1984 SVO stock boost control system not working

[Larry_S]

I removed the aftermarket boost controller and trying to get factory equipment to work as I am trying to get one of my SVOs on the selling block. When I switch the premium switch the light comes on but the boost does not change. I think it is around 12 pounds with the switch in both positions. It seems to me it should be like 9-10 and 14.

[Patrick]

Run the engine with the switch on and touch the BCS.
If you feel it clicking or vibrating, it is getting the 40HZ signal from the BCS amplifier.
If it ain't doing that, check the input signal and the output signal from the amplifier.
(I need to look up the specs. They're not handy at the moment)

Check for proper vacuum hose routing to the Boost Controller as well.

[StangSVO]

Check the fuse under the dash that is what it was on my SVO

Pat sent me the wiring diagram a couple of years ago and that is what I found.

[Patrick]

Check the fuse under the dash that is what it was on my SVO.

Dash, or was it the console? There are fuses behind the console, too.

[MikeFleming]

Here's a few pics of different angles of where that fuse [holder] is located. One through the radio opening and two from the rear of the uninstalled dash.
1753 1754 1755

You can also set the EEC-IV KOEO Self-Test into Continuous Test Mode and cycle the throttle [to WOT] to enable/disable outputs to the BCS.

[Larry_S]

You can also set the EEC-IV KOEO Self-Test into Continuous Test Mode and cycle the throttle [to WOT] to enable/disable outputs to the BCS.
Can you tell me more about this. Is the output only on during WOT? Depending on premium switch does it change duty cycle to solenoid? Does any one have a write up on how the system works and a schematic? I measured the voltage from red to yellow and it was 1.25V DC regardless of switch position. The signal was the same going to the amplifier module. But I suspect I may not have been testing anything worthwhile as car was just idling?

[Larry_S]

There is a three-wire connector at the large silver box on the front of the right front shock tower (It's cast into the box Duraspark). That is the BCM (boost control module). Unplug that 3-wire connector and see if there is +12VDC there with the ignition key on (red to black wire). If yes, the fuse and circuit are good. Move on.

Look to see that the three-wire connector is plugged into the BCM box and that the two-wire connector is connected to the BCS (boost control solenoid). If they are (or were), then run the KOEO test and check for proper cycling of the BCS.

Mike copying the above quote from other website intended to save you from having to repeat info and adding here for future search. I think I was getting 1.25 volts from red to black so I'll double check that and the fuse.

[Larry_S]

I found that I have the factory schematics for 84 SVO boost control circuit. So now I get to figure out what others have butchered the last 30 years! Yippee

[MikeFleming]

^
Ahh, the "fun" part. May the Force be With You!

The EEC-IV KOEO Self-Test Continuous Test mode happens a short time after all the slow codes are output. Then one can switch the throttle to WOT (and back) and all outputs will change state - except the injectors (some years will pulse them once when modes are switched, some will not pulse them at all during Continuous Test Mode. So if the output is off, one WOT transition will turn them, all on and vice-versa.

Do a web search on EEC IV Self-Test for details. Or get one of the manuals mentioned here (http://www.svocop.com/forum/showthread.php?841-Some-Things-For-Sale) for an introduction.

BTW - Did anyone ever get back to you on t-shirts?

[Larry_S]

^
Ahh, the "fun" part. May the Force be With You!

The EEC-IV KOEO Self-Test Continuous Test mode happens a short time after all the slow codes are output. Then one can switch the throttle to WOT (and back) and all outputs will change state - except the injectors (some years will pulse them once when modes are switched, some will not pulse them at all during Continuous Test Mode. So if the output is off, one WOT transition will turn them, all on and vice-versa.

Do a web search on EEC IV Self-Test for details. Or get one of the manuals mentioned here (http://www.svocop.com/forum/showthread.php?841-Some-Things-For-Sale) for an introduction.

BTW - Did anyone ever get back to you on t-shirts? I think you may have confused me for someone else as far as tshirts. I own the manual that you had reprinted from Ford. I'll review that and also have a EEC-IV tester so will check the owners manual for the tester as well as will search online.

[Patrick]

So you don't want a Tee Shirt?
You're banned until your next post!

