Struggling with an older high-end standalone. Appealing to the hive for ideas!

I have an AE86 project that went through a period of languishing before I got excited to complete it this winter and I am so close (I drove it for a short test drive!) but now it won't run, and I am out of ideas. I figured I would ask here before chucking thousands of dollars and months of time in the trash and starting over.

The system in question is an FJO 341B. FJO sold out and closed up (Holley EFI bought the design) so support is thin to non-existent. In the plus column, I have one friendly contact with an ex-FJO employee, but he is thousands of miles away and has a busy life of his own. Second plus is that a local friend (and GRMer) has the same setup running in a similar car.

The management is all wired up, the mechanical side of things is 99.9% done, and the car had started and run on my buddy's maps. The first few test starts and first couple little drives produced a functional wideband reading. The tuning was less than ideal because his car has a single throttle body and I have ITBs, so it was rich and the car started running worse, so after my second test drive I shut it down. Now it won't start and won't get a reading from the wideband. I cleaned the plugs and wideband sensor. I tried a brand-new identical FJO wideband sensor to no avail.

It has air, fuel, and spark.

I swapped coils and ECU (alone and together) into my friends car and his car ran with my parts, but still no wideband reading at the ECU. In other words, the wideband issue follows my ECU, but my ECU seems to still be capable of running a car.

I have been over the following at least a half-dozen times each:

-Comparing my wiring to the diagram and pin outs.

-Checking all the grounds, switched power, and constant power.

-Checking my harness for continuity between the ECU and the wideband.

-Checking the harness for continuity where there shouldn't be (shorts to ground or other wires.)

-Checking all the fuses and fusible links in the car.

-Checking the settings and variables in the ECU configuration.

-Trying uploading other known good 4A-GE configs. to the ECU.

-Checking the mechanical timing, both base and cam timing.

-Checking all the sensors and inputs.

-Trying a brand new wideband sensor.

None of the above tests have turned up any apparent problems, but none of them have solved the no wideband reading or gotten the car to run again. The ECU tries to warm the sensor upon keying on, but the sensor doesn't get hot. After thirty seconds or so, the reading changes to "slow" and 30:1 or 0:1 and remains there with a little red flag like a failed sensor.

The ex-FJO guy looked at a datalog and didn't see anything aside from the non-sensing wideband. He hasn't ruled out an issue with the ECU but wants to pinpoint the cause first, and I am at a total loss for how to proceed with diagnostics. Any ideas? What have I overlooked? Without a knowledge of how the innards of the ECU works and a sealed/potted electronics, where else can I look?

If I have to give up and go shopping, I have already invested so much I want to re-use as much as possible. My FJO was state of the art ten years ago, but I am sure things have changed. The Holley Dominator is a development of my FJO, but has evolved enough it isn't going to plug in to my harness, and it is somewhere north of $2000 for just the ECU, and finding anyone that has experience with them (outside the LS1 PNP world) is tough. What's the best well-supported fully programmable option to run an ITB N/A four cylinder with sequential injection, low-impedance injectors, GM-based coils, a 60-2 crank trigger wheel, Hall effect crank and cam sensors, integrated wideband, stock Toyota TPS, the ability to do blended maps for smooth running with ITBs and big cams, and enough inputs and outputs to monitor all the usual sensors plus a few, run idle control and a few triggers? Oh yeah, data logging also! I really hate to sink more money into it and rewire AGAIN, but a non-running car doesn't do me much good, and I need time to time before good weather is upon us. One other detail, I prefer preassembled. Anything starting with soldering up my own board isn't for me.

Thanks for any ideas!

Megasquirt 3 will do all that, I doubt there is anything cheaper, also, a lot of activity on the forums for support. That depends on your definition of "fully supported"

Do you have a copy of this? http://www.fjoracing.com/downloads/341Bv2_Installation_and_User_rev_A.pdf

Yeah, I glanced at the MS3. I guess by supported I mean that there is more than one other person out there running it on a setup like mine, and that I could potentially find a professional tuner in my city familiar with it. Tech support (even informal) from the folks selling it would be a nice extra, but isn't essential.

Alfadriver, I do have that manual, and it is half-finished and was never completed. The software info is pretty well fleshed out, but doesn't contain any information about how things might go wrong, let alone what to do about problems. Even a tiny bit of brief info on diagnostics would be awesome, and a manual without entire sections just blank would be better!

You've probably done this countless times already with all your checks, but as you mention the WB issue follows the ECU. Have you checked if the ECU is sending power to the correct heater pin at all? Did you check if the WB heater worked on your buddy's car?

In reply to ae86andkp61:

You swapped the ECU into a different car, and the wideband didn't work. Just to confirm, you plugged your ECU into his harness, with his wideband, correct? If so, that seems to indicate to me that you have a fault in the ECU circuitry, right?

