SOLVED: familiar song...SC sat for years, won't start, running out of ideas

Thanks Ralph....

The fuel filter is new, and the injectors are new. It was the injector change that breathed life into it again. Pressure on the rail is 40 pre-start and 35ish while running.

I just did another test and I want to add to my description of having the pump the gas to keep it running....

If the revs are high enough (above 2000) it will rev normally when I press the pedal and very responsive. Anything below 2000 and it bogs before revving.

After that test I started to wonder if there is TOO MUCH fuel and that's why it's bogging and stalling at lower rpm? Is that possible? Does FPR = fuel pressure regulator?

The injectors spray as much as the ECU tells them too, correct? Is there some other system or sensor that could be telling the ECU to spray too much fuel?

It starts on it's own and WANTS to idle now, which is an improvement, but it dies within 5 seconds if I don't pump the gas even though it's trying like hell to hang on. The exhaust smells rich to me BUT I am no expert on that. Lots of moisture on the floor under the mufflers, and both mufflers are equally hot after the test. The cats have already been removed from this one.


The ECU makes assumptions; when warm, it can adjust the fuel flow a bit (something like +- 40%, but I'm not sure on that number; one of the tuners here can correct me!) but until the O2s kick in and it goes closed loop, it has to guess.

FPR == Fuel Pressure Regulator.

35psi? Is that relative to atmospheric or to the inlet line on it (the vacuum line on non-boosted applications; the one it uses to reference the engine's plenum vacuum or pressure to adjust the pressure to the appropriate level)?

*checks book* OK, 30-40 PSI while running, 35-40 when Key On Engine Off. Methinks the FPR MAY be passing too much fuel through then. If so, it may be overloading on fuel; when you open the throttle, the TPR tells the ECU "Moar fuel! We gots air INCOMING!!!" and so it enriches more, but when you release it, there's a moment when the fuel drops, but the airflow hasn't, so it runs better.

And at higher speeds, the overloading might not be as noticable. (Greg Banish's book on EFI in the intake is ... illuminating on how this can cause a problem.)

Are the injectors factory replacements? Or aftermarket? Do you have a tune for it yet?

RwP
 
The ECU makes assumptions; when warm, it can adjust the fuel flow a bit (something like +- 40%, but I'm not sure on that number; one of the tuners here can correct me!) but until the O2s kick in and it goes closed loop, it has to guess.

FPR == Fuel Pressure Regulator.

35psi? Is that relative to atmospheric or to the inlet line on it (the vacuum line on non-boosted applications; the one it uses to reference the engine's plenum vacuum or pressure to adjust the pressure to the appropriate level)?

*checks book* OK, 30-40 PSI while running, 35-40 when Key On Engine Off. Methinks the FPR MAY be passing too much fuel through then. If so, it may be overloading on fuel; when you open the throttle, the TPR tells the ECU "Moar fuel! We gots air INCOMING!!!" and so it enriches more, but when you release it, there's a moment when the fuel drops, but the airflow hasn't, so it runs better.

And at higher speeds, the overloading might not be as noticable. (Greg Banish's book on EFI in the intake is ... illuminating on how this can cause a problem.)

Are the injectors factory replacements? Or aftermarket? Do you have a tune for it yet?

RwP


The injectors are OEM aftermarket from Standard Motor Products. At the time it was all I could get my hands on. Everything else was out of stock and I wasn't going to invest the money in high performance injectors when I wasn't sure about this motor yet.

I changed the FPR in the last couple of hours but no change.

No tune on it.

It's running a LITTLE smoother and it doesn't bog as much before revving when I give it gas. It almost revs normally but I still can't maintain a steady smooth RPM at any speed. If I try to hold it around 3000 rpm it sputters and misses and the rpm slowly goes up and down quite a lot on it's own while I hold the pedal steady.
The increase in rpm when I pump the gas is smoother than it was, even sounds like a normal engine, but trying to maintain a steady speed at any rpm is hopeless and if I let it drop all the way to idle it will eventually sputter to a stall. When I start it, it starts up as you would expect for a second or two, then starts to sputter and drops rpm until it stalls. It's not an abrupt stall.

Does this site let you upload audio or video files? Maybe I could make a recording of it running. I'm sure my description is lame.
 
