EA81T starts then dies; video inside

[555jay]

So, this is what happens when I start it:

 

 

Starts up fine, runs for a few seconds, then stalls out. Second start I rev it up to 2k, and it stalls out right away.

 

The ECS light does not come on after either stall.

 

Compression is good, spark seems good, everything seems to be plugged in. I changed the fuel filter since this video, but the behavior is unchanged.

 

So, I'd like to compile a list of what to check/replace, preferably in order of cheapest/easiest to most difficult/expensive.

 

Thanks!

[naru]

Check that the fuel pump has voltage up to the time the engine quits rotating.

 

If OK,check fuel pressure.

[phantomD]

Had something similar with a dying/dead alternator.

[AWD TURBO!]

my bud's ford did something like that he drove all over town tuned out the cam sinner was faulty what kind of FI system does it have could it be the sinner that is under the wire cap?

[ShawnW]

I would clean the Air Flow Meter and use a spray cleaner meant for it. Parts stores do sell it but it can be hard to find.

 

CRC sells a good one. If you just replaced an air filter and it was real dirty, and a little oily, you could have a blowby issue or clogged, dirty or aftermarket PCV valve installed that caused it to become very dirty.

[555jay]

Check that the fuel pump has voltage up to the time the engine quits rotating.

 

If OK,check fuel pressure.

 

I'm not sure how to do this while the connector is attached. I stuck the probes from my multimeter into the backside of the connector, but was unable to get a signal. I'm afraid to manhandle them in there, since the plastic is almost 30 years old. Is there a finesse move for this that I don't know about?

 

Had something similar with a dying/dead alternator.

 

I disconnected the alternator and the behavior was the same. Except I couldn't start it twice.

 

I would clean the Air Flow Meter and use a spray cleaner meant for it. Parts stores do sell it but it can be hard to find.

 

CRC sells a good one. If you just replaced an air filter and it was real dirty, and a little oily, you could have a blowby issue or clogged, dirty or aftermarket PCV valve installed that caused it to become very dirty.

 

I didn't try cleaner yet, but I did disconnect the plug at the MAF, and the behavior was unchanged.

 

I took another video at the fuel pump, which is unremarkable, except that from the audio you can hear the fuel pump still trying to run just after the motor dies.

 

http://www.youtube.com/watch?v=AaopfE7pGZw

 

If anything else seems out of place, let me know. Are there any adjustments I can make from here? There's a head on one of the pressure regulators.

Edited April 11, 2011 by 555jay

[naru]

I'm not sure how to do this while the connector is attached. I stuck the probes from my multimeter into the backside of the connector, but was unable to get a signal. I'm afraid to manhandle them in there, since the plastic is almost 30 years old. Is there a finesse move for this that I don`t know about?

 

Not really,backprobe for the reading.You can check at the relay under the seat too.,but,at the pump is better.

 

I strongly suggest checking fuel pressure.

 

Make sure there is a (grey?) shielded wire attached to coil negative.W/O it,ECU sees no ignition pulses and will only run for a short time like yours does.

 

The MAF cleaning deal is more for the hotwire style,not vane type MAFs like you have.

[turbo5speedgl]

Do those use a coolant temp sensor. My car did that untill i replaced the CTS but it was an ea82t.

[ShawnW]

Yes they do. They they are very similar.

[555jay]

Not really,backprobe for the reading.You can check at the relay under the seat too.,but,at the pump is better.

 

I strongly suggest checking fuel pressure.

 

Make sure there is a (grey?) shielded wire attached to coil negative.W/O it,ECU sees no ignition pulses and will only run for a short time like yours does.

 

The MAF cleaning deal is more for the hotwire style,not vane type MAFs like you have.

 

Will pick up a pressure gauge I can install in-line and attack the connector with the probes again. What PSI will I be expecting?

 

Will take a pic of the coil so you guys can proof it for me.

 

Do those use a coolant temp sensor. My car did that untill i replaced the CTS but it was an ea82t.

Yes they do. They they are very similar.

 

This is the one screwed into the back of the radiator? Is it one I can check by disconnecting its lead?

[naru]

36 psi above manifold pressure

36 engine stopped,about 28 idling

 

I wouldn`t bother w/the meter unless pressure gauge shows something unusual.

 

Coolant temp sensor is the 2 pronged one near the thermostat.

Edited April 13, 2011 by naru
30>28

[ShawnW]

The CTS on the 84 Turbo is near the Thermostat housing if I am remembering it correctly. 2 prongs. The radiator fan switch is in the radiator.

[phantomD]

I still say it's an electrical problem with the charging system. Your car should be sitting at at least 12.5V when switched off and somewhere in the vicinity of 14V when running. The volt gauge in the video indicates something well below this.

 

A car cannot run without proper voltages running through the system, I was chasing a low idle/stalling issue for ages until I replaced the alternator for other reasons and the problem disappeared.

 

Your car is doing exactly what mine was doing in a low voltage situation, the spark may "look" good but it may not be if voltages are low, also the rest of the car (fuel pump, electronics, other electrical) need the power supply to be within specification to run properly. Disconnecting the alternator is not the right way to diagnose if it isn't charging properly, rather you should put a multimeter on the battery before, during and after starting and while revving the engine (not sure if the dash volt meters are any good on these cars). Make sure the voltages are in the ballpark of what I mentioned above, and if not, replace or fix that alternator.

