No start condition - Out of ideas

[rain_man_rich]

Im going to try my best to give background on my 1990 Loyale MFPI Turbo.  Maybe someone can help me out.

 

The symptoms are intermittent no-start conditions and chugging or no power.  This has been going on for about a year. This morning my daughter called me and said she was stuck in an intersection and the car would not start.  She also said that the car was intermittently chugging prior to stalling at the intersection.  I got her towed back to her house and once again attempted to diagnose the problem.

 

The car started when i cranked and pumped the pedal for a while.  It didn't run very well and gas vapors poured out the exhaust for a while as I gave it a good run.  It ran but it was slightly rough and did indeed chug a bit when driven hard.  I drove it back to her garage and turned it off.  Then after about 10 minutes I tried to start it again but it was no-go.  I tested the spark and it appeared to be strong.

 

The last time it did this I changed the distributor cap and it seemed to work fine.  This was a month ago.  I replaced the almost new distributor cap with a new one but the car is still in a no-start condition.

 

 Suspecting fuel might be a problem, I removed a fuel line on the downstream side of the fuel filter and when the key was turned on, the fuel had a nice heavy stream.  I have not went any further with the fuel diagnosis.

 

I've replaced the fuel filter, distributor cap, wires, and plugs. 

 

I need some suggestions to go from here. Any would be appreciated.

 

 

 

P.S. What is this? What does it do? And why is it sizzling hot when I try to start the car?

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[naru]

Not a lot to go on.

 

Hard cold starts? Hard hot starts? Both?

 

Eliminate the easy stuff first.

 

Check the coolant temp sensor for resistance and corrosion

 

Check fuel pressure.See if it holds on shut down.

Check delivery volume.My own poor starting MPFI had good pressure at idle but no volume.

 

Check compression,

 

Pictured item is the injector resistors.They should be hot.

[rain_man_rich]

Hot and cold starts are both affected but seems mostly hot.  CTS was changed about 4000 miles ago but yah it still could be that.  What are the spec limits for fuel pressure?  Checked compression numbers 110,110,110,95.

[AKghandi]

check the intake boot, from the MAF to the turbo. it sounds like its leaking, also try unplugging the MAF and see if it starts easier. it wont boost, but it should start and idle just fine

[Gloyale]

 

 

 

P.S. What is this? What does it do? And why is it sizzling hot when I try to start the car?

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That is the dropping resistor for the injectors. It's normal for it to get hot. But sizzling? Like smoking? That would be bad and indeed would cause problems ith fueling.

 

I would suggest pullimg the injector pigtails and testing each injector for a continuity. Should be about 11~13 ohms if iirc. Might want to confirm the spec but they should not be zero or infinite and should not have any continuity to ground.

 

If that's all good, I would disconnect that resistor, and test its continuity as well

[Gloyale]

 

 

 

P.S. What is this? What does it do? And why is it sizzling hot when I try to start the car?

Uploaded with ImageShack.com

That is the dropping resistor for the injectors. It's normal for it to get hot. But sizzling? Like smoking? That would be bad and indeed would cause problems ith fueling.

 

I would suggest pullimg the injector pigtails and testing each injector for a continuity. Should be about 11~13 ohms if iirc. Might want to confirm the spec but they should not be zero or infinite and should not have any continuity to ground.

 

If that's all good, I would disconnect that resistor, and test its continuity as well

[rain_man_rich]

That is the dropping resistor for the injectors. It's normal for it to get hot. But sizzling? Like smoking? That would be bad and indeed would cause problems ith fueling.

 

I would suggest pullimg the injector pigtails and testing each injector for a continuity. Should be about 11~13 ohms if iirc. Might want to confirm the spec but they should not be zero or infinite and should not have any continuity to ground.

 

If that's all good, I would disconnect that resistor, and test its continuity as well

 

 

Sizzling as in sizzled the side of my hand about a week ago.  Not smoking hot though.  I'll check the injector resistance and the resistor continuity tomorrow.  In addition, I'll pull the intake boots and check the repairs I did to them about a year ago along with the MAF disconnect.

