Skip to main content ↑ ↓
Topic: Disconnected BCS...Slight Increase in Boost....Now what? (Read 11141 times) previous topic - next topic

Disconnected BCS...Slight Increase in Boost....Now what?

Evidently my car has been pinging forever (At least since I've owned it anyway) and I just haven't noticed until today...when several friends pointing out the marbling noise constantly happening when I accelerated.

I replaced the "Top" part (Bladder part) of the EGR valve a couple months back, so I don't think that's the problem. However, one of the check engine codes I've consistently gotten time and time again is the "EGR control circuit fault"....83?

After seafoaming the engine, and no luck with that, I'm wondering if I need to change out the EGR control Solenoid?

The pinging seems to happen anytime I go from a dead stop to acceleration, or just light acceleration while doing a consistent speed. I was doing about 25mph in the neighborhood today, for several seconds and it was constantly pinging.

Idle is about 1000-1100RPM, and timing was checked a couple months ago, and was in the standard range for stock Turbo Coupe's.
<---One must always remember to Remain cool, calm and collected when dealing with your fellow man, especially on the Internet....
-DMC24guy
[/SIZE]

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #1 –
what quality fuel and what is the boost level?
[SIGPIC][/SIGPIC]
1974 maverick lsx powered turbo car SOLD
1973 maverick Tijuana Taxi Tribute
1957 chevy LSX Turbo project (race car)
Owner of Joe Dirt Fabrication

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #2 –
I always have used 87 and the Turbo has never EVER put out more than 5-6psi...max. No boost at all when the pinging is occurring.
<---One must always remember to Remain cool, calm and collected when dealing with your fellow man, especially on the Internet....
-DMC24guy
[/SIZE]

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #3 –
Are you running premium or regular mode?

Have you tried higher octane fuel in it to see if it goes away?.

Base timing?

The timing curves on the LA ECUs are VERY aggressive.
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon-  '81 Granada GL 2dr

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #4 –
Quote from: DMC24guy;155141
I always have used 87 and the Turbo has never EVER put out more than 5-6psi...max. No boost at all when the pinging is occurring.



Are you sure it is pinging and not a exhaust leak?

5-6 psi is below the factory setting.

Could be the egr valve stuck open.
[SIGPIC][/SIGPIC]
1974 maverick lsx powered turbo car SOLD
1973 maverick Tijuana Taxi Tribute
1957 chevy LSX Turbo project (race car)
Owner of Joe Dirt Fabrication

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #5 –
Regular Mode all the time. Haven't tried Premium Brands yet....a light tight on cash if you know what I mean....

10Deg past T.D.C. is timing.

Under WOT conditions, boost gets up to a maximum of 6psi, and then it's like a limiter or something kicks in and the engine recoils and the rpms drop slightly. They'll go back up if I keep holding down the accelerator, but it's as if the engine can't handle any more. When this happens the boost gauge will slightly back off from the 6psi, and like I said, so do the RPMS. I figured that problem might be a fuel issue, and not EGR related. Can't hear any pinging while at WOT, but you never know.
<---One must always remember to Remain cool, calm and collected when dealing with your fellow man, especially on the Internet....
-DMC24guy
[/SIZE]

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #6 –
Quote from: DMC24guy;155154
Regular Mode all the time. Haven't tried Premium Brands yet....a light tight on cash if you know what I mean....

10Deg past T.D.C. is timing.

Under WOT conditions, boost gets up to a maximum of 6psi, and then it's like a limiter or something kicks in and the engine recoils and the rpms drop slightly. They'll go back up if I keep holding down the accelerator, but it's as if the engine can't handle any more. When this happens the boost gauge will slightly back off from the 6psi, and like I said, so do the RPMS. I figured that problem might be a fuel issue, and not EGR related. Can't hear any pinging while at WOT, but you never know.



are you chcking the timing with the spout unhooked? \

the reason for my concern with the egr it could be stuck open and your boost could be going out the egr tube ;)  and could cause your pinging issue
[SIGPIC][/SIGPIC]
1974 maverick lsx powered turbo car SOLD
1973 maverick Tijuana Taxi Tribute
1957 chevy LSX Turbo project (race car)
Owner of Joe Dirt Fabrication

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #7 –
How Would I check to see if the EGR is staying open?
<---One must always remember to Remain cool, calm and collected when dealing with your fellow man, especially on the Internet....
-DMC24guy
[/SIZE]

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #8 –
Quote from: DMC24guy;155158
How Would I check to see if the EGR is staying open?

easiest way is to remove it and see if it is stuck open

it has 2 bolts that hold it to the intake and one large nut that hold the tube from the exhaust inside the egr valve.
[SIGPIC][/SIGPIC]
1974 maverick lsx powered turbo car SOLD
1973 maverick Tijuana Taxi Tribute
1957 chevy LSX Turbo project (race car)
Owner of Joe Dirt Fabrication

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #9 –
Quote from: DMC24guy;155154

10Deg past T.D.C. is timing.



10* BTDC or 10*ATDC?
"Past TDC" sounds like it's ATDC, which would be retarded.  Also as asked, are you checking timing with the SPOUT connector in or out?

You should be getting at LEAST 10psi boost in Normal mode.  That is the calibration on the WGA.  You are leaking boost or the WG flapper isn't closing all the way if you aren't getting at least that.

Spend the extra  $0.10/gallon on the next fill-up for Mid-grade fuel and see if that helps.  The extra couple dollars won't kill you.
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon-  '81 Granada GL 2dr

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #10 –
Ok, Timing is good. It was at 10* BTDC....with Spout Out.

Also checked out the EGR valve with a Pressure Gauge and it held up just fine. No signs of leakage.

Checked the Vacuum line running from the EGR Control Solenoid to the EGR valve itself, and it appears to have a leak somewhere. That will be replaced today.

MOST IMPORTANTLY though....I got a 1 foot section of brand new vacuum line and hooked it directly up to the EGR Control Solenoid and turned the car on. Despite revving the engine up to 3k while in park, and 2k while In Drive, no vacuum could be felt out of this hose.

What conditions should produce vacuum out of the Control Solenoid? Did I do something wrong? Or is it broken?

If it means anything, I checked the line running from the Vacuum Tree to the EVR, and it has plenty of Vacuum. I could feel it.  However, like I said, the line that runs from the EVR to the EGR valve had no vacuum whatsoever, despite my revving the engine in park and drive.

<---One must always remember to Remain cool, calm and collected when dealing with your fellow man, especially on the Internet....
-DMC24guy
[/SIZE]

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #11 –
You're not going to get anything out of the EGR system just revving the engine.  It's going to activate at part-throttle cruise. 

The line from the solenoid to the EGR will not have any vacuum in the "test" conditions you described.

Put voltage to the solenoid and see if it works....
Long live the 4-eyes!  - '83 Tbird Turbo - '85 Marquis LTS - '86 LTD Wagon-  '81 Granada GL 2dr

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #12 –
Doesn't the EGR system only activate when the ECM is receiving input from the VSS?
One 88

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #13 –
Ok, well the EVR is good. It put out a reading of 70 OHMS, and after letting the car warm up and then putting on a new Vacuum line, there was indeed vacuum. I revved the engine and saw the EGR valve moving.

So now I'm a square one again. Don't know why I'm pinging and can't figure out where my Boost is going.
<---One must always remember to Remain cool, calm and collected when dealing with your fellow man, especially on the Internet....
-DMC24guy
[/SIZE]

Disconnected BCS...Slight Increase in Boost....Now what?

Reply #14 –
Do you have the knock sensor unplugged?
[SIGPIC][/SIGPIC]