IT Guy, gearhead, dipping my toe back in the GM EFI world

[89S10_Project]

The FT232RL (TXD and RXD lines together straight to the "E" wire in the OBD1 ALDL) passes the Tunerpro comm test as long as it isn't connected to the truck. Try to test with it connected, it doesn't pass.

Can't receive any data from the ECU at all.

Same results with resistor and diode included in the harness.

I MAY have the diode backwards. I'm looking for intel on that.

[89S10_Project]

I see in this thread: http://www.gearhead-efi.com/Fuel-Inj...DL-Cable/page3

that guys are having more luck getting this to work with WinALDL first, then tweaking once it's proven.

I used WinALDL years ago (2002?) with the two-transistor cable on an old laptop with serial interface. So I'll give tht a go just to get some insight into my present issue.

As for payment for Tunerpro and so on, it's gonna happen on payday, whether or not I have to pony up money for someone to send me a built cable. I'd VASTLY prefer not to go that route, as I want this hardmounted into the truck and don't want it hanging off the front of the ALDL connector. If I can get the FT232RL unit working, I'll shrinkwrap it and tape it under the dash near my HAM power distribution and call it done.

[89S10_Project]

OK, tried with winaldl. I was getting some traffic from the truck, but no sensor data.

Also, we are back to this being unable to pass the commo Check in tunerpro.

Grr!

[sturgillbd]

Try some of the settings for the FTDI based cable in control panel, ports and look for the advanced settings. Here is a screenshot of the settings in XP. You may want to lower the USB transfer sizes and also play with the latency settings.

Hope this helps
Brian

[89S10_Project]

I've removed and reinstalled (through Dev Manager) the FTDI interface. I've updated the drivers to the ver released 6-16-16. I've rolled back same to the ver that Windows found on its own (2.6.16 vers 2.6.18, IIRC).

I am unable to get the software to recognize the interface in any capacity. I've tried adjusting the properties of the interface in Dev Man, no change.

I AM using the proper Com Port (come on, I'm an IT guy... ;) )

I have no idea why the interface passed before and now won't.

[89S10_Project]

I was just able to successfully pull data from the truck whilst it was running!

I'm ashamed to admit that it took me all of a week to get this to happen. At the same time I'm proud to admit that it took me all of a week to get this to happen.

Apparently the TXD and RXD pins must be bridged for successful test of the unit, without it being plugged into the vehicle(as has been said, plugging the unit into the vehicle will not be a successful test).

I did so, tried the FT232 unit. Worked fine. I have another unit, an FT232RL, here- tried it too, it too passed once I bridged RX to TX. This more or less proves the test process wants loopback on the chip TXD/RXD circuit. (Kinda like testing a T1 smartjack, or a POTS jack ;) )

Went to the truck, connected the FT232 unit to the harness in the vehicle. No joy. I couldn't get data with the TX and RX bridged to the ALDL "E" pin (89 S10 Blazer 7747 BTW). Tried in WinALDL and was able to get partial, though useless, data- I couldn't even get TPS volt or anything else useful. Don't care, I'm moving toward Tunerpro and ALDLdroid for my solutions.

Tried the "RXD and TXD bridged with a diode and a 1Kohm resistor) trick. No joy.

Resigned myself to spending $100+ to get a cable and a BT module overnighted (which while a good deal for it, really need to be buying tires)
On a lark, but the FT232 in.. using the resistor and diode network, no joy. Just for S&Gs, I tried the "hardwire bridged TX and RX". Looked good, I clicked "connect"..... and got an endless "connecting" indication, but never a rejection.....

OK, interesting.... I recall hearing something about signal reflection and the TX not being needed on the 160-baud ECMs anyway... so I disconnected the TX side of the bridge.... and the damned thing CONNECTED!

BS, says I... something is fooling me. I pulled up the dash, and darn if I wasn't getting full range data.
Spark advance appears to be hunting.

I wonder if maybe I screwed up and put the 4.3 injectors in the 5.7 intake...
I'm also seeing something REALLY odd. My injectors are registering 170% duty cycle.

[89S10_Project]

I'm trying to figure out how to use the software now, here's a log file after about 5 minutes of running the engine...

ECM is a 1227747 , engine is a Gen II 350 V8 Chevy smallblock. It came out of an 89 C1500 with auto. I'm running it in an 89 S10 Blazer, so just looked up a $42 mask for a C1500 5.7 auto over on Code 59.

Note the 180-200% injector duty cycle.. at idle? (perhaps I have the 4.3 injectors in?)

Note the knock sensor counts... interesting, in that the knock sensor is presently disconnected (harness repair happening tomorrow).

Note the spark map- it's sweeping, appears to be hunting.

[Six_Shooter]

Ignore the duty cycle data, that requires a patch to the bin in order to be accurate.

You haven't posted what ADX file you're using.

It's interesting that you were able to get the data to connect without the TX pin connected. It does make some sense, since the 160 baud ECMs are constantly sending out data, and the program receiving the data simply needs to find the first byte to parse the data. This is something I'll have to keep in mind if I ever play with a 160 baud ECM again.

You really need to check what the fuel pressure is, to eliminate that as a possibility. No amount of data from the ALDL connector can correct a mechanical issue that doesn't have any direct data. ;)
Juts as an anecdote to this, I have a T-bucket that currently has a 283 installed, went through two Holley Blue fuel pumps in one week, and said "Eff it, it's going EFI..." So I converted it to TBI using a '7747 (earlier this year), and while it would start and run decently when cold, the fuel pressure would fall the longer it ran and would get worse under load. No amount of data from the ECM would point me to fuel pressure, and only saw this since I have a gauge installed on the engine I can see while driving down the road.

[89S10_Project]

I have the exact opposite problem once it's hot though. It runs rough at idle, falls on its face at tip-in of throttle, then is a screamer at higher throttle settings.

Or at least it did. I forklifted the engine side of the fuel management by installing new FPR and injectors. Seems to be running better at idle now. I haven't done a drive yet however. Family just got back from vacation so it's been a busy day since I've refurbished the fuel injection.