Engine starting to run rough.

[green57]

Gents,

I have a 85 SVO with 153,000 miles on it. Its been running fine until yesterday. It starts and runs rough but then as it warms up, it starts to run better, but not like it normally does. It has minor intermittent surges and loss of power.

It has an LA3 in it with 35 # injectors, it still has the inline intake on it with the knock sensor installed.

The codes pulled are KOEO: 54, 81, 82, 83
KOER: 24, 42, 57, 75,

I'm not worried about the 25 or 54 as I think these codes are for the missing ACT sensor, the 57 is for the neutral pressure switch, the 75 is for the break on/off or the 80's which is EGR stuff.

That leaves the 42 for the ego voltage to rich. It doesn't blow black smoke but the exhaust does have a raw gas smell to it. So I think this might be the problem. I replaced the EGO when I put the LA3 in it which was in june 2007.

Just wondering what else to check while I'm under the hood.

Thanks for any advice.

G57

[Raven855]

For an LA3 be sure to use the codes for the 87-88 turbo coupe and not the SVO. 54 is ACT out of range. 81,82,83 are BCS and IRCM and would not worry about them. On the Koer test 24 matches up to the 54 ACT. 42, the EGO, you will get for the rough running. Check your voltages, make sure the fuel is fresh, and run down the misfire before the O2 sensor. Give it a tuneup and check those plug wires first. I would disconnnect that knock sensor too.

[green57]

Started checking wires and plugs and found number two plug in this condition.

http://i1373.photobucket.com/albums/ag362/joepik1/DSC01152_zpsh7wulqvs.jpg (http://s1373.photobucket.com/user/joepik1/media/DSC01152_zpsh7wulqvs.jpg.html)

Went to the local German parts store and only noticed after I got home that they sold me AGSF32 "PM" instead of AGSF32 "C" plugs:mad:.

I've read that platinum plugs shouldn't be used, should I take them back and see if they have any "C"s in stock? I'm thinking they would have sold me "C"s if they had them, but who knows.

What are the draw backs to running a platinum plug besides the price (no wonder they were thirty dollars).

Thanks for any advice.

G57

[Raven855]

The Bosch plugs had a history of the porcelains fracturing, especially in a turbo environment. I use the NGK iridiums and like them. Nice hand guns by the way. There are quite a few of us on here that own, use, and carry.

[MikeFleming]

I've read that platinum plugs shouldn't be used, should I take them back and see if they have any "C"s in stock? I'm thinking they would have sold me "C"s if they had them, but who knows.

What are the draw backs to running a platinum plug besides the price (no wonder they were thirty dollars). That's an Old Wives Tale - about there being issues with precious metal plugs boosted engines. Ford and Chrysler are the ONLY mfgrs in the past 40 years that DID NOT use precious metal plugs OEM in in 80's era boosted engines.

Naturally, they've learned their lesson and all of their boosted engines now come with precious metal plugs.

Don;t lose any sleep over this.

BTW - your pic shows ceramic cracking due to detonation.

[Desert Patina]

For an LA3 be sure to use the codes for the 87-88 turbo coupe and not the SVO. 54 is ACT out of range. 81,82,83 are BCS and IRCM and would not worry about them. [...]

I've done extensive research on this very poorly documented subject in just the past few weeks. If my short memory serves me well enough, 82,83 are EDF, HEDF, the low and high fans that the turbocoupe has on the radiator.

I believe 81 is EGR control. The Turbocoupes use a circuit which shuts the EGR off. The SVO's use a circuit that turns the EGR on. Either way you need an EGR Control valve from a Turbocoupe, or 4cyl LTD (or Mercury equivalent) from the early 80's.

The EDF and HEDF simply ground a circuit if you want to use them with a relay to turn either two fans, or a hi/lo fan like people love from the taurus / Mk 8 / Volvo fans. I'm using a Volvo relay.