Good evening


You had evidence of deposits/varnish in the fuel system. You have clean fuel, replaced filter and injectors. The engine will start but strurggles to hold idle and will eventually stall without holding the throttle open. Sounds to me like there is still fuel contamination,


I would add the strongest fuel system cleaner (Berrymans Total Fuel System Cleaner) and try the following:


Inspect the throttle body plate for sticking. Clean if necessary. Check the PCV inlet hose from intake tube to the driver valve cover for security. Correct if necessary. Add 2 bottles/ containers of Berrymans Total Fuel System Cleaner. Start car. Hold throttle until RPM are 1500 for 3 minutes. Return throttle to idle. Repeat 3-5 times. If it still wants to shut off repeat the procedure but hold RPM to 2000 and then to 2500. This should clear out enough contaminates in the fuel pump sock, fuel lines and fuel injector (basket) filters. It should idle. It should be a little rough until the first road runs.


This of course assumes that no ignition and vacuum issues are present.
 
I keep hearing a voice that whispers.. "vacuum leak.. vacuum leak" :D

I know, me too! But I've checked and checked and even capped off most of the vacuum ports as suggested by.....you perhaps.

Another clarification on previous descriptions of how it runs:

If I rev it up and down, say to 3000, its smooth both up and down. If I try to hold it there, it stumbles and even backfires a LITTLE bit and the revs will drop....but if I keep the pedal steady it will try to climb again but eventually loses the fight and stalls if I don't pump/feather the gas.
 
It's a way too familiar problem lately. My 89SC 5sp ran flawlessly for over ten years and 128,000 miles after the restore. Put on a new crank sensor with the BHJ balancer in 2008 and just drove it.
It sat in a damp driveway under a waterproof cover for two winters ( I did drive it during good weather) and barely started last month so I was just barely able to drive the car up the ramps onto a trailer and get it here to Las Vegas. It acted like it was out of fuel, and at times backfired as if the plug wires were 180 degrees out of phase.... but the exhaust stream was saturated with raw gas. so it does not appear to be a fuel shortage issue.

Cam sensor and DIS are known good units borrowed from another SC, and like you, there appears to be no more inventory of new crank sensors and I've done a diligent search. I am guessing the permanent magnet in the sensor has a detrimental effect on the induction coil in the sensor when left in the magnetic field for a long time. It seems to matter where the shutter wheel stops when you shutdown the engine. If the shutter is blocking the magnetic field from the sensor's coil, then an extended period of engine inactivity does not hurt the life span of the sensor assembly; but if the shutter wheel stop in a position that leaves the coil exposed to the full force of the permanent magnet, then the sensor's coil will slowly lose its ability to generate a clean pulse signal for the ECM and result in this condition. Anyone got another theory we can toss about. I am going to check the sensor output with an oscilloscope to see what the pulse amplitude and width actually looks like and compare it to a running SC system.
dr.dave
BTW// Looking to connect with any SC owners in the Vegas area.

cheers!


Have you made any progress with yours?
 
Good evening


You had evidence of deposits/varnish in the fuel system. You have clean fuel, replaced filter and injectors. The engine will start but strurggles to hold idle and will eventually stall without holding the throttle open. Sounds to me like there is still fuel contamination,


I would add the strongest fuel system cleaner (Berrymans Total Fuel System Cleaner) and try the following:


Inspect the throttle body plate for sticking. Clean if necessary. Check the PCV inlet hose from intake tube to the driver valve cover for security. Correct if necessary. Add 2 bottles/ containers of Berrymans Total Fuel System Cleaner. Start car. Hold throttle until RPM are 1500 for 3 minutes. Return throttle to idle. Repeat 3-5 times. If it still wants to shut off repeat the procedure but hold RPM to 2000 and then to 2500. This should clear out enough contaminates in the fuel pump sock, fuel lines and fuel injector (basket) filters. It should idle. It should be a little rough until the first road runs.


This of course assumes that no ignition and vacuum issues are present.


Thank you very much for contributing. I have not revisited the fuel for a while now but anything is worth a try at this point so I'll go through the areas you mention again. The filter is new, the pump is new, and the tank was completely drained and mopped out with a towel as much as I could reach.

As per my last update on how it runs, the sputtering and backfiring while trying to hold any high rpm could be fuel quality related, although it seems hard to believe given how thoroughly I tried to clean the tank. It's definitely not a pressure issue. I've run it with the gauge on the rail and it's steady at 35.
 