[Larry_S]

The boost system is working now. At least with switch off boost is limited to the wastegate and with it on the boost went higher. The previous engine melted a piston corner I suspect due to detonation. So I am not staying in boost too long at this point as it seems the knock sensor circuit did not do it's job previously and want to make sure I do not have same condition occur. I do not have a wide band so can't check air/fuel that way but can I tell anything about health from stock O2 sensor? I am asking as I have datalogging equipment and was thinking to log the 02 sensor and throttle position or rpm. Will this help me determine if engine is performing as it should as for air/fuel and are there any other sensors I might log to tell me the health of things. Being an 84 the wiring harness has seen better days but I do not feel like spending the time and money to rebuild the harness as it seems to be running pretty well. By the way I also have a breakout box so all signals are easy to access.

[MikeFleming]

On an 84 EEC with the in-line intake, you can easily test the knock sensor circuit functionality although it may require 3.5 hands, an advance-type timing light, and a small ball-peen steel hammer, say 2 or 4oz.

Setup:
1. Get the timing light setup so you can observe the current timing value.

2. Set the throttle position to where the engine is detected by the EEC as being in Part Throttle mode (approx 2000 RPM should work if the TPS is working and adjusted properly). You can use an assortment of feeler blades between the throttle stop screw and the throttle arm to set the engine speed.

3. Observe the timing value on the front pulley with the timing light (which should be in the 30-40 BTDC range now). Note this initial value. if you have an advance type light, move the marker to where it is in the middle of the scale.

4. Now gently tap (repeatedly - about 1/4 the beat of Wipeout) on the rearmost (#4) upper intake runner. Use just enough force in the tap to kill an ant on concrete, but not enough to drive a nail into oak. (Note: It is impossible to describe how to use a hammer over the Internet!) Observe the ignition timing while and during the tapping.

5. Timing should retard rather quickly, initially 2-3 degrees then slowly continue retarding as the tapping continues. DO NOT retard it more than ten degrees as the EGT will rise quickly.

6. Continue observing the timing value after the tapping has stopped. Timing should un-retard, or re-advance, at a slower rate and eventually return back to the original value noted above in Step 3.

(NOTE: this test procedure does not work with the later square intake manifold EECs, only with the early EECs.).

That is all.

[Larry_S]

I was good until you said 1/4 the beat of Wipeout. I have no sense of a beat and I do not know that song. How many milliseconds between taps? lol The knock sensor is in fact working using your recommended test.

[MikeFleming]

I was good until you said 1/4 the beat of Wipeout. I have no sense of a beat and I do not know that song.

http://www.youtube.com/watch?v=ZuBxMCk0cco

[Patrick]

Larry, I knew EXACTLY what Mike meant, and most of the time I can't understand him at all.

Make certain to reference the Surfaris version.

[SVOC]

.

Note: It is impossible to describe how to use a hammer over the Internet!


Nominated for best quote of the week!

[Patrick]

Nominated for best quote of the week!

No need to describe to anyone here how to use a hammer. If they found this place, they already know.

[Larry_S]

Ok so boost controller is working now however it seems to take a while for boost to build up past 10 to 14 psi. Also I may be hearing detonation but I can't be sure as I am not sure what it sounds like. I hear it sounds like rocks in a can but honestly I can't tell. The exhaust is a gutted converter and that's all until next weekend. I am treading carefully as the motor in there now is replacing the last motor which melted a piston (due to detonation I assume) after a computer change. A PE was installed into an 84 and I am thinking the 84 knock sensor does not play with the PE therefore knock was not detected and the engine died. So now I have this low mile 84 and reinstalled a 84 computer. There are no codes. Would a wideband tell me the health of mixture and burn and whether what I am hearing is detonation? I assume it would. If so is there a dual purpose 02 sensor I can install in stock location to satisfy stock computer that I can also datalog while driving.


