First off let me apologize if this is in the wrong section.
I don't know if it belongs under
engine
turbo
or electrical
My recently acquired 91 SS 189 kmi had no mods whatsoever,
had the CEL on when I got it.
She ran (operative word) very well, at times the CEL would go out and
it would make a bit more seat of the pants pull until it came on again.
I decided to chance it and tried the PA emission test (static test 3000 RPM and idle)
She passed no problem.
So I set out to cure the CEL blues.
Pulled the codes - ready
22 - knock sensor (is the old style)
24 -ACV (IAC?? = same thing)
35 -Purge Solenoid (which one?)
42 -Idle switch (can it be cleaned, I know it's in the TPS, will test first)
45 - Pressure exchange valve solenoid ( PEVS -- see below)
49 = Air Flow Sensor - ( sad note = dun dun - dun dun nah)
The plastic nipple on the PEVS was broken, so I glued it back on and tested the windings.
42 ohms and it passed current BUT the valve did not operate.
It passed air through both ends with and with out voltage applied.
I put it back in and while I was there plumbed a MBC valve in place of the waste gate duty solenoid.
I left the WGDS connected electrically just put the MBC in it's place in the waste gate control loop.
Took it for a spin - YIKES saw the boost run up to around 15 psi for a second or two.
Made an adjustment back to 9 psi. (I also installed a boost gauge and A/F meter at this time.
The know to be working and wired correctly A/F meter
(removed it from another turbo Subaru I own)
shows steady very low voltage -
no "tick tocking -go to full rich on boost"
like it did in the other car.
Now the problem - finally
When the SS is closed loop - - does not do this in open loop
Any time the manifold pressure goes positive - it shuts the fuel off and she fall flat on her face.
She will stall at speed if I don't leave up on the long pedal.
If I get out of it she runs fine.
So after this long diatribe
Did I put the hurt on the MAP sensor blowing 15 psi
with the PEVS in it's condition?
or
is my MAF FUBAR?
Thanks for any help.
I can't leave well enough alone
Driving with an egg under the long pedal. (UPDATED)
Moderators: Helpinators, Moderators
Driving with an egg under the long pedal. (UPDATED)
Last edited by Skip on Sat Jan 21, 2006 12:16 am, edited 1 time in total.
-
vrg3
- Vikash
- Posts: 12517
- Joined: Sun Nov 03, 2002 2:13 am
- Location: USA, OH, Cleveland (sometimes visiting DC though)
- Contact:
Code 45 makes this happen.Any time the manifold pressure goes positive - it shuts the fuel off and she fall flat on her face.
Realize that code 45 could be the pressure exchange solenoid or the pressure sensor. But if the valve doesn't click when you apply 12 volts to it, that's probably the problem. Replace the valve. The same basic valve was used in many non-turbo Imprezas and 2nd-generation Legacies. And you can use pretty much any other 3-way automotive solenoid valve too.
15 psi applied to the pressure sensor will not hurt it.
Also, your oxygen sensor may be bad.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
Clear the codes and fix the issues you know to be bad, and see what codes reappear. Then deal with them.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
Josh, thanks, after I got that list,
first thing I did was follow your instructions.
disconnected the battery for 12 hours
started it and let it idle for 10 min
took it for a short drive
checked them again - same exact list
I am sourcing here and the USMB for parts.
Vikash, thanks for the info, I will replace the PEVS with one from a Honda
I'll cut open the old one to check for proper plumbing and get the connector.
I'd like to learn more about the interaction between the MAP the MAF and the ECU when under positive
manifold pressure.
I know about the full rich map from working with L-series
but they never had a MAP
Again, this only happens in closed loop and it never did it before I monkied with
the PEVS.
I will report my findings.
I did get a new 02 sensor today.
I checked fuel mileage and I'm still getting almost 22 MPG??
Thanks again for the replies guys.
first thing I did was follow your instructions.
disconnected the battery for 12 hours
started it and let it idle for 10 min
took it for a short drive
checked them again - same exact list
I am sourcing here and the USMB for parts.
Vikash, thanks for the info, I will replace the PEVS with one from a Honda
I'll cut open the old one to check for proper plumbing and get the connector.
