After the OBD1 conversion in my 88si with z6 motor the check engine light will not go off. A mechanic I know said that with that conversion I am always going to have a check engine light on. I want to know if this is true? I have the P28 ECU, the right o2 sensor, injectors, and dizzy. Is he full of it or is this true?

 

wrongo, i've got an obd1 conversion and i never have check engine lights....unless of course something is wrong.

Vince

 

OT: When you do an OBD1 conversion is it possible to still use the cable VSS?

 

yep that's what i'm using...cable tranny, cable to cluster...

The reason you dont get a code is because the ecu is connected to the cluster and can monitor speeds even when you have a cable setup

Vince

 

This is going to sound stupid but all the cars I have driven were OBD0 so how do you check the codes on the OBD1 ECU? Where does the flash appear since it does not have the little window on the ECU?

 

u ground the CEL service connector pin on the obd1 ecu, then the cluster CEL will flash just like they do on a regular obd1 car.

 

There is a service connector on it.. Usally when you use a obd0-obd1 conversion harness it uses the stock one which is under the hood over by the drivers side motor mount.. It has a yellow boot over it.. Just turn your key completely off and jump the service connector with a piece of wire or a paper clip.. Then turn the key on to the run position and count the number of flashes.. Long flashes count as 10 and short ones count as 1, (ex. LONG-LONG-LONG-LONG-SHORT-SHORT is 42)..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Z6REX-SI &raquo;</TD></TR><TR><TD CLASS="quote">This is going to sound stupid but all the cars I have driven were OBD0 so how do you check the codes on the OBD1 ECU? Where does the flash appear since it does not have the little window on the ECU?</TD></TR></TABLE>

There's a 2 pin plug that you use, 88-89 there is a yellow boot sitting between the shock tower and the coolant reservoir if your car is a 90-91 the plug is near the glove box. It's just like checking timing except your CEL will flash and you'll be able to check codes. Hope this helps

 

I never knew the 90-91 was near the glove box.. Learn something new every day..

 

I have a toggle switch wired to the ecu so when i have a CEL i just pull the carpet back and flick it...that way no opening the hood and such. Either way works though

Vince

 

I don't know much about D block's or anything but I just did an obd1 on my B16.

I think don't qoute me on this, if you use the OBD1 connectors you need to disguard your resistor box, and solder them 5 wires together.

That's just my 2 cents, but maybe that's the problem and has nothing to do with anything else?

Good luck though

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crxirex &raquo;</TD></TR><TR><TD CLASS="quote">I don't know much about D block's or anything but I just did an obd1 on my B16.

I think don't qoute me on this, if you use the OBD1 connectors you need to disguard your resistor box, and solder them 5 wires together.

That's just my 2 cents, but maybe that's the problem and has nothing to do with anything else?

Good luck though</TD></TR></TABLE>

If your using the obd1 injectors.. Then yes you remove the resistor box.. If its obd0 injectors then you still need the resistor box.. Just check the resistance across each of the injectors.. If they are low impedance (2ohm-5ohm) then you need the resistor box.. If they are high impedance (10ohm-14ohm) then you dont need it.. If you dont need it you can solder the 5 wires together..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AgentJam &raquo;</TD></TR><TR><TD CLASS="quote">I have a toggle switch wired to the ecu so when i have a CEL i just pull the carpet back and flick it...that way no opening the hood and such. Either way works though

Vince</TD></TR></TABLE>

Thats what I have as well.

 

As far as i know if there obd1 you do it that way and if there obd0 leave the friggin boxy on!

I don't know my obd1 works perfect so I can't complain.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crxirex &raquo;</TD></TR><TR><TD CLASS="quote">As far as i know if there obd1 you do it that way and if there obd0 leave the friggin boxy on!

I don't know my obd1 works perfect so I can't complain.</TD></TR></TABLE>

Yours is setup correctly.. obd1 injectors with no box..