If I set the idle to 1750 with a depth gauge it will sit there for a bit and then slowly creep up to 2000. I verified the TPS voltage is staying constant. And then every so often you hear a little miss and if watching with the timing light the timing is decreased 2-3 degrees momentarily. At idle the timing is around 30 degrees and with engine at 2k it advances to over 40 degrees. The idle problem seems to come and go a bit. For a while it was sitting at 2k for quite a while and the timing was rock solid and then later it was having a hard time holding timing dropping a couple degrees momentarily and then back to 30. It seems to get better after the engine is up to temperature but even so at temperature I am not convinced it is rock solid. Sometimes it drops a couple degrees with TPS set for 2k and it seems to have the 250rpm creep from initial setting. I have had 2 IACs with same results. http://mc2.gotdns.com/photo/photo_one.php?name=50313031303831352e4d5034&dir=73766f2f38345f32412f68616e6761725f717565656e

[Larry_S]

I eluded to it in post above but if a PE is installed in an 84 with in-line intake and 84 knock sensor will the knock sensor still work? I installed a PE and tried the same test Mike mentioned above with a PE and the timing was not reduced when I tapped on intake. With the TE it worked as he said. Should the PE have worked and if it really is not working is it possible the knock sensor circuit failed on PE?

[MikeFleming]

You have a bunch of questions in there. I'll attempt to address them in order.

- Pinging, or detonation, sounds like a high-pitched (the definition of "high" varies with age) ringing noise until it gets real severe. The frequency to listen for is ~5500 Hz, or a small cymbal since we've using drummer references. The reference to sounding like a "coffee can full of rocks" is more descriptive of an early carburettered Chrysler Hemi when it attempts to idle. If you hear that kind of noise in your 2.3 OHC Ford, it's already walk time.
:runningdog:

- If it had a PE with the stock in-line intake, then the KS circuit would've over-retarded ignition timing most of the time. Resulting in excessive chamber and exhaust temps. That could certainly cause a piston to melt (fail). Additionally if it retained the 31#/Hr 84 fuel injectors, it would have been running CRITICALLY lean under all operating modes, especially with any appreciable load. More melting.

- The PE will retard the timing using the hammer test - HOWEVER you will need to tap in synchronization with the crankshaft position (which is kinda difficult). Tap when the crank is between TDC and 15 ATDC and no other time. The PE KS system is much smarter - it knows when knock cannot occur and measured background "noise" during those off-times and compares those to the on-times to determine a knock threshold.

Note that the PE is calibrated to the KS location on the square intake and will NOT work properly with the KS signature on he in-line manifold. Kinda like getting all the gain levels setup for a concert in one theater and moving to a different building and expecting to use the same mic volume levels again. Not gonna work. Unfortunately that sensitivity is part of the PE hardware and code.

In other words, you cannot easily test this.

- A wideband only would tell you the relative amount of oxygen in the exhaust gas (or whatever it's measuring). So if there is a perfect burn, it will show relative fuel/air mixture. But if there is a cylinder that is not burning it will still detect the extra oxygen and report lean.

Wideband sensors do not do well at high temps - like where arrow band sensors normally live. Ideally the wideband sensor will see between 600-950 F, whereas a narrow band will live in the 500-1500 F range. A typical installation on a turbo'd engine is 20-30 inches past the turbo outlet (downstream, before the CAT inlet where things get hot agian). You can install a wideband in the stock narrow position, but it will not live very long (10-20 hours max, I suspect).

- No dual-purpose sensors available - at a reasonable cost.

- Do not expect to see a perfect idle on the 84 models. Most likely the engine has some small air leaks in the intake side (between the VAF and the valves) and it can improve somewhat if those things are fixed, but it will never be smooth like a Ferrari v-12.

- See above on PE in 84. NOT a good idea.

[Larry_S]

Car is running decent now and boost is working fine. It takes a while to build boost however I recall this is the case with the stock boost control system. As I recall years ago I defeated the boost control solenoid connecting the input and output vacuum lines together and the boost would build sooner and quicker. I am still concerned about the overall health of systems and would monitoring timing advance and rpm while driving help? Am I able to obtain timing advance from the TFI module if I was to monitor that or will that only provide me the commanded signal and I would also need a sensor to monitor top dead center? If I need to add in a sensor for top dead center that would get beyond what I would prefer to do.

[MikeFleming]

"Looking at" timing advance while driving would be worse that trying to text yourself on three phones at the same time. at each change in load, RPM, & throttle settings timing will change. It's VERY dynamic like watching 500 stocks every tenth of a second.