I'd like to learn more about the interaction between the MAP the MAF and the ECU when under positive
manifold pressure.
I know about the full rich map from working with L-series
but they never had a MAP
Again, this only happens in closed loop and it never did it before I monkied with
the PEVS.
I will report my findings.
I did get a new 02 sensor today.
I checked fuel mileage and I'm still getting almost 22 MPG??
Thanks again for the replies guys.
I don't know if I posted over on the USMB in your thread or someone elses. But with some other individuals I've helped, the canister purge solenoid can keep the codes from clearing.
I had been helping a guy over email. Had a whole bunch of codes, they wouldn't clear, he replaced the canister purge solenoid and the codes cleared.
If you hook up 12v power to the solenoid, do you hear it click?
The solenoid is under the passenger side intake manifold, and is a bitch to get at on the turbo cars.
I had been helping a guy over email. Had a whole bunch of codes, they wouldn't clear, he replaced the canister purge solenoid and the codes cleared.
If you hook up 12v power to the solenoid, do you hear it click?
The solenoid is under the passenger side intake manifold, and is a bitch to get at on the turbo cars.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
Well guys here is an update.
First I must apologize for some very poor scientific procedure.
There were so many problems and having a unusually nice day for the middle of January
well I tackled all I could, meaning I do not know for sure what fixed it.
I changed
1) the 02 sensor, put in a Bosch single wire universal, I know it will not heat up as fast (18 dollars vs 80, I'll let it heat up slower)
I put the same unit in my 93 Turbo wagon and it worked fine.
I ran a two wire cable back to the A/F gauge using one wire for the signal (white wire from the 02 sensor)
and grounded the body of the sensor via a fuel line hose clamp and ran it to a bolt near the ECU.
Used the supplied crimp connector for the sensor wire and the wire for the A/F gauge.
2) purge solenoid, Josh sure wasn't kidding when he said the are a PITA to get at.
I had to take the outlet off of the turbo just to reach the connection.
Got the connection apart and tested the solenoid - windings were open so I cut the connector off.
I mounted a solenoid from a Honda up top using the factory connector.
(if you are ever boneyarding and see a late eighties Honda,
on the firewall is a black box about 12" x 6" x 6" - it is chock full of vacuum solenoids and vacuum fittings
I got the purge solenoid and the pressure exchange valve solenoid from mine.)
3) Knock sensor, old unit had the gray plug and was typically cracked.
I ran a ground wire from the mounting bolt to the battery ground near by using 12 AWG and crimp on
eye connectors.
I use cutting wax in the socket to hold the bolt and did it all from up above through the throttle cables.
(Careful here the connector for the FI thermo sensor is right in
the path of the socket extension
and the bolt for the KS is very tight)
4) Pressure exchange solenoid vale (PEV) At Vgr3's suggestion, I used one from the Honda box. Resistance was
32 ohms close enough to the 38 called for by the FSM. Mounted it to the existing bracket
I cut the old one apart to study the plumbing path and to get the factory connector.
The shuttle was frozen preventing proper operation.
Also followed the FSM procedure for checking the MAP, used a bench power supply and my Mity Vac.
It tested just fine, again as suggested by Vikash.
Replaced all vacuum lines and secured the
MBC (plumbed in place of the wastegate solenoid) to the PEV bracket.
5) Repaired some wiring that was post toastied and looked shorted from being so close to the turbo.
As with all of these turbos that I have worked on,
the wiring and the rubber hoses are baked brittle. This wiring was for the IAC I believe.
6) Repaired atleast five vacuum line/PCV problems some by using a pipe tap and tapping the brittle rubber hoses.
I then silicone sealed the screwed in nipples and clamped what I could.
7) The hose from the coolant tank to the turbo snapped off while moving some lines, showed signs of being
glued by the PO. Again a 1/4" NPT pipe tape was a perfect fit and I had a hose barb.
I had the battery disconnected during the four hour repair. Connected it and let it idle about 10 minutes.
I then took her for a blast and now she runs like a proper SS with no CEL
I am blowing 11 to 12 psi. The A/F meter tick tocks
like it should until there is boost pressure - it then goes full rich.
