starts to get oil contaminated you may have then found your TOTAL problem if not at least you will determine the turbo's condition.
These problems such believe me I chased a stupid bad injector for quite awhile.
If your turbo is leaking via the coldside it may be allowing a ton of oil to cause some to the problems IE: TPS can get contaminated, Maf can get coated with oil if it has a recirc BOV.
Persoanlly I would in no particular order:
try to get Plugs changed out.
Pull the charge tubes and clean them out.
clean theTPS with electric cleaner and allow to dry. Test it
clean the MAF
check the AOS vent to make sure it is not kinked
then
run it for a bit and pull the charge tubes to see if you are getting oil past the turbo rings. If it runs good for a bit but starts to get oil contaminated you may have then found your TOTAL problem if not at least you will determine the turbo's condition.
These problems such believe me I chased a stupid bad injector for quite awhile.
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07-30-2008, 07:35 PM
#8
Burning Brakes
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Do you have a intake air temperature sensor sending info to the DME/MAF? Just thinking that if you do have the temp sensor may be bad feeding the wrong info and causing the car to go rich after it warms up.
Another thing to try is cleaning the MAF wire sensor with contact cleaner and rag to see if it has developed a film due to too much oil in the intake track. If it works better after that then trace down the oil source.
Another thing to try is cleaning the MAF wire sensor with contact cleaner and rag to see if it has developed a film due to too much oil in the intake track. If it works better after that then trace down the oil source.
07-30-2008, 08:31 PM
#9
Race Director
Thread Starter
hey guys, thanks for the support..
I'm also suspecting maybe a fuel injector because my o2 sensors are reading lean but my plugs are wet with fuel and when I add fuel with my arc-2 it starts to die out?? I saw this online
The ISV hasn't been replaced but is covered in high temp epoxy (pressure tested to 30psi) and operates as it should. DME has also been replaced. I don't have a temp sensor in the MAF, but that is a good idea.
Sid- thanks for the suggestions.. I was thinking that all the oil could contribute to the problem. My hardpipes and intake piping get lots of oil in them fairly quick. I'm kinda upset about that as just a few weeks ago that problem didn't exist
John - are you in NY yet? I can't wait to check out your car.. its one of my favorites on the list
I'm also suspecting maybe a fuel injector because my o2 sensors are reading lean but my plugs are wet with fuel and when I add fuel with my arc-2 it starts to die out?? I saw this online
FUEL INJECTOR CLOGGING
It doesn't take much of a restriction in an injector to lean out the fuel mixture. A restriction of only 8% to 10% in a single fuel injector can be enough to cause a misfire. When this occurs, unburned oxygen enters the exhaust and makes the O2 sensor read lean. On older multiport systems that fire the injectors simultaneously, the computer compensates by increasing the "on" time of all the injectors, which can create an overly rich fuel condition in the other cylinders.
In turbocharged engines, dirty injectors can have a dangerous leaning effect that may lead to engine-damaging detonation. When the engine is under boost and higher rpms, it needs all the fuel the injectors can deliver. If the injectors are dirty and can't keep up with the engine's demands, the fuel mixture will lean out, causing detonation to occur.
It doesn't take much of a restriction in an injector to lean out the fuel mixture. A restriction of only 8% to 10% in a single fuel injector can be enough to cause a misfire. When this occurs, unburned oxygen enters the exhaust and makes the O2 sensor read lean. On older multiport systems that fire the injectors simultaneously, the computer compensates by increasing the "on" time of all the injectors, which can create an overly rich fuel condition in the other cylinders.
In turbocharged engines, dirty injectors can have a dangerous leaning effect that may lead to engine-damaging detonation. When the engine is under boost and higher rpms, it needs all the fuel the injectors can deliver. If the injectors are dirty and can't keep up with the engine's demands, the fuel mixture will lean out, causing detonation to occur.
The ISV hasn't been replaced but is covered in high temp epoxy (pressure tested to 30psi) and operates as it should. DME has also been replaced. I don't have a temp sensor in the MAF, but that is a good idea.
Sid- thanks for the suggestions.. I was thinking that all the oil could contribute to the problem. My hardpipes and intake piping get lots of oil in them fairly quick. I'm kinda upset about that as just a few weeks ago that problem didn't exist
John - are you in NY yet? I can't wait to check out your car.. its one of my favorites on the list
07-30-2008, 09:55 PM
#11
Race Director
Thread Starter
Do you think a wiring or chip image related (maxtronic) would cause this overly rich misfire?
I'm ready to buy whatever I need to to make this car work...turbo rebuild, new injectors, etc. I've spent way too much money on this piece, but sharing a car with my brother when we have different jobs etc is getting to be a problem
edit: I'm thinking this is similar to how my car was acting when the FPR went bad. I replaced it with a new one from autozone about 6-7 months ago. I smell a tiny bit of gas in the vac line, but it holds vac. Worth exchanging for a new one? (hope I kept the reciept..)
I'm ready to buy whatever I need to to make this car work...turbo rebuild, new injectors, etc. I've spent way too much money on this piece, but sharing a car with my brother when we have different jobs etc is getting to be a problem
edit: I'm thinking this is similar to how my car was acting when the FPR went bad. I replaced it with a new one from autozone about 6-7 months ago. I smell a tiny bit of gas in the vac line, but it holds vac. Worth exchanging for a new one? (hope I kept the reciept..)
Last edited by MM951; 07-30-2008 at 10:15 PM.
07-30-2008, 10:15 PM
#12
Burning Brakes
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An overly rich mixture can come from a bunch of things. It could be the chip image, but if it ran well with the chip image and Maxtronic at one point then I would look elsewhere. Since you have eliminated, or at least think you have eliminated plugs wires etc, then I thought that your MAF hot wire element may be getting residue on it which could cause it to be sending the wrong signal to the chips, this could be either too much or too little voltage for the given airflow. I have read that some of the factory MAF sensors actually put a voltage through the hot wire after shut down to clean the wire. I don't believe any of our after market MAF systems do this so I would suggest trying to clean the MAF wire as another possibility.
The ARC2 could be modifying the signal incorrectly but I don't know how to check any of that. If you are getting excessive oil in the intake track you do need to figure out where it is coming from. You might want to try cleaning the intake and intercooler and then hook up a catch can and leave it unconnected back to the intake. Drive it and see if the oil shows back up in the intake. If so then you probably have a turbo leaking oil into the compressor housing.
The ARC2 could be modifying the signal incorrectly but I don't know how to check any of that. If you are getting excessive oil in the intake track you do need to figure out where it is coming from. You might want to try cleaning the intake and intercooler and then hook up a catch can and leave it unconnected back to the intake. Drive it and see if the oil shows back up in the intake. If so then you probably have a turbo leaking oil into the compressor housing.
07-31-2008, 01:51 PM
#14
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I would check the turbo out first.
Regards
Graham
07-31-2008, 10:02 PM
#15
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When you replaced your FPR from autozone did you get a bosch 3bar?
It is helpfull to switch to an AFM to rule things out when you diagnose. I always keep mine handy for this. Make sure you swap over and pull the taps from the ARC.
It is helpfull to switch to an AFM to rule things out when you diagnose. I always keep mine handy for this. Make sure you swap over and pull the taps from the ARC.