Vacuum test

Ok, so I did a little vacuum test with air pressure. Hooked up an air line to the intake tube right where it drops into the manifold and put about 20lbs on it. I can hear a constant sound of air flowing, but not any hissing from a distinct place, just a general sound of air flowing like you might hear on your gas meter on your house.
I did a crude smoke test as well using just my mouth and some smoke. Saw a tiny bit of smoke escape from a couple of vacuum line fittings but very little and nothing in the area where the most sound was coming from which is the tubes and the intake. No sounds from around the intercooler, no leaks from the tube fittings as far as I can tell.

So then, not being sure whether I should hear ANYTHING or not, I did the same test on my '92 that runs like a champ and it made the same general air flowing sound that was coming from the tubes but not from any one place in particular.

So my new question is: when doing an air pressure test to find vacuum leaks, should I hear ANYTHING at all? I'm thinking yes but I'm guessing based on my '92 making the same sound, but what do I know? (Not much according to how long it's taking me to get this thing running right)

When I open the throttle plate, the air flow increases dramatically (obviously), and I know there's a small hole in the throttle plate. Is there something I should be doing to seal off that hole as well as the IAC or the EGR before doing a test like this? If I do that, THEN should I hear nothing at all if there are no vacuum leaks?
 
One other thing to try.. when you shut your 92 off, watch the vac guage and see about how long it takes to go back to center. Then try that with the 89. If its all sealed up right, the times should be close.

The next thing I can suggest is to push some of the old fuel out of the lines until you sure its getting fresh gas. Try running the pump and opening the valve at the fuel rail to let a cupful out.
 
One other thing to try.. when you shut your 92 off, watch the vac guage and see about how long it takes to go back to center. Then try that with the 89. If its all sealed up right, the times should be close.

The next thing I can suggest is to push some of the old fuel out of the lines until you sure its getting fresh gas. Try running the pump and opening the valve at the fuel rail to let a cupful out.


Thanks. Did that and both take about the same amount of time for the vacuum to return to zero. If anything, the 89 took a tiny bit longer. How conclusive is that?

As for the fuel....I've run the car quite a bit, hoping it would smooth out, so I've already ran quite a lot of fresh fuel through, and I blew out the lines and wiped out as much of the tank as I could when changing the pump and filter. Also changed the injectors and regulator if you didn't catch that earlier....so the fuel that's in the system now is all fresh....BUT perhaps I need to pump it out again and refill. When I did it the first time I only put 5 gallons of fresh fuel in it so if there was still some nasty residue hiding in the tank still, maybe I haven't diluted it enough with fresh fuel? Until now I figured if there was still some contaminants in the fuel it would run lousy, but at least it would run without constantly pumping the pedal.

K
 
Reset the computer, and ran the car again. This time I worked hard at gingerly holding it to a steady rpm. I was able to hold it at about 3500, and then about 2500. In both cases, once I was able to hold the rpm steady I listened, and man, it runs like poop. The rise in rpm when I pump the throttle seems normally smooth, but try to hold at a steady rpm and it misfires REALLY badly and as soon as I let go of the throttle it comes right back down and stalls. No real backfiring though, it should be noted.

I just wanted to post that in case there was some misunderstanding about how smoothly it runs at high rpm. It doesn't, not at all. It's as though when the throttle is open a lot there's simply enough gas pouring in to keep it running but really badly.

I did this with another '89 DIS that is known to be good. It was on my '92.

___________________________________________________________________________________
*Yes, I put an '89 DIS on my '92 when the original failed...it was only afterwards that I learned they are different between the '89 DIS and the '92 DIS, yet my '92 ran flawlessly with it....insert comments and/or explain what the difference is between the two different part #s for a nice distraction from my misery.

___________________________________________________________________________________

So to recap AGAIN, mostly for my own sanity....

