Seeking knowledge. Goodwrench 350, 89 TBI injection, Surging

Greetings everyone, I am hoping some of you can help me to get this sorted out.

The Situation I have going here is this.

The base Engine is a Goodwrench crate 350 86 and prior
The injection system is stock of an 89 1500 ECU, Harness Intake and Throttle body. the ECU recieves a speed signal, but it reads double what the actual speed is.
The donor truck is a 94 s10 WITH a VCM. the VCM only reads oil PSI, and Tach readout from the Dizzy to control the Fuel pump, aswell as make the rest of the trucks electrical work.

I have 0 Vacuum leaks that I can find, I have checked all the hoses, TB gasket surface, EGR surface. The EGR Is not hooked to a working circuit, there is no vacuum supplied to the EGR solenoid, I can manually open the EGR and bog the motor at idle.

When running Warm up enrichment, it runs really well doesn't surge makes good power. as soon as it warms up it begins to surge arround 1800rmp up to 2800-3000rpm. after 3000rpm it stops surging and pulls hard.

I have ran it with out the O2 sensor connected to see if it makes a difference, there was no change in the warmed up surge. I changed the O2 out with a new Bosch unit and It didn't seem to make a difference either.

I have been running at arround 4° advance, as this is where it seems to be running best, as far as feel goes. I dont have a way to datalog yet, but I do have an Actron scanner that can do Live data.

I have been having this issue since my swap a month and a half or so, and really am trying to avoid causing damage to the engine. I do have a Carb, intake, small base HEI dizzy on deck If i cant get this sorted out, but would really like to keep the EFI setup. Unfortunately I cannot afford to buy an EBL setup at this time, Its something I have been looking into, but isn't int he financial cards any time soon.

Any help is appreciate-.

Thanks in advance


Pic of said project
http://i171.photobucket.com/albums/u...ps5oiemhgg.jpg

welcome, glad to see you found your way over here. When you say vcm are you talking about the black box under hood computer? also it would help to know what the service number of the computer you are working with (the one running your engine) and the BCC. as for datalogging you can make your own cable (if your cheap like me) or purchase one from moates.net and use tunerpro. most people on here use tunerpro and can assist you when you post up a log. chances are that goodwrench motor has different fuel requirements than what that other setup came from. I assume that the 89 was a 350 also?

Oh and take that carb and dizzy and pitch it. once you get into tuning you won't want to go back.

thanks for the speedy reply,

Yes the stock black box under the hood is still there, but It only controls the Instrument cluster, Fuel pump relay, and the ABS that doesn't work any way.

The ECU for the engine is a 7747, I don't know the BCC off hand I can look tomorrow.

I haven't been keen to the Idea of back stepping from what I already have. But Always have a backup plan, just in case. Id really like to have it tuned properly and maybe pick up a few mpg as well.


Edit, nice to see a semi familiar name.

I'm assuming that this wasn't a factory TBI truck? Have you checked fuel pressure? Too much pressure could cause problems similar to these and it's something to verify before you get started tuning anyway.

For the VSS problem, it sounds like you might have a 4000ppm signal when you need a 2000ppm. If you can find a 2000ppm output, that'd be ideal. But if you can't, maybe you can wire up a DRAC or VSSB to the same signal your VCM is getting the speed from and wire that to the ECM. I don't know for sure that that would work and someone correct me if that sounds wrong.

Yes and no on the Factory setup, It was a Factory TBI 5 speed truck, but being a 94 It has its own Engine/tranny combo VCM. It was only use with a TBI 4.3 with a 5 speed, in 94/95.

the fuel pressure holds at 11.5-12 PSI at idle and WOT. as per my fancy gauge
http://i171.photobucket.com/albums/u...pstjeo1nfc.jpg

I like the gauge location! Finding out the BCC and doing some datalogging is probably your next step. I've ran a VSS showing double the speed with a 7747 without any surging issues in the past, but it could still be worth grounding the park/neutral wire and seeing if that affects anything (provided it's a BCC for an automatic).

that 7747 should be all you need. ditch the VCM and install a DRAC/VSSB run one output to the speedo and the other to the 7747. I doubt the speedo has anything to do with the surging.

ok AKAN is the code on the chip.

Id love to ditch the VCM, but its so integrated with the rest of the truck that Its not a likely possibility yet. Once I figure out the Cruse control setup, ditch the ABS figure if the DRAC will runt he Speedo properly or not. then maybe,the VSS signal I'm pulling is after the VCM on the way to the cluster, I believe I would ahve to have 2 DRAC one for the ECM one for the Speedo.

Are you saying that you already have a DRAC?

AKAN looks like it's from an '87 with 350 and manual transmission. You might want to try something more recent. I've had some luck with ASDX. Does anyone else know a good manual trans .bin for the '7747?