Thanks again for the replies guys.
I am betting Vikash's suggestion about the PEV was the main problem.
The codes now clear no doubt to Josh's mention of
the purge solenoid winding being open.
I'll also bet I don't get 22 MPG any more.
Oh yea the muffler fell off, well the sawz-all might have had something to do with it??
Put a set of Monza chrome resonated twin slash cut tips on
a piece of straight pipe, sounds mighty fine, thank you.
Will post pictures of the new PEV, exhaust fix and purge solenoid mount if asked.
First I must apologize for some very poor scientific procedure.
There were so many problems and having a unusually nice day for the middle of January
well I tackled all I could, meaning I do not know for sure what fixed it.
I changed
1) the 02 sensor, put in a Bosch single wire universal, I know it will not heat up as fast (18 dollars vs 80, I'll let it heat up slower)
I put the same unit in my 93 Turbo wagon and it worked fine.
I ran a two wire cable back to the A/F gauge using one wire for the signal (white wire from the 02 sensor)
and grounded the body of the sensor via a fuel line hose clamp and ran it to a bolt near the ECU.
Used the supplied crimp connector for the sensor wire and the wire for the A/F gauge.
2) purge solenoid, Josh sure wasn't kidding when he said the are a PITA to get at.
I had to take the outlet off of the turbo just to reach the connection.
Got the connection apart and tested the solenoid - windings were open so I cut the connector off.
I mounted a solenoid from a Honda up top using the factory connector.
(if you are ever boneyarding and see a late eighties Honda,
on the firewall is a black box about 12" x 6" x 6" - it is chock full of vacuum solenoids and vacuum fittings
I got the purge solenoid and the pressure exchange valve solenoid from mine.)
3) Knock sensor, old unit had the gray plug and was typically cracked.
I ran a ground wire from the mounting bolt to the battery ground near by using 12 AWG and crimp on
eye connectors.
I use cutting wax in the socket to hold the bolt and did it all from up above through the throttle cables.
(Careful here the connector for the FI thermo sensor is right in
the path of the socket extension
and the bolt for the KS is very tight)
4) Pressure exchange solenoid vale (PEV) At Vgr3's suggestion, I used one from the Honda box. Resistance was
32 ohms close enough to the 38 called for by the FSM. Mounted it to the existing bracket
I cut the old one apart to study the plumbing path and to get the factory connector.
The shuttle was frozen preventing proper operation.
Also followed the FSM procedure for checking the MAP, used a bench power supply and my Mity Vac.
It tested just fine, again as suggested by Vikash.
Replaced all vacuum lines and secured the
MBC (plumbed in place of the wastegate solenoid) to the PEV bracket.
5) Repaired some wiring that was post toastied and looked shorted from being so close to the turbo.
As with all of these turbos that I have worked on,
the wiring and the rubber hoses are baked brittle. This wiring was for the IAC I believe.
6) Repaired atleast five vacuum line/PCV problems some by using a pipe tap and tapping the brittle rubber hoses.
I then silicone sealed the screwed in nipples and clamped what I could.
7) The hose from the coolant tank to the turbo snapped off while moving some lines, showed signs of being
glued by the PO. Again a 1/4" NPT pipe tape was a perfect fit and I had a hose barb.
I had the battery disconnected during the four hour repair. Connected it and let it idle about 10 minutes.
I then took her for a blast and now she runs like a proper SS with no CEL
I am blowing 11 to 12 psi. The A/F meter tick tocks
like it should until there is boost pressure - it then goes full rich.
Thanks again for the replies guys.
I am betting Vikash's suggestion about the PEV was the main problem.
The codes now clear no doubt to Josh's mention of
the purge solenoid winding being open.
I'll also bet I don't get 22 MPG any more.
Oh yea the muffler fell off, well the sawz-all might have had something to do with it??
Put a set of Monza chrome resonated twin slash cut tips on
a piece of straight pipe, sounds mighty fine, thank you.
Will post pictures of the new PEV, exhaust fix and purge solenoid mount if asked.
Last edited by Skip on Sat Jan 21, 2006 12:29 pm, edited 2 times in total.