Either way only the EGR one really affects drivability assuming you have preserved the SVO fan circuit.

[green57]

Mike, good to hear about the plugs. I'll gap them and install them. Always wondered how or why that came about. If you read it on the internet, it must be true - Abraham Lincoln

Little concerned to hear that fracture was from detonation. I always pay attention for any knocking or pinging when I put my foot into it. Also thought the LA3 was more sensitive to detonation because of the acoustics of the inline intake and would pull timing sooner. I have a square intake from a 86, I guess I need to make it a priority to get it installed so everything is working as it should.

Raven855, Mustangs, helicopters, beer and guns, everybody gotta have a hobby. Although Uncle Sam picks up the tab for the helicopter, I wish the ones were a little easier on pay check.

Desert Patina, Thank you for the additional info on the codes. I have an older code reader and the section of the book doesn't differentiate the codes by model. I guess I should by a newer model. I've heard the ones now have a LCD display and show an actual number code, no more counting flashes. The EGR valve is the relay hooked to the vacuum line on the passenger side, correct?
I just finished wiring in my head light relays and I'm half way into wiring the fan to a 70 amp relay and using pin 52 from the computer to turn it on. I hope I get it right, as I'm not a wiring whiz. The head lights work and are nice and bright with the H4 bulbs in the Hella housings. I don't smell any burning wires, and haven't blown any fuses, so I think I got it right.

G57

[Raven855]

On rewiring most people increase the size of the supply wire but forget to include upgrading the ground. Don't get caught in that trap!

[Desert Patina]

Even NATO (National TurboCoupe Owners) had trouble working 82,83 out. But they are the ones who figured it out. I only confirmed it on my car. Their wiring diagram and other information is great. TBirdHeritage has a number of pages for diagnostics for LA3.

I do have a code reader that is digital. Its pretty old though. The best part is the memory function, as I always walk away from the car thinking I remember what the codes are but forget in the 10+ steps it takes to get to my computer.

IIRC, 52 is EDF and the right pin to hook it to. HEDF was 55. I think I mentioned it already, and perhaps you already saw it in the diagrams, but just in case make sure and remember that pin is the ground, not the power. I ran wires from 52 and 55 to the front of my car, and have the relay dangling with zip ties to the washer bottle cap. Its temporary while I get a hanger made either for the radiator or the battery tray.

Not that what I do should be an example for anyone else, but 25AMPS is what I run for the factory fan. The heavy duty Volvo fan is only fused for 30 AMPS, same for the Taurus that runs the same fan. 70 sounds safe to my uneducated eyes.

Oh and, yes the EGR Control Solenoid is on the fenderwell facing the passenger (through the firewall). Its source is through a check valve, and plugs into the bottom hole. The top goes to the EGR (and technically through a 'delay' according to a emissions recall notice). It has a different clip than the SVO, I believe. If you do get one, make sure and get the electrical connector also.

[green57]

New plugs installed and SVO is running normal once again. It might be running a little better because while I was working on number three and four plugs I noticed crumbly light green wire insulation on top of the valve cover. You can see it out of focus under the IAC. Did a little investigating for the source and found this.

http://i1373.photobucket.com/albums/ag362/joepik1/DSC01153_zps3d9k3uwk.jpg (http://s1373.photobucket.com/user/joepik1/media/DSC01153_zps3d9k3uwk.jpg.html)

I also noticed this when I was wiring up the head light relays. The same color of green insulation going into the voltage regulator had crumbled apart leaving bare wire exposed also requiring a replacement splice. The other colors are fine.

Took the connector apart and soldered in a new piece of wire with the pin and put the connector back together. I surprised I didn't catch it when I replaced the TPS. Hopefully this will solve the intermittent 2000 RPM high idle. Hopefully no more throttle blipping to get a normal idle.