You could measure the PIP signal (which happens at whatever base timing is set to, typically 10 BTDC, and measure the time, in milliseconds that the SPOUT signal occurs (note SPOUT happens BEFORE the appropriate cylinders PIP signal) then calculate according to RPM and display the value. That would be very easy to do electronically.

Naturally you'd need some experience and references on how we would want an engine's timing to vary under assorted load and timing conditions. This is where the major learning curve will be, imho.

You could just look up the timing/load/RPM graph and see what the values are for your EEC calibration. The EEC will only use those table values when the KS is not enabled. Then you'd only need a tach and voltage reading on the VAF (and to do some quick load calculations).

Alteranately you could get a QH and associated software (VERY limited support form pre-PE EECs) and measure load/timing/RPM on a laptop.

And post pretty charts and graphs for us to OOO & AHHH at. That's how I do it.

[Larry_S]

I wasn't clear but my thoughts are is there some signals I can monitor in a controlled situation in order to determine if advance is approximately where it should be or if knock sensor is active and advance is dropping. I was thinking for example I could instrument and start logging from 2-4k rpm with moderate throttle in boost.

[MikeFleming]

No, there is no simple way.

[Larry_S]

Where can I find the TE computer data and specifically the WOT table if I test with WOT from 2-4k

[MikeFleming]

That might take a bit of work. I have a copy of the binary file but do not have an accurate RDT file for it.

Give me a few days to see if anyone has something available.

[Larry_S]

You could measure the PIP signal (which happens at whatever base timing is set to, typically 10 BTDC, and measure the time, in milliseconds that the SPOUT signal occurs (note SPOUT happens BEFORE the appropriate cylinders PIP signal) then calculate according to RPM and display the value. That would be very easy to do electronically. I am thinking to use PIP signal to calculate engine RPM and then calculate the delta between the rise of PIP (10degrees) and fall of the SPOUT (coil spark command). But it sounds like you are saying the SPOUT happens first suggesting the SPOUT is one cycle behind? How is advance calculated from rpm and time between PIP and SPOUT?

[Larry_S]

Is SPOUT and PIP referenced to same ground? My data logging device has 8 single ended or 4 differential.

[Larry_S]

That might take a bit of work. I have a copy of the binary file but do not have an accurate RDT file for it.

Give me a few days to see if anyone has something available. I don't think I need this just yet. I am thinking if something is up it will be obvious. I intend to monitor advance at WOT from 2k-4k as well as monitor O2 sensor. Advance should be increasing as RPMs increase and once I can calculate advance I can post graphs and if there is an issue it should be obvious I suspect.

[MikeFleming]

Is SPOUT and PIP referenced to same ground? Yes. Battery negative.


But it sounds like you are saying the SPOUT happens first suggesting the SPOUT is one cycle behind? Well, yes. Think about it. The timing is ADVANCED from base, which is 10 BTDC - when the PIP is generated, so it would have to be BEFORE the PIP for that cylinder. Or AFTER the PIP signal from the *previous* cylinder. If the SPOUT was sent AFTER the PIP, it would always be late, like less than 10 BTDC. No?

So SPOUT is advanced by sending a specified time AFTER the previous PIP signal. Note the turbo EECs have no idea which cylinder is coming up, just that there is a PIP signal.


I don't think I need this just yet. I am thinking if something is up it will be obvious. I intend to monitor advance at WOT from 2k-4k as well as monitor O2 sensor. Advance should be increasing as RPMs increase and once I can calculate advance. I can post graphs and if there is an issue it should be obvious I suspect.

Therein lies the problem as it's MUCH more complicated than this. Refer to my previous comment:


Naturally you'd need some experience and references on how we would want an engine's timing to vary under assorted load and timing conditions. This is where the major learning curve will be, imho.
What you're referring to above is from the 60's & 70's where ignition timing was strictly tied to engine RPM (mechanical advance) and that is not how today's engines work (or more importantly the engines of the 80's).