The DRAC is integrated into the VCM in 94. Unfortunately I don't have a spare VCM to rip apart to play with, I wish i did though.

I wonder what else the VCM could possibly be doing for your truck. does it act like a BCM too?

Quote:

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Originally Posted by PJG1173

I wonder what else the VCM could possibly be doing for your truck. does it act like a BCM too?

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Basically it has everything in it for the brakes, old engine, and enything else that needed computer control. It's a real pain in the but.

just trying to think what the "everything else" is. my 93 has the black box on the side of the master cylinder for the RWABS. not that any of that has to do with the issue you are having. we really need to get a datalog.

you can find info for that computer as well as wiring diagrams here http://www.gearhead-efi.com/Fuel-Inj...Information-42
unfortunately AKAN is not in the bin repository as it was likely superseded with another BCC. someone on here may be able to look up what that BCC was replaced with.

I'm going to have a look for another chip from abother trUck. I have a cess to an 89 automatic with a 350 that I can grab from if needed.

no need for a different chip. once tuning begins the old one will get tossed... do you plan on getting tuning hardware or getting someone to burn and mail you a chip?

I'd like to have the stuff to do it myself. But it's going to be a while before that can happen. Our trip got canceled this year since we had to buy a new car for the girl. Sucked all the funds up quick.

http://www.moates.net/aldu1-and-cabl....html?cPath=97 need one of these to data log. or a handful of parts from radioshack...

ASDX is a 350 manual bin for the 7747 ECM. It is very well documented, and Mark and I worked on getting the ECS done and highway lean cruise patches in it.

Too bad there isn't some one locally that has the stuff I need. Hopefully I can get the cable setup this coming month, then at least get a data log for more knowledgeable people than myself to look at.

AKAN is from a 1987 5.7 with M20 (465) Manual trans if you hadn't looked it up already. I may have a 9pin serial aldl cable that I made a few years ago. If I can find it, I'll pm you and send it your way. Here is the schematic and it took about 15 mins to build. All of the parts fit inside of a 9 pin serial connector shield. Works great for 160 baud systems but not at all on 8192 baud stuff. It can only receive data, not send.

Attachment 8797

As much as I wish I could, I cannot translate that into Physical placement. Circuits have been a struggle for me since forever. Might be able to find something on Google easier for my brain to wrap around. IM pretty sure I have everything though. aside from a Serial connector, and a laptop with a serial port lol.

Quote:

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Originally Posted by sturgillbd

AKAN is from a 1987 5.7 with M20 (465) Manual trans if you hadn't looked it up already. I may have a 9pin serial aldl cable that I made a few years ago. If I can find it, I'll pm you and send it your way. Here is the schematic and it took about 15 mins to build. All of the parts fit inside of a 9 pin serial connector shield. Works great for 160 baud systems but not at all on 8192 baud stuff. It can only receive data, not send.

Attachment 8797

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the above is what similar to what I used when I made my first data log cable. worked fine on my 8625 below are pic's how it turned out. here is what I based mine off of. http://cable.invisibill.net/

Here is what I use now. Just twist the RX and TX wires together and solder to a pin. Solder the gnd wire to a pin and connect the gnd to pin A in the ALDL. Connect the RX/TX pin to the serial data (either E or M depending on the ECM) . Was less than $20 shipped when I bought one. Looks like it has increased to $14.99 now for the cable. It works great though. http://www.superdroidrobots.com/shop...i-5v-ttl/1619/
Also look at this thread. These little boards are cheap on e-bay. http://www.gearhead-efi.com/Fuel-Inj...ight=Uber+Easy

Well I should be able to get a cable to start Data logging this week. Here's hoping.

i also picked up a second 7747 ECU, with a AKAJ Memcal, Just to see if myabe it was something in the other chip. It didn't make a difference, but now I have a second ECU to fiddle with.

Ok, I finally received my cable and downloaded TunerPro. I was able to log a little over an Hours worth of data driving various conditions, town, light to light, highway, interstate. my speedometer reading is inaccurate, as it is reading double actual speed.

So here is my log file, hopefully this will help to get some of this figured out. Thank you in advance.

Well some things have changed, My old laptop died so I have finally replaced it. I have simce replaced the engine I was running with a rebuilt engine from a 92 k1500. THe specs that have changed from stock, are .030 over flattop pistons, a Melling MTC-1 cam, deridged throttle body with AFPR 13.5psi, and an Airraid throttler body spacer since it came with the engine. I have about 300 miles on it now, and it runs a hell of alot better than it did before. I'm having one issue where it will bog when hot after sitting while turned off for about 10 minutes, it cts like a map sensor, but I have only been able to catch it once while logging.

The first log i did, there were no issues on this run, it was dead cold then drove for about 20 miles, varying conditions.

The second is the only one i have so far that I was logging while the bog happened, its about 50seconds-1:54 before it levels off

If any one would like to look at them and give me any input that would be great.