- It's not the DIS
- Presumably it's not the cam sensor because I changed that too and then the tach started working again...unless a cam sensor can get 'weak' or intermittent?
- I can't swear on my life that it's not the crank sensor, but I've tried two different ones and it runs the same, and the last time I changed it I set the clearance up as carefully as I could. The only thing left now would be to take the one off the '92 and try for a third time, but I have no codes or upshift light that would indicate that the crank sensor is bad, and it DOES start fairly quickly.
- No vacuum leaks found during a pressure test, and leak down time on the '89 was actually a bit longer than the '92 which runs great.
- Fuel pressure appears to be solid at all times.
- Fuel pressure regulator changed to one from a working '89.
- New plug wires, with firing order checked umpteen times, and then again.
- New Autolite platinum plugs
- New coil (spare....am going to put the original back on)
- I've tried a computer from another '89 (auto) before with no difference.
- New injectors....which brings me to another question: Is there ANY chance there's something about these injectors that is causing this rough running? They're not Motorcraft, and the body on these ones was slightly shorter than the stock ones, but everything else about them fit as expected and SMP says they are a direct replacement for the stock injectors.


When I checked codes again after the longer run, I got two continuous codes: 29: VSS Low (no idea why it would throw a VSS code when it was never moving), and the ever-elusive 96: Fuel Pump secondary circuit failure - battery to ECA...OR...High speed fuel pump relay open.

Can someone tell me what that code 96 really means? It comes and goes, but I don't understand what it means by the secondary circuit/battery to ECA.


So there it is. Another day in paradise and no progress. Anyone got a match?

K
 
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End of an Era ?

Have you made any progress with yours?


I had to stop thinking about this for a spell and left the trickle charger on the battery for a few days so it could fully recharge.

When this "no-start" condition first happened, the car had only been sitting for a few weeks. Over the winter, I had gone out and started the car every week or so and left it running in the driveway (sometimes for an hour or more) with the heater on MAX to drive out the moisture that built up because of a tiny leak in the moonroof. It always had at least a quarter tank of 92 octane fuel and it idled nice and smooth for 1-2 hours sitting in the driveway. I even drove it to the gas station and then around town for about 15-20 miles just to give it some exercise. So the first day I had trouble getting the engine to run, I grabbed a new cam sensor that I had in my parts box and put it on. The first few minutes of cranking was still problematic , but the ignition and timing eventually seemed to resync and the motor started to run, but a bit rough, as if one cylinder was missing. I took it for a drive, stopped by the filling station to add a few gallons to the tank and returned home after about 10 miles or so. It seemed like this had solved the issue and was now running smooth again, but I was totally wrong.

The day I was scheduled to load my SC onto a car trailer behind the moving van, the car started fine and I started driving to my destination which was 20 miles away. About four miles into my drive, the car flat out stopped and refused to start again. I had to call for a tow and it was taken to the location of the moving van and trailer. Since it was already past nightfall, I let it sit until morning. Next morning, I positioned the trailer perfectly in front of the car in case I needed to use a winch to pull the car onto the trailer. But, just for the hell of it, I got in the car and cranked the motor over and it seemed like it wanted to start. Could hear a few cylinders firing, but no go. After about ten minutes of intermittent starting attempts, it fired up and I launched the car up on the trailer nearly going off the front of it. I was relieved to have gotten this far, but it only ran for about 20 seconds and then slowly fizzled out as if it was losing fuel pressure or running out of gas.

Anyway, this small success got me and the SC to Las Vegas where it now refuses to start again. I went through all these painful details to clarify how bizarre the symptoms are, and how the fault seems to come and go mysteriously. Exasperating, indeed for a car that was a daily driver for almost six years when I lived in Dana Point and commuted to San Diego. And now to find out that critical components for this engine are no longer being made, it really looks like the sundown for the Super Coupe has finally confronted us. I am now looking at a 302-V8 EFI conversion for this chassis , if I don't just dump the thing entirely.
 
Don't give up!

I had to stop thinking about this for a spell and left the trickle charger on the battery for a few days so it could fully recharge.

When this "no-start" condition first happened, the car had only been sitting for a few weeks. Over the winter, I had gone out and started the car every week or so and left it running in the driveway (sometimes for an hour or more) with the heater on MAX to drive out the moisture that built up because of a tiny leak in the moonroof. It always had at least a quarter tank of 92 octane fuel and it idled nice and smooth for 1-2 hours sitting in the driveway. I even drove it to the gas station and then around town for about 15-20 miles just to give it some exercise. So the first day I had trouble getting the engine to run, I grabbed a new cam sensor that I had in my parts box and put it on. The first few minutes of cranking was still problematic , but the ignition and timing eventually seemed to resync and the motor started to run, but a bit rough, as if one cylinder was missing. I took it for a drive, stopped by the filling station to add a few gallons to the tank and returned home after about 10 miles or so. It seemed like this had solved the issue and was now running smooth again, but I was totally wrong.

