Can't Pull Codes

[Nellybell]

Hey guys,

I am trying to pull codes for the KOEO test wint the little equss OBD1 scan tool. When I do, it does the relay checks but then just stops. It says it is linked to the computer with the little down arrow but no black square and no codes download. I pinned out all my self test pins and everything looks correct. If anybody has some ideas for me, I would really appreciate hearing them.

Thanks,

Ted

 

[Viperwolf1]

Try using the test light method. http://sbftech.com/index.php?PHPSESSID=503d07956e2df5bbd4152885883bf998&topic=2471.0

 

[Nellybell]

Thanks. I'll give it a shot.

 

[Nellybell]

No luck yet. Voltage goes high and stays there after relays click. Going to keep looking.

 

[Viperwolf1]

ECM got a good ground? Is or was this running previously?

 

[Nellybell]

Yes it is running and pretty well. My only real issue is that it seems to be slightly rich. I do not have a cat and I feel like that may explain the smell. I wanted to pull codes to see if I had any errors that might explain the issue. I did splice into the drivers side o2 sensor and the voltage indicated that the system was going into closed loop and dithered around maybe .4 or .5 volts. If I can't pull codes, I may try to find a wideband that I can put in to see what the AFR really is. I just don't want to toast a cat because my AFR is way too rich.

 

[Steve83]

Study these & their captions:

. .

It might help if you tell us where the EEC, wiring, & other parts came from.

 

[ransil]

read this

http://classicbroncos.com/forums/showthread.php?t=172541

 

[Nellybell]

Guys Thanks for the references. I am going to add them both to my Bronco folder.

My system is a purchased crate motor from Ford Racing Products. Basically a '93 5.0 HO with a driver's side 60 or 62 mm throttle body. The electronics are an A9P EEC purchased from Autozone. Originally I had a CW31 from FRP but it got a little wet one day. The harnesses also came from FRP. The main harness is the 12071-C302. Seems to be different from the A50 sold now. ? The engine and O2 harnesses also came from FRP. These things were apparently meant to be for Australian Ford Falcons which I think was their Mustang equivalent.

Ransil, I thought pin 30 was my issue after seeing that thread. My pin is tied to the starter relay coil +. Is that correct?

Thanks again,

Ted

 

[Ryans71]

Guys Thanks for the references. I am going to add them both to my Bronco folder.

My system is a purchased crate motor from Ford Racing Products. Basically a '93 5.0 HO with a driver's side 60 or 62 mm throttle body. The electronics are an A9P EEC purchased from Autozone. Originally I had a CW31 from FRP but it got a little wet one day. The harnesses also came from FRP. The main harness is the 12071-C302. Seems to be different from the A50 sold now. ? The engine and O2 harnesses also came from FRP. These things were apparently meant to be for Australian Ford Falcons which I think was their Mustang equivalent.

Ransil, I thought pin 30 was my issue after seeing that thread. My pin is tied to the starter relay coil +. Is that correct?

Thanks again,

Ted

Did you ever figure out why you couldn't get codes? I'm having the same issue.

Ryan

 

[Nellybell]

Ryan,

I did not. I should get back to it. Once I started to measure my O2 sensor voltages and saw I was going into closed loop, I could see the voltage waveform looked about like I thought it should. So I have just been driving it.

What setup do you have?

Ted

 

[Ryans71]

Ryan,

I did not. I should get back to it. Once I started to measure my O2 sensor voltages and saw I was going into closed loop, I could see the voltage waveform looked about like I thought it should. So I have just been driving it.

What setup do you have?

Ted

It's 89 mustang EFI on a stock 302. Have had it on there for several years with no issues. Lately the TPS had a bad spot in it so I replaced it and that fixed that issue. For the last few months now when I'm above 3K rpm and/or getting into the pedal a bit to get up a hill in second (NP435) then it starts to stumble a bit. It doesn't die, but just seems like it's not getting enough fuel.

I've got a Fram HPG1 filter in between the tank and HP pump and had a real small filter after the HP pump. Removed the filter after the pump as it seemed a little constrictive. But it still does it. I haven't checked the fuel pressure yet, but I originally replaced the fuel pump with a new bosch inline when this first started (it was a spare I had). I noticed a little up tick in power but it still stumbles in that RPM range I mentioned before. Also replaced the cap and rotor (had new extras in the garage).

Now I'm replacing the spark plugs and wires.

 

[Nellybell]

I have a '99 f250 that was missing badly under light load. Using TorquePro I could see the fuel trim on the driver's side bank start calling for more fuel as I got to 1400 rpm. I put in some injector cleaner and ran it a few miles. Checking the fuel trims showed about 50% improvement. I had one coil/plug combo on that side I hadn't changed. I put in a new coil and plug and it now runs perfect.

So applying that experience to your situation, I would be inclined to check fuel pressure, clean the injectors and check out the electrical system from coil to plug. It sounds like you have already done most of that with only the coil left. If you can find a single plug with a lean condition that might help you narrow it down some. What is your TPS resistance when closed?

I'll check into pulling codes a little today and let you know if I can get it to go.

Also there was a scanning program called TOAD that claimed to also do obd1 systems. You can still find it on ebay. I have no idea if it really works.

For about $100 dollars you can get and 8 input DAQ brick that can read the voltages from the sensors and send the info to a laptop through USB. I will probably go that route at some point.

Good luck,

Ted

 

[Ryans71]

Success!! The problem was #8 & #7 spark plugs. #8 was really bad. #8 is in the far left and #7 is to the right of it:



I guess I should change them more often. My rig is mainly a trail rig that I drive every so often. So it doesn't have much mileage on it. Those plugs have been in there for many years, but not many miles.

Ryan

 

[Nellybell]

Nice! Have you driven it since you changed em? That rig of yours looks very capable.

best regards,

Ted

 

[Ryans71]

Nice! Have you driven it since you changed em? That rig of yours looks very capable.

best regards,

Ted

I did drive it afterwards and the issue went away;D;D. Thanks.

Ryan

 

[Steve83]

That happened on Frank's '75 once, but it was a relatively new plug, and he drives it daily.