Raven855, I found a four plug relay box from an Aerostar and wired it up using that. I used 10 gauge for the supply with a 20 amp fuse. Used 12 gauge for the lights with high temp composite plugs. I also wired a separate 12 gauge ground for each light and diodes to protect the LA3. I crimped and soldered everything. While i'm posting picts here are some.

Relay box spliced into wiring.
http://i1373.photobucket.com/albums/ag362/joepik1/DSC01070_zpsiowqoyas.jpg (http://s1373.photobucket.com/user/joepik1/media/DSC01070_zpsiowqoyas.jpg.html)

Relays and diodes plugged into relay box.
http://i1373.photobucket.com/albums/ag362/joepik1/DSC01084_zpssbnptu7a.jpg (http://s1373.photobucket.com/user/joepik1/media/DSC01084_zpssbnptu7a.jpg.html)

Factory looking installation (as much as I could make it).
http://i1373.photobucket.com/albums/ag362/joepik1/DSC01154_zpskeppvdur.jpg (http://s1373.photobucket.com/user/joepik1/media/DSC01154_zpskeppvdur.jpg.html)

[Under Pressure]

Nice job on the wiring. I like Autolite copper plugs I think the number is 744.

[Raven855]

Little concerned to hear that fracture was from detonation. I always pay attention for any knocking or pinging when I put my foot into it. Also thought the LA3 was more sensitive to detonation because of the acoustics of the inline intake and would pull timing sooner. I have a square intake from a 86, I guess I need to make it a priority to get it installed so everything is working as it should.

Raven855, Mustangs, helicopters, beer and guns, everybody gotta have a hobby. Although Uncle Sam picks up the tab for the helicopter, I wish the ones were a little easier on pay check.

G57

The LA3 does have a slightly more agressive sampling of the knock circuit according to some of the tuning forums. But it also has slightly less total advance compared to the PE computer. Which makes it a good choice today with our high mileage cars and available fuel octane and composition.

The knock sensor and placement is different between the inline and square manifold. They sample in different frequencies for their computers. You can influence their behavior tremendously with how tightly they are installed and where they are installed. They are even affected by noise from the valve train and cam, the oil you use and even the condition of the motor mounts. It's a pretty fascinating device that will pick up all kinds of different harmonics from the strangest sources!

Nice job on the wiring! Go enjoy that beer!

[Desert Patina]

From an Aerostar, for both the headlights and the fan. This is modestly awesome.

I'm interested in how you have it mounted...

[green57]

DesertPatina, The Aerostar relay box is just for the headlights, I'm still working on the fan relay which I would like to talk to you about. I would like to send you a PM about some details if you have time to answer.

I mounted the relay box to the stock mounting bracket from the Aerostar. Then I used a hot glue gun to glue the bracket to the battery. This is a temporary solution, when I get some more time (and motivation) I'm going to cut a mount out of heavy gauge sheet aluminum for the mounting bracket. Then hold everything in place with the battery hold down bolt.

G57

[Desert Patina]

Sure thing.

[MikeFleming]

I mounted the relay box to the stock mounting bracket from the Aerostar. Then I used a hot glue gun to glue the bracket to the battery. This is a temporary solution, ... Since that's not a sealed battery, I'd invest in some hermetically sealed relays.

Flipping the headlights on/off could get exciting.

[Raven855]

I took the easy approach to rewiring the fan84418442

[green57]

Raven855, That's what I was going to do, then I ran across a dual fan unit for five dollars. Figured I try and wire it to the proper pins in the LA3 "just because".

Mike, The relay box seals up pretty tight, I also made a EPP foam gasket to seal the gap where the wire loom goes into the the box.

Man, I tough that was a sealed battery. I've had it going on three or four years and haven't added a drop of water to it. Is there a difference between "maintenance free" and "sealed"? I thought they were the same thing. Had an old style battery in my HD. Had to add distilled water to it and it had a vent tube that had to be run to the bottom of the frame. It lasted about a year before I switched back to a factory sealed battery.

Is battery venting hydrogen into my engine compartment?

G57