Help Please 1989 S4 stops running like it got hot, but temp is good
07-24-2012, 10:14 PM
#46
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Before you powder coat you remove the flappy mechanism's bits and the bearings for the shaft. When it comes back you may need to Dremel-out the bearing wells before you press new bearings in. Then you install the flappy bits.
Oh... take pictures before you remove the flappy bits.
07-25-2012, 12:33 AM
#47
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and on that now, it was not the temp II. Problem persisted and I tracked the noise of the fuel pump and noticed that it would shut off right before the car would. I have a 2nd 044 and have installed it ... car seemed to run real strong again with it in, but the test will be the drive to Phoenix.... will keep every one posted.
if its not that, next on the list will be the MAF...
07-25-2012, 11:16 AM
#49
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Yes, I feel the same way. Half way to phoenix (cool morning lucky for me) and it is happened again.
What is odd is the restriction happens slowly, meaning that I get "capped" on my RPM level slowly. I stopped for breakfast, but for 2o-25 min, I had the full spectrum and over the next 30ish min the max has slowly reduced to just slightly over 3K, and I know would be a shut off soon...
I am beginning to think, once I get it back to Tucson (having the paint fixed where needed from the paint job) that I am going to swap the temp 2 sensor... I did clean it up, but I am going to do a little more and put another one on first to eliminate it as a source of issues...
I may, or most likely will replace the 044 with a pump for an 87/88 like I did on my other 89. If for nothing else but voice reduction. Damn those pumps screen like champ.
Bill,
What happens when the MAF starts to fail? I can also imagine the CPS could due this as well. I also need to understand what the knock failure mechanisms are, but I do not believe those are contributing here.
What scares me is it might be more than one issue contributing here (044 pump power draw and something, but not sure)...
Fun fun fun...
07-25-2012, 11:50 AM
#50
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Well, if it is temp II, there should be some evidence the car is running very rich - Sooty plugs, black sooty, smelly exhaust - when the incidents occur. The plugs will be wet if you pull any right after failed attempts to restart. If the are dry and not sooty - that's not your problem.
On the other hand, if it is possibly pump failure due to fuel overheating or any other fuel delivery failure, the plugs should not be sooty and will be dry. Also, you could try the "cold gas" trick. Carry a gas can with 3-5 gallons of gas. Next time it happens, dump it in. You did mention the problem first appeared at very low gas levels. This would be consistent with gas overheating. As I mentioned, 044s heat the gas more than the stock pump due to much higher output recirculating. When did you install the 044?
If the CPS fails, you get no spark, another reason to pull one of the spark plugs or use an inductive timing light on one of the wires to check for spark. Also, the tach will not bounce during start attempts.
I haven't seen a MAF failure do this. Usually the car will start and run although very poorly. When the MAF goes out of calibration, its reduced voltage signal compared to airflow leans the mixture. If it is disconnected, the LH provides a limited "limp-home" fueling mode with only a couple of RPM related injector pulse widths. You have something that seems to be progressive and heat-related. Not sure how the MAF could do that.
If you have spark after a shutdown, I would try to determine if the fueling is excessive or inadequate by some means, as I describe or otherwise. The cold gas trick would be a quick way to rule in or out the possibility overheated fuel. In some ways, what's happening fits perfectly with that, especially if you only recently installed the 044, but I just don't expect it to happen at only 3200 feet and only after 30 minutes of driving. As I described, I've only seen this actually happen in one heavily-modified 928.
On the other hand, if it is possibly pump failure due to fuel overheating or any other fuel delivery failure, the plugs should not be sooty and will be dry. Also, you could try the "cold gas" trick. Carry a gas can with 3-5 gallons of gas. Next time it happens, dump it in. You did mention the problem first appeared at very low gas levels. This would be consistent with gas overheating. As I mentioned, 044s heat the gas more than the stock pump due to much higher output recirculating. When did you install the 044?
If the CPS fails, you get no spark, another reason to pull one of the spark plugs or use an inductive timing light on one of the wires to check for spark. Also, the tach will not bounce during start attempts.
I haven't seen a MAF failure do this. Usually the car will start and run although very poorly. When the MAF goes out of calibration, its reduced voltage signal compared to airflow leans the mixture. If it is disconnected, the LH provides a limited "limp-home" fueling mode with only a couple of RPM related injector pulse widths. You have something that seems to be progressive and heat-related. Not sure how the MAF could do that.
If you have spark after a shutdown, I would try to determine if the fueling is excessive or inadequate by some means, as I describe or otherwise. The cold gas trick would be a quick way to rule in or out the possibility overheated fuel. In some ways, what's happening fits perfectly with that, especially if you only recently installed the 044, but I just don't expect it to happen at only 3200 feet and only after 30 minutes of driving. As I described, I've only seen this actually happen in one heavily-modified 928.
07-25-2012, 11:58 AM
#51
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Well, if it is temp II, there should be some evidence the car is running very rich - Sooty plugs, black sooty, smelly exhuast - when the incidents occur. The plugs will be wet if you pull any right after failed attempts to restart. If the are dry and not sooty - that's not your problem.