Also, if his car ran on your ECU after your car quit running, then there must be something else wrong with yours outside of the ECU and wideband.

You've verified you have air/fuel/spark, and you've been over the harnesses/sensors/grounds/etc. Did the cam timing get out somehow? Do you still have good compression? Checked fuel pressure? Are the plugs coming out wet with fresh gas? Soot??

Have you got or can you borrow an oscilloscope? If so, that's where I'd go next on debugging the existing ECU. Look at the crank and cam trigger outputs while cranking, see if they look sane. Look at the spark and injector outputs on the ECU, see if it's actually trying to fire or squirt anything.

As far as the wideband goes, is this a sensor with its own controller (like the AEM or Innovate products), or is it a proprietary sensor with the controller built into the ECU like a Hydra uses? If it's the former, is there any kind of sensor diagnostics available on the standalone controller? The LC-2 I use with my MS3 has a status LED on it that lights up once it's happy with the sensor. Also, if it's got its own controller then it has a simple output to the ECU -- either an analog voltage-based signal or a digital serial/CAN-bus/etc one. Both can be read with an oscilloscope with a bit of effort.

If the controller is built-in to the ECU, then you've got a harder time diagnosing it. Assuming you've checked the wiring and it's right, then you've either got a dead ECU or a dead controller circuit. Have you opened up the case on the ECU? Do you see anything burnt on the board? Any exploded/leaking capacitors? Does it smell like burned electronics?

As for replacement ECU -- I'd definitely go megasquirt. There are lots of resources for them available on the net, many pro tuners have at least some experience with them, and best of all if you really want to know what it's doing, you can download the source code and read it.

AEM Infinity ECUs are pretty popular right now, especially by professional tuners, but I'm not sure how much you want to spend.

AEM EMS-4 or MS3 will do the job.

If you want to try something bleeding-edge that's much cheaper you could look into rusEFI.

BoxheadTim wrote: Have you checked if the ECU is sending power to the correct heater pin at all? Did you check if the WB heater worked on your buddy's car?

Yes, there is power on the pin which is supposed to be powered for the wideband heater. I didn’t pull the sensor on my buddy’s car, but the readout on the monitor on the laptop was identical in behavior over time to the sensor on my car which doesn’t heat.

petegossett wrote: You swapped the ECU into a different car, and the wideband didn't work. Just to confirm, you plugged your ECU into his harness, with his wideband, correct? If so, that seems to indicate to me that you have a fault in the ECU circuitry, right? Also, if his car ran on your ECU after your car quit running, then there must be something else wrong with yours outside of the ECU and wideband. the cam timing get out somehow? Do you still have good compression? Checked fuel pressure? Are the plugs coming out wet with fresh gas? Soot??

Pete, correctamundo! I plugged my ECU into his car with his harness and sensors. I agree that it would seem like I have two issues, an ECU issue and another factor with my car. Having two problems make it tough to diagnose the X factor with my car on a non-functioning ECU.

I have checked the cam timing several times and it is fine. I haven’t tested compression with a gauge. The engine had 1000-1500 miles on it since a rebuild, but in another car with different management, and had good compression when I dropped it in this car. It ran strong when I started it, and turning it over by hand doesn't feel/sound much different from before. I have checked fuel pressure multiple times and it is right around 43psi at the rail. The plugs come out damp with gas. The car will occasionally cough, backfire, and try to run. Seat of the pants it behaves sort of like a car that is mis-timed, but I know it isn’t.

codrus wrote: Have you got or can you borrow an oscilloscope? As far as the wideband goes, is this a sensor with its own controller (like the AEM or Innovate products), or is it a proprietary sensor with the controller built into the ECU like a Hydra uses? If the controller is built-in to the ECU, then you've got a harder time diagnosing it. Assuming you've checked the wiring and it's right, then you've either got a dead ECU or a dead controller circuit. Have you opened up the case on the ECU? Do you see anything burnt on the board? Any exploded/leaking capacitors? Does it smell like burned electronics?

Codrus, I don’t have an oscilloscope. My dad used to have one before he retired, but I am 99% sure he sold it when he closed up his repair shop, and in any case he is five hours away. I can't think of anyone in my area off the top of my head who has one, but I can ask around. I might see if I can find a shop around here that has one and have the car towed there as a next step. The controller for the wideband is integrated into the ECU and it has a proprietary sensor (modified NTK.) The main thing I have to go on is what the laptop plugged into the ECU tells me on the monitor screen, which is that it attempts to heat the sensor twice, fails, and then puts up a red flag saying that the sensor is “slow” and has a value of 30:1 or 0:1 which I take to mean that there is no reading from the sensor. With the sensor out of the exhaust and the laptop plugged in and monitoring, I don't feel any heat at the sensor, and the value doesn't change when going from waving around in the open air to a rag soaked with brake cleaner, which should show a change.