[rain_man_rich]

Well, it's no longer in a no-start condition.  I went over to the daughter's house this morning and it fired right up and ran normally.  I decided to take it for a drive and it started acting up again when it was at operating temperature.  Cutting out at low rpm's under light and medium throttles(only sporadically).  Also, when I come to a stop it idles down and rough (again only sporadically).  I took it back to the garage to see if I could simulate the symptoms and I was able to by shifting from park to reverse and then drive over and over.  Once in a while the idle would become unstable again for a few moments then smooth back out in about 20-40 seconds.  

 

I've had similar problems to this before with dirty throttle bodies and IAC valves on other cars so I decided to give this a whirl.  I seafoamed the upper end through a vacuum line then cleaned the throttle body (which wasn't that dirty because I did it about 10,000 miles ago) and shot some seafoam creep down the IAC holes and hit the MAP with a shot of cleaner.  It seemed to have no effect and the problem persists.  At least now I can get the symptoms less randomly so maybe I can find the heart(s) of the problem.

 

While I was in there, I also checked the intake, plenum, and turbo boots but all seemed fair.

 

Researching the board I found a similar issue was solved by installing another IAC. HOWEVER,  I am perplexed at this solution because I think I have an IAC that despite my internet searches, I can't find.

 

Here is what I believe is my IAC on my car:

 

And;

 

Here is what I find on the internet from at least 5 sources (including RockAuto):

http://www.ebay.com/itm/87-94-SUBARU-IAC-IDLE-AIR-CONTROL-VALVE-AESP207-6-/150996505041

I can't seem to find this part on my throttle body anywhere....

 

After 30 minutes I gave up trying to find my IAC. 

 

Notes:

 

I did not check the resistance of the injectors because the car was running fine at one point.  I don't believe the fault lies in them.

The resistor for the fuel injectors was warm, not hot, today.  I think it only gets like that after cranking and cranking which I did not have to do today.

 

QUESTIONS:

 

Anyone know why I can't find a replacement IAC?

 

Do you suppose a faulty IAC could have anything to do with the "cutting out" I'm experiencing under light and medium throttle?  It seems to me that the IAC would have little to with this. Yes I know its unmetered air flow but it can't be that much can it?

 

How much evidence is available that I have MAF issues?  Intermittant MAF issues?

 

As always, thanks to the members of this board who find the time and are willing to part with their opinions

Edited June 20, 2013 by rain_man_rich

[AKghandi]

did you try unplugging the maf? and pulling up on the intake boot? try those and see if they change anything. if unpluggin the maf makes it start and idle normaly that could be your problem. Heres a video i did when my turbo was acting up, This was before i figured it out. it was first the intake boot then the maf

 http://www.youtube.com/watch?v=FaK6B5RHknU

Edited June 20, 2013 by AKghandi

[rain_man_rich]

AKghandi, that is very close to the idle I'm experiencing. I did unplug the MAF and it idled much worse to the point of dying.  I did check the boots and saw nowhere there was any leaking. I also ran it with the plenum off and was only able to start it once but it would not continue to run after that.

[SmashedGlass]

Possible bad injector(s)???

[naru]

Hot and cold starts are both affected but seems mostly hot.  CTS was changed about 4000 miles ago but yah it still could be that.  What are the spec limits for fuel pressure?  Checked compression numbers 110,110,110,95.

 

35 psi above manifold pressure.

So 35 w/engine off,a little lower w/idling

Pressure should hold on shut down.

 

Compression is kinda low.

I think you have a leaky injector,probably on the 95# cylinder.

Pull one or all spark plugs next time it does not start.Check for fuel fouling.Would be nice to see if it holds fuel pressure first.

 

Seems to me a faulty IAC would affect idle speed,but,not quality.

 

MPFIs have an Auxilary Air Valve rather than an ISC.It is the black square thing near the thermostat.Very simple and rarely go bad.