On the other hand, if it is possibly pump failure due to fuel overheating or any other fuel delivery failure, the plugs should not be sooty and will be dry. Also, you could try the "cold gas" trick. Carry a gas can with 3-5 gallons of gas. Next time it happens, dump it in. You did mention th problem first appeared at very low gas levels. This would be consistent with gas overheating. As I mentioned 044s heat the gas more than the stock pump due to much higher output recirculating. When did you install the 044?
On the other hand, if it is possibly pump failure due to fuel overheating or any other fuel delivery failure, the plugs should not be sooty and will be dry. Also, you could try the "cold gas" trick. Carry a gas can with 3-5 gallons of gas. Next time it happens, dump it in. You did mention th problem first appeared at very low gas levels. This would be consistent with gas overheating. As I mentioned 044s heat the gas more than the stock pump due to much higher output recirculating. When did you install the 044?
I put the 044 in back when I worked the entire car over (9 months ago, 5k miles). The gas was warm yesturday when I pulled the last 3-4 gallons out. Full tank today I have the cover off the pump, so when she dies, I will check the temp there as well.
Yesturday, when it died, in a few min I was able to get back up and running for another 10 min. The impact was less than the first time this happened, which makes me think the ckeaning for temp 2 helped some.
07-25-2012, 12:07 PM
#52
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Something new: when I turned left to hop on the freeway, it partially cut out (car had just sat 30 min while we had breakfast).
I have also rewired the fans when the belts to out the harnesses, but I cannot see how that would play here. Just adding everything I did since it ran good.
I have also rewired the fans when the belts to out the harnesses, but I cannot see how that would play here. Just adding everything I did since it ran good.
07-25-2012, 12:33 PM
#53
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Ok, died again, pump is hot, but not scorching.
Something else new, this time I also had little cutouts before she died completely.
I also pulled plug 2 (it was easy to get to and away from tragic). No issues. Clean and dry
The thing that always puzzles me is how hot these motors seem to be when used. Its no hotter than my other 89 (which is following me to phoenix, so that seems normal).
I also compared the 044 temp to the stock 88 pump and it is quite a bit hotter. Could I be vapor locking? Ill drive to the next gas station and fill her all the way back up...
Again, this did not happen on a couple trips I had with the 044 prior to the intake refresh, CPS, temp 2 and the 2 knock sensors. Nothing else is new or changes (well the thermastat as well).
Something else new, this time I also had little cutouts before she died completely.
I also pulled plug 2 (it was easy to get to and away from tragic). No issues. Clean and dry
The thing that always puzzles me is how hot these motors seem to be when used. Its no hotter than my other 89 (which is following me to phoenix, so that seems normal).
I also compared the 044 temp to the stock 88 pump and it is quite a bit hotter. Could I be vapor locking? Ill drive to the next gas station and fill her all the way back up...
Again, this did not happen on a couple trips I had with the 044 prior to the intake refresh, CPS, temp 2 and the 2 knock sensors. Nothing else is new or changes (well the thermastat as well).
Last edited by Spun; 07-25-2012 at 04:24 PM.
07-25-2012, 05:14 PM
#54
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Is the tank venting properly? If not the hose between tank and pump could be collapsing after some time?
I had a Corvette years ago that did this. The fuel line was collapsing after it ran awhile. Of course the fuel pump in the Vette is in the motor compartment so it sucks a long way as opposed to pushing like 928 pumps do.
I had a Corvette years ago that did this. The fuel line was collapsing after it ran awhile. Of course the fuel pump in the Vette is in the motor compartment so it sucks a long way as opposed to pushing like 928 pumps do.
07-25-2012, 06:15 PM
#56
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Is the tank venting properly? If not the hose between tank and pump could be collapsing after some time?
I had a Corvette years ago that did this. The fuel line was collapsing after it ran awhile. Of course the fuel pump in the Vette is in the motor compartment so it sucks a long way as opposed to pushing like 928 pumps do.
I had a Corvette years ago that did this. The fuel line was collapsing after it ran awhile. Of course the fuel pump in the Vette is in the motor compartment so it sucks a long way as opposed to pushing like 928 pumps do.
Yes. What could
07-25-2012, 08:07 PM
#57
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If the tank isn't venting, removing the gas cap should produce a "whoosh" and relieve the problem immediately until vacuum reaccumulates.
The amount of heat that come off these motors when you stop is impressive, as the coolant and air no longer circulates. At home, I always pop the hood up when I park the car so all the rubber doesn't get as badly cooked.
The pump will be very warm just from running. Based on my (limited) experience I would expect the pump to get noisier and noisier as vapor lock develops if that is the issue.
If the plugs are clean and dry after you try to restart and fail, that's at least evidence that temp II is not the primary issue.