Edited April 14, 2011 by phantomD

[JRD]

Had something similar with a dying/dead alternator.

 

Ditto, I just had the same problem on a naturally aspirated EA81. Result was shot alternator. Take it in and get it tested. My $.02. Good luck!

[naru]

I still say it's an electrical problem with the charging system. Your car should be sitting at at least 12.5V when switched off and somewhere in the vicinity of 14V when running. The volt gauge in the video indicates something well below this.

 

 

Voltage looks good on the 2nd higher rpm run.

[MR_Loyale]

As for checking the alternator, you can remove it and take it into Autozne where they can test it for you on a machine for free.

[phantomD]

Did you find the problem?

[555jay]

Thanks for the interest. Here are some updates:

 

Battery was bad. Was an older Optima Yellow Top, so the volts were getting low (11.8v-ish) but it could still crank all day because the amps were so high. Now replaced. Shows 12.4 - 12.6v steady.

 

 

Original alternator questionable. Tricky to make the call since I haven't had the motor running long enough to let it ramp up its charging output. Regardless, I replaced it with a refurb EA82 60amp unit. Still slow to ramp up it's output, but upon starting with throttle input, it did go up to 14v and stay there. (didn't record that, sorry.) Until the motor dies again.

 

 

Voltage at battery:

 

 

Voltage at fuel pump connector:

 

 

Coolant temp sensor is the 2 pronged one near the thermostat.

The CTS on the 84 Turbo is near the Thermostat housing if I am remembering it correctly. 2 prongs. The radiator fan switch is in the radiator.

 

Okay, this thing?

 

 

I unplugged it - no change.

I swapped it out with my spare - no change.

 

 

Will take a pic of the coil so you guys can proof it for me.

 

Tight quarters, of course. I can trace wires back as needed.

 

 

36 psi above manifold pressure

36 engine stopped,about 28 idling

 

I wouldn`t bother w/the meter unless pressure gauge shows something unusual.

 

I think I'm missing something here. How do I measure the pressure without a gauge?

[naru]

Sorry if I wasn`t clear.

I meant,I would not bother checking the fuel pump voltage unless fuel pressure gauge read low.You need a gauge.

 

The thing in your 2nd last picture is the auxilary air valve.

It opens and bypasses the throttle plate when the engine is cold for fast idle.

 

The coolant temperature sensor is right below on the left.

 

As for the coil wires,It looks like the thickish grey one is on coil - like it should be.

 

Just noticed the video.Everthing looks good there.ECU cuts off the pump AFTER the engine quits rotating.

Edited May 3, 2011 by naru
video

[555jay]

Thanks again for continued interest/support.

 

Today, I switched out this thing, which I'm reasonably sure is the coolant sensor.

 

This is the one I removed. I forgot to take a pic of the spare I put in, but of course it looked the same, just with a brassier finish. Made no difference; also no difference when the connector was just unplugged. I don't mind going to get a new one if they're known to fail.

 

I still need to pick up a can of MAF cleaner and give that a once-over.

 

Video update:

 

The first several starts show how quickly it's stalling out now; faster than before. After the 30 second mark in that video, I was giving it throttle to try and find and mimic a fast idle, but the throttle response felt delayed and inconsistent, so in the video you'll see the revs bounce all over the place while I was reacting. Still, it misses a few beats, but it doesn't stall again until I let off the throttle completely.

[Cougar]

If I remember correctly some other folks here have had a similar problem due to the MAF sensor being bad and by disconnecting it they were able to start the engine up and keep it going. You might try and see if that works for you also. Another thing you can try and see if this trouble is fuel related is to spray some starter fluid into the intake and see if you can keep the engine running by spraying small shots into the intake after the engine is going. If the engine keeps going you know the trouble is fuel related and not an ignition problem.

 

I assume you are aware that the ECU will shut down the fuel pump if it doesn't see ignition pulses coming from the ignition system. Since you aren't getting any error codes I would have to think that is ok.

[Turbone]

Has the exhaust ever been checked on this?

Like the downpipe (catalytic converter) and there may also be a mid pipe cat.

You can disconnect the DP from the turbo and run it, it wont be too loud.

This should tell you if the cats are plugged.

[555jay]

Finally got back to this after several weekends out of town.

 

I have it narrowed down to the MAF. I was able to get it running with the MAF unhooked with various lengths of the exhaust installed to check that at the same time. Final result is that with no MAF signal it idles fairly nicely at 500 RPM. It stumbled on throttle input when cold, but it ran for a full two minutes, and for the first time since I took possession, I turned off the motor with the key.

 

Without the MAF plugged in, starts fine, idles fine, ECS light stays on. As it's running I plugged in the MAF connector, the ECS light went out, and the motor dies after a few seconds.

 

I took apart the MAF to find no hot-wire like I'm used to in recent Subarus, but instead the only thing was a white plastic nipple hanging down from the top of the chamber before the flap. Is this correct, or did I miss something? Is this the correct MAF for this car? I blasted it with MAF cleaner all the same, but to no effect. What else can it try before I replace the MAF outright?

 

Thanks again for all the input!

 

 

edit: Just looked up how a vane-type MAF works. Not at all what I was thinking! LOL! So do these just go bad, then?

Edited May 29, 2011 by 555jay

[Cougar]

The MAF can go bad and I think you have proved it.

[555jay]

I picked up another MAF at the junkyard today and swapped it out. No change in behavior. :-\