I haven’t taken the case apart. I don’t think it is easy to do. I know that much of the FJO stuff is both sealed and potted, not sure what the inside of the ECU case is like. The friendly ex-FJO employee suggested that it might be possible to diagnose and/or fix the ECU, but that was his response to my frustration with an issue shortly after putting it in the car and running it for the first time. That scenario would certainly look different if I have already opened the case. He also wants me to pinpoint the external cause that created the ECU problem before talking about sending it to him, which I can’t do with my current tools and my current knowledge.

Got Spark. Got fuel. Got compression? Got timing? What's the timing light show when you're cranking it?

I think it's MS3 time.

I know absolutely nothing about stand alone control systems.

But

Dr. Hess has a major point. If you have all of those things, the spark is not happening at the right time. Get an old fashioned timing light and some way to check it manually and see what it's actually doing. I'll bet you'll be surprised.

ae86andkp61 wrote:

codrus wrote: Have you got or can you borrow an oscilloscope?

Codrus, I don’t have an oscilloscope. My dad used to have one before he retired, but I am 99% sure he sold it when he closed up his repair shop, and in any case he is five hours away. I can't think of anyone in my area off the top of my head who has one, but I can ask around. I haven’t taken the case apart. I don’t think it is easy to do. I know that much of the FJO stuff is both sealed and potted, not sure what the inside of the ECU case is like. The friendly ex-FJO employee suggested that it might be possible to diagnose and/or fix the ECU, but that was his response to my frustration with an issue shortly after putting it in the car and running it for the first time. That scenario would certainly look different if I have already opened the case. He also wants me to pinpoint the external cause that created the ECU problem before talking about sending it to him, which I can’t do with my current tools and my current knowledge.

I dunno how much you'd be willing to spend on tools to try to diagnose it, but digital oscilloscopes have become a lot less expensive these days. For $89 there's the "DSO Nano":

http://www.makershed.com/products/dso-nano-3v-oscilloscope

The biggest drawback to it is that it's only a single channel, so you can only look at one signal at a time. There are a bunch of other cheap ones mentioned in this article:

http://www.edn.com/design/test-and-measurement/4422846/Try-an-oscilloscope-for-under--200

(I've never used any of the above, so I can't comment on them other than that)

If there's power on the heater power line but it doesn't get hot , that tends to suggest the heater circuit is busted. You could try heating the sensor with a torch and see if it starts reporting values that seem reasonable.

While Occam's razor suggests that it's more likely to be a single failure causing all of the problems than to have two unrelated failures happen at the same time, it does sound unlikely that a broken wideband is the only failure in your car. For one, most ECUs I've seen will happily start with a broken WB sensor and run open loop. What does it do when you try to start it? Will it run at all, perhaps with a bit of throttle? Does it run for a few seconds and then die?

Are you using MAP, or alpha-N? I've read that ITBs can be a pain to run with MAP because there isn't a good, single vacuum source to use. Are the throttles well-synchronized? The TPS is calibrated properly, right? Do you have a single throttle body manifold you could swap on for testing purposes?

I'm the friend with the car running the other FJO. Jesse... you say the pin to heat the sensor gets power, and you say it attempts to heat it. Not knowing the internals, but it seems to me that the ground for the oxy sensor isn't working...

What about asking the ex FJO employee, IF you can ran an independent ground to the sensors ground wire and see if it warms up?

You said it is trying to run (and even with a duff wideband it should start up, even if it's not running well). Did you ever throw a set of fresh plugs at it?

I've had a bunch of issues with starting an m/c engine before - it flooded, and even though I dried out the plugs on a gas hob (don't try this at home, kids) it ran badly. New plug fixed that. One of the UK mags I still read has a column written by a pro tuner and he mentions running into this issue regularly - engine got flooded, plugs are wet, they dry them out and it still won't run. Fresh plugs, engine starts.

That said, the "dry out the plug on an open flame" has worked for me in the past and often, putting the pre-heated plugs into the engine helped it over its reluctance with starting.

My concern is that the issue may not be ECU related, you swap out the ECU and you'll end up still debugging the engine and whatever new ECU you put on there.

BoxheadTim wrote: You said it is trying to run (and even with a duff wideband it should start up, even if it's not running well). Did you ever throw a set of fresh plugs at it? I've had a bunch of issues with starting an m/c engine before - it flooded, and even though I dried out the plugs on a gas hob (don't try this at home, kids) it ran badly. New plug fixed that. One of the UK mags I still read has a column written by a pro tuner and he mentions running into this issue regularly - engine got flooded, plugs are wet, they dry them out and it still won't run. Fresh plugs, engine starts. That said, the "dry out the plug on an open flame" has worked for me in the past and often, putting the pre-heated plugs into the engine helped it over its reluctance with starting. My concern is that the issue may not be ECU related, you swap out the ECU and you'll end up still debugging the engine and whatever new ECU you put on there.

Also a very good idea. Cheap too.