Briefly:
We want the spark to happen to where the PEAK burning pressures occur between 5 and 15 degrees ATDC - just as the piston starts going down - where the leverage is the greatest. With all fires there is a time lag between when you light the fire and when it reaches full heat (such as lighting the grill to cook bacon for Mitch). Same thing for a fire in the fireplace. There is a time lag between when the fire is started and when it puts out it's most heat.

With the above coal and wood fires, the amount of time between initial flame and peak heat is relatively fixed - and if we don't add more fuel, a relatively fixed time when the fuel is completely spent. With an IC petrol engine, it varies with RPM, pressure in the cylinder and to a lesser degree temperature, the type of fuel and air/fuel ratio. Note with an IC petrol engine we cannot increase or decrease the burnable mix amount after the intake valve closes. That ship has sailed. Think of it as paying the VISA bill. It's due on the 15th, so you have to mail it BEFORE then.

When the pressure in the cylinder is low - meaning there is a *very* small amount of air/fuel (hereafter referred to as "stuff") to be burned, the flame travels slowly as there are great distances between the assorted molecules of stuff and it takes some time to complete burning. With more stuff to burn, the flame travels faster so the burning completes sooner. As the stuff moves around faster, more of it gets started burning by the spark, so it burns to completion faster. Higher RPM makes the stuff move around faster, so there is less time between initial and complete. As RPM increases the available time to complete burning becomes MUCH shorter. The initial flame speed - as the burning releases more heat - will increase just like the coal BBQ - as there's more heat involved, the remaining unburned portions will burn faster.

With me so far?

So higher pressures (load) decreases the distance between molecules = faster burn. Less pressure = slower burning. Higher RPM, under pressure == REALLY faster burning. High RPM & Lower pressure == not so fast burning. Also note the available time to complete the burn seriously decreases at higher RPM.

We're doing a batch process thing here: fill the cylinder with a charge of stuff, burn it, remove it, repeat. Like making cookies. Just like the fireplace except we're talking a total of 20 milliseconds to "load, fire, exhaust" then repeat, change something, repeat, ... That's 20ms at 6000 RPM. 200ms at 600 RPM.

So considering how much time (in milliseconds) is available at each specific RPM and knowing we want the peak pressures to be reached in the 5-15 degree ATDC range to push the piston down, do you see some problems with just watching the advance and looking for trends?

The exercise will be totally useless without also recording RPM, TPS, VAF and then calculating load at a minimum.

Here's the Premium Timing Table from a stock PE for 91 octane:

1797

And a modified table from my current PE/MAF/EEC-Tuner installation for 95 octane:

1794

And a chart showing the stock values for assorted turbo EECs (thanks to Chris Roth!):

http://rothfam.com/svo/reference/PEvsLA3spark.pdf

[Larry_S]

Thank you for the great write up. I was basing my thought on the assumption the TE has a timing table for WOT which does not take load into account (I am clearly a novice at this). Like the following: 1798

[Larry_S]

- Do not expect to see a perfect idle on the 84 models. Most likely the engine has some small air leaks in the intake side (between the VAF and the valves) and it can improve somewhat if those things are fixed, but it will never be smooth like a Ferrari v-12.
That's an understatement. My son and I headed into Chicago today and a 458 Italia flew by. That car sounds sweet!!!!!!!!!!

[MikeFleming]

The 458 has a 4.5L v-8 engine and comes with a 7-speed Twin-Clutch automated manual gearbox.

It's Ferrari's slowest current production car - entry level so to speak.

Yeah, they sound sweet. And the stock exhaust ones are pretty quiet until you get the loud pedal going (exhaust bypass).

[Larry_S]

The 458 has a 4.5L v-8 engine and comes with a 7-speed Twin-Clutch automated manual gearbox.

It's Ferrari's slowest current production car - entry level so to speak.

Yeah, they sound sweet. And the stock exhaust ones are pretty quiet until you get the loud pedal going (exhaust bypass). Yea a minute after I posted I realized it had a v8. Still sounded sweet! Slowest current production car you sure about that? Looks to be the fastest from the current offerings and best handling. I think they are around 250k.
Ferrari's official 0-100 km/h (62 mph) acceleration is under 3.4 seconds, while top speed is over 325 km/h (202 mph),......