The day I was scheduled to load my SC onto a car trailer behind the moving van, the car started fine and I started driving to my destination which was 20 miles away. About four miles into my drive, the car flat out stopped and refused to start again. I had to call for a tow and it was taken to the location of the moving van and trailer. Since it was already past nightfall, I let it sit until morning. Next morning, I positioned the trailer perfectly in front of the car in case I needed to use a winch to pull the car onto the trailer. But, just for the hell of it, I got in the car and cranked the motor over and it seemed like it wanted to start. Could hear a few cylinders firing, but no go. After about ten minutes of intermittent starting attempts, it fired up and I launched the car up on the trailer nearly going off the front of it. I was relieved to have gotten this far, but it only ran for about 20 seconds and then slowly fizzled out as if it was losing fuel pressure or running out of gas.

Anyway, this small success got me and the SC to Las Vegas where it now refuses to start again. I went through all these painful details to clarify how bizarre the symptoms are, and how the fault seems to come and go mysteriously. Exasperating, indeed for a car that was a daily driver for almost six years when I lived in Dana Point and commuted to San Diego. And now to find out that critical components for this engine are no longer being made, it really looks like the sundown for the Super Coupe has finally confronted us. I am now looking at a 302-V8 EFI conversion for this chassis , if I don't just dump the thing entirely.


I had a problem with my '92 where it would die after a few minutes of running, sometimes even after 30 seconds, but then it would start again when it was cold. Turned out to be the DIS...either failing, or overheated and damaged itself. Put one on from an '89 (yes, I know, they're different...I have one for a '92 coming) and it's run almost perfect ever since. There's a SLIGHT misfire/stumble ocassionally at cruise and I'm hoping that's because the DIS is the wrong year.
FYI, the heatsink paste under the DIS hardens over time so ANYONE who hasn't put fresh paste on in the last 10 years should consider doing it before your DIS is damaged, especially if you have hot summers. It's remarkable how hot those things get on the bottom plate.

So maybe try a DIS before you scrap the 3.8 (if you haven't already). Otherwise, your description of slowly fizzling out as though out of gas is similar to what I'm experiencing, but my situation is a car that sat for 14 years with only periodic starts, and the engine was rebuilt right before it was parked so my options for a cause are numerous to say the least.
 
And now to find out that critical components for this engine are no longer being made, it really looks like the sundown for the Super Coupe has finally confronted us.
We have a big issue in front of us in that crank sensors are not longer being manufactured, at least that I know of through normal national suppliers. :( This means we either hoard, find a suitable substitute, repair what we have, or get a supplier to run a batch of sensors for us and make available to the community.
 
We have a big issue in front of us in that crank sensors are not longer being manufactured, at least that I know of through normal national suppliers. :( This means we either hoard, find a suitable substitute, repair what we have, or get a supplier to run a batch of sensors for us and make available to the community.


Too true....but Bill still has a few (used). Not cheap though. $180 shipped.

It's such a basic hall effect sensor. Someone should be able to remanufacture them in their garage, or modify one from another motor. Maybe I'll give it a go (if I ever get this '89 running) but I think I'll need a scope to get it identical to the originals.

It seems that most other parts are still available...although getting tougher on a budget. I know of a guy north of Toronto that still has a bunch of parts, but not as much as he used to and certainly not everything we look for...certainly not crank sensors. Rear ends. ECUs. Clusters. Transmissions. I got a couple of five speeds and a couple of blocks from him. He even has some complete, low mileage motors sitting there on stands.
 
RE: SC Crankshaft sensors

Does anyone have the OEM part number(s) for the crank sensors. I found a SU220 aftermarket number, which I think is Standard Ignition Products.
 
Does anyone have the OEM part number(s) for the crank sensors. I found a SU220 aftermarket number, which I think is Standard Ignition Products.


The only number I can make out on the one I have here is 9C followed by two more digits/letters that I can't quite make out. Even the Ford shop manual has a blank where the part no should be. Sorry...
 
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I saw one listed on Ebay today, used $135 and Ryan at the ThunderbirdSCshop has them listed.
 
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