If you can verify that you still have spark when it dies and will not start, then focus on fuel supply. If you had a fuel pressure gauge, you could rule out the pump. Then the focus might be on the injectors and verifying whether they are firing (dowel rod against the injector body as someone cranks the motor to sense the solenoid click). Since you did an intake refresh, the injectors were out. The connector leads are always suspect on these old cars and can suffer from manipulation during an intake refresh. The wires get twisted, abraided and can short inside the plug boot. Although this shouldn't be heat-related, who knows? A single, small short anywhere in the injector harness takes out all the injectors. So, checking whether they are firing would be something I would do.
The amount of heat that come off these motors when you stop is impressive, as the coolant and air no longer circulates. At home, I always pop the hood up when I park the car so all the rubber doesn't get as badly cooked.
The pump will be very warm just from running. Based on my (limited) experience I would expect the pump to get noisier and noisier as vapor lock develops if that is the issue.
If the plugs are clean and dry after you try to restart and fail, that's at least evidence that temp II is not the primary issue.
If you can verify that you still have spark when it dies and will not start, then focus on fuel supply. If you had a fuel pressure gauge, you could rule out the pump. Then the focus might be on the injectors and verifying whether they are firing (dowel rod against the injector body as someone cranks the motor to sense the solenoid click). Since you did an intake refresh, the injectors were out. The connector leads are always suspect on these old cars and can suffer from manipulation during an intake refresh. The wires get twisted, abraided and can short inside the plug boot. Although this shouldn't be heat-related, who knows? A single, small short anywhere in the injector harness takes out all the injectors. So, checking whether they are firing would be something I would do.
07-25-2012, 09:42 PM
#58
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If the tank isn't venting, removing the gas cap should produce a "whoosh" and relieve the problem immediately until vacuum reaccumulates.
The amount of heat that come off these motors when you stop is impressive, as the coolant and air no longer circulates. At home, I always pop the hood up when I park the car so all the rubber doesn't get as badly cooked.
The pump will be very warm just from running. Based on my (limited) experience I would expect the pump to get noisier and noisier as vapor lock develops if that is the issue.
If the plugs are clean and dry after you try to restart and fail, that's at least evidence that temp II is not the primary issue.
If you can verify that you still have spark when it dies and will not start, then focus on fuel supply. If you had a fuel pressure gauge, you could rule out the pump. Then the focus might be on the injectors and verifying whether they are firing (towel rod against the injector body as someone cranks the motor to sense the silent click). Since you did an intake refresh, the injectors were out. The connector leads are always suspect on these old cars and can suffer from manipulation during an intake refresh. The wires get twisted, abraided and can short inside the plug boot. Although this shouldn't be heat-related, who knows? A single, small short anywhere in the injector harness takes out all the injectors. So, checking whether they are firing would be something I would do.
The amount of heat that come off these motors when you stop is impressive, as the coolant and air no longer circulates. At home, I always pop the hood up when I park the car so all the rubber doesn't get as badly cooked.
The pump will be very warm just from running. Based on my (limited) experience I would expect the pump to get noisier and noisier as vapor lock develops if that is the issue.
If the plugs are clean and dry after you try to restart and fail, that's at least evidence that temp II is not the primary issue.
If you can verify that you still have spark when it dies and will not start, then focus on fuel supply. If you had a fuel pressure gauge, you could rule out the pump. Then the focus might be on the injectors and verifying whether they are firing (towel rod against the injector body as someone cranks the motor to sense the silent click). Since you did an intake refresh, the injectors were out. The connector leads are always suspect on these old cars and can suffer from manipulation during an intake refresh. The wires get twisted, abraided and can short inside the plug boot. Although this shouldn't be heat-related, who knows? A single, small short anywhere in the injector harness takes out all the injectors. So, checking whether they are firing would be something I would do.
I have fuel gage from roger, it goes on next.
It has to be fuel or ignition related..m. The slow demise of the RPms over time scream resistance change or press change. I killed on the vacuum leaks, so may I have exposed something else? Could the CPS cause anything like this or the Knocks?
07-29-2012, 03:27 PM
#59
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Question, O2 sensor do anything like this if its acting up? Acting like a rev limiter or choking off the car?
What adjusts the car in altitude for leaning out the fuel? Does th MAF play in this with the O2 sensor... could I be getting too lean and killing her off... just a random thought I had last night. I am down until I get her back to do anything...
What adjusts the car in altitude for leaning out the fuel? Does th MAF play in this with the O2 sensor... could I be getting too lean and killing her off... just a random thought I had last night. I am down until I get her back to do anything...
09-21-2012, 06:26 PM
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Ok, its not the MAF or the LH (thank you Rick in Phoenix for the loners).
I think I have it dow to the fuel pump relay/circuit do to the power demand of the 044 pump (which I don't need at this time anyhow).
I am going to drop in a new pump for an 88 (external only) and see if that takes care of this... I am also going to clean the relay and fuse interfaces... Anyone have a good way of doing that?
I think I have it dow to the fuel pump relay/circuit do to the power demand of the 044 pump (which I don't need at this time anyhow).
I am going to drop in a new pump for an 88 (external only) and see if that takes care of this... I am also going to clean the relay and fuse interfaces... Anyone have a good way of doing that?