Item in your photo is the idle speed solenoid(for the AC) IIRC.

[Mark Humble]

One of your daughter's friends didn't happen to try to help her out and plug in the green and white connectors did they?

 

Mark

[Gloyale]

That item in your Photo is the FICD......a Fast Idle solenoid for when the A/C is on.

 

Your car DOES have an IAC, though....it's on top of the Thermostat houseing....and they can fail open.

 

But this all sounds like the classic corroded CTS.....Coolant Temp Sensor.  Located on the passenger side rear of the intake.....a bit hard to access but it's back there.  Brown 2 pin connector like the Injector connectors.  These are notoriously corroded and green and sending faulty info to the computer when warmed up.

[ivans imports]

change distributor losing conections were it plugs in or chip is going out or broken wires also check main egine harness were it plugs in that non of the pins pushed out the backside of conector or damaged

[MilesFox]

The iac would be the module on the thermostat. With your continuing symptoms, i would second the idea of corroded terminals on the CTS pigtail.

 

Also, the whole intake harness grounds to one of the manifold bolts.

 

You may want to consider cleaning/rebuilding the Throttle Position Sensor, ans the variable contacts (closed, variable, WOT) do wig out on these engines.

[AKghandi]

you know, i cant believe i didnt say this before, but check the screw on the distributor rotor. if its loose, it may cause the issues your having. just a thought. 

[Dee2]

you know, i cant believe i didnt say this before, but check the screw on the distributor rotor. if its loose, it may cause the issues your having. just a thought. 

+1

[rain_man_rich]

Will head over to the car this evening.  I'll check the set screw and clean up the CTS connection.  Also,  did Subaru give us a schrader valve to test fuel pressure?  If not, where's the appropriate connection point?

[naru]

Will head over to the car this evening.  I'll check the set screw and clean up the CTS connection.  Also,  did Subaru give us a schrader valve to test fuel pressure?  If not, where's the appropriate connection point?

No schrader valve.

Tee it in after the filter and before the fuel rail.

[rain_man_rich]

I got a chance this evening to take a look at the CTS connection. What a pain.  When I replaced the CTS, I remember that I had it all apart and it wasn't as hard to get to.  Anyways, I managed to get the connection off and it fell half apart during the process.  The metal bits looked ok but I shot it with some cleaner and put some grease on the connections and put it back on the best I could.  I also worked on the spark plug wires so they made better connections to the distributor cap as they were pretty sloppy, especially the coil wire.  

 

The car did not act up at all despite me driving it in the same manner as before.  Good news I hope.  However, when I got to the car the battery was COMPLETELY dead. I have no idea what that was all about. I charged the battery and will test it again in the morning and start tracking down a short if there is one.  

 

Where can I get a connection fitting for my CTS?

[TomRhere]

http://www.rockauto.com/catalog/x,carcode,1270099,parttype,2564

 

I would check the switch on top of the steering column. If it gets left on, it will kill the battery quickly.

[MilesFox]

FYI the connector on the CTS is the same style as the ones on the injectors. You can get a new pigtail, but i dont know where specifically, but online i'm sure.

[ivans imports]

i check feul preshure by clamping gentaly the return line and you will feel it push back or swell a bitt indacating preshure

[idosubaru]

i've worked on a zillion bad CTS connections.  when you change the connector, be sure to cut the wiring harness back and make sure the wiring isn't shot.  i've seen a couple with such bad green corroded wiring nastiness that i had to simply run new wire back to the engine harness connectors.  just figure out which pin it is and splice new wire in - sometimes much simple and avoids the issue again.

 

i have also soldered the wires directly to the CTS connetors if you don't want to mess with finding a clip on plastic connector to fit.  if it's a threaded in type CTS then you need to be able to turn it though so you solder the wire to the CTS then have a basic electrical connector on the other end so you can disconnect it.

 

CTS - soldered to wire - a few inches of wire - electrical connector..... then electrical connector on the intake manifold side to plug into.