I have the original Roch Quad and don't plan on getting rid of the ccc any time so that's not an option. I just want to know if it's possible to swap to the OBD II from OBD I with the carbed engine. I have seen plenty of posts about the TPI getting it but haven't seen any on carbs. I really want to have my tablet set up with the OBD II so I can monitor the engine while driving so it'd be nice to see how possible this is.

 

here is your new obd2 tablet.

 

hahaha are you saying the tablet programs are bad or that the OBD II won't be showing too much?

 

a ccc has basic functions to control the mc solenoid off of o2 sensor reading and ect. the ecm can control timing and retard off of the knock sensor input. you cannot use obd2 on such a primitive system.

 

well damn, I love the roch too much to get rid of it and it seems like a pain to convert to something like the edelbrock 1406 with out any ccc. thanks for the answer though.

 

what do you think an "OBD II" is?

 

well obviously the on board diagnostics, I was under the impression that it was more in depth than what the OBD I is as well as a uni size for all US cars. Instead of a more general diag on the OBD I it'll be more in depth but that's not as important. My main reason for wanting it was for the programs to tell anything from o2 readings to hp and torque at the current speed etc. I wasn't sure if it would actually work but it's worth looking into and if I'm wrong about what the OBD II is then I was wrongly informed.

 

You can monitor the ccc system just fine. It's just simpler than most newer systems and won't have as many inputs and outputs. You'll just need to fab an ALDL cable to laptop connection (you'll have to search on that one, I use an Autoxray 6000).

 

With a carb you are very limited with what you can control electronically to adjust fuel ratio so using a system like an OBD II is just a waste since you'd only be using about 1/3 of it's capabilities just to monitor engine performance

Alternatives:
If all you are worried about is A/F ratio get a wide band A/F gauge.

If you are only looking to control timing the MSD Digital Programmable 6AL-2 is a GREAT choice.

Basically on a carb'ed motor you don't have IAC controls, TPS values, and the rest can be done through gauges for engine monitoring. (oil, temp, volts, ect.) So if you're wanting to data log there are series of gauges that can tie together and do that for you.

 

I didn't think it would be that easy as just the cable, nothing seems that easy with any project I do haha. I know they make a conversion cable to OBD II output so that might work that way then.

 

I'm not all too worried about the ratios or timing the car is tuned great for our altitude and runs damn well, its just more for fun to have the gauges and all on the tablet. Keep in mind I'm a 20 year old with a sports car so there is a plethora of terrible ideas in my head and I'm just grabbing from the barrel for a winter project haha.
I thought I heard somewhere that the MSD system doesn't work very well with the Q-jet. I looked into doing the 6AL or 6AL-2 sometime last year and I kept running into people saying not to do it. I would love the rev limiter and multi shock features .

 

http://www.mafak.com/2008/08/making-...c-to-obd1.html

One such site that proposes a solution. I've no experience with it and have seen posts where users thought it was great and others where they could not get it to work.

 

My car was originally a LG4 car but I had missing parts on my carb and the secondaries would not open up due to when the choke opened up it was missing the piece that "unlocks" the secondary throttle shaft. Also the metering rods were varnished from the car sitting too long and I didn't want to mess with it.

Not recommending this to you, just what I did. I replaced the carb, and distributor with non-ecm controlled aftermarket parts and ditched the ECM. This got rid of a bunch of other stuff as well.

There are ignition options that do work with the factory systems they have to work with a computer controlled ignition system just like if it were a TPI system.

 

All the CCC system does is adjust the distributor timing and the pulse rate for the injectors on the TBIs or the solenoid in the Q-Jet. It also tells the Auto Trans when to shift. (If the CCC is not hooked to the Auto Trans, shifts don't occur until about 5 grand.) If certain parameters are NOT within spec, then the Check engine light comes on. That about it. To properly set your Q-jet you need a dwell meter to set the solenoid. There are two travel-limit screws that adjust the uppermost and lowermost travel of the solenoid. If those are OK, then ensure the dwell spec is OK. Adjust fast idle and you're set.

 

The system performs a few other functions depending on model year:

Idle bump solenoid will increase idle speed during certain ecm commanded parameters, such as deceleration

Controls AIR system and later models controlled the EVAP action.

EGR function.

85 later LG4s and earlier L69s incorporated the knock sensor into the timing control. The KS equipped systems that I've played with were unable to display timing data while the ECM was being 'read' with a scanner. I've read that the diagnostic mode disabled timing control based on KS.

The ecm only commands the torque converter lock up for the auto trans. It does not control any shift points.

I've always assumed it provided a speed reading to the cruise control module but I have never verified this.

 

If you don't have to have it dump it for a airgap and a holley.

 

the only thing the stock computer on a carbureted 80's GM car tells the trans to do is lock up the torque converter.. everything else in the trans is done with a combination of hydraulics and witchcraft.

regarding the intent of this thread: if you can get away with throwing the stock computer and all it's associated crap away, then do it. analog is the way to go. you can tell everything you need to know about the condition of the engine with a few gauges- oil pressure, water temp, voltage, and vacuum.. add in a wideband a/f ratio gauge if you want to get really picky. then it's just a matter of deciphering what those gauges are telling you, and that comes with time and experience.

 

+1 BUT the same holds true to any thirdgen 700r4 motor combo, fuel injected or carbed... I get so tired of people saying that the computer controls shifts....

 

My cruise control works and I have the electronic type speedo. At least for the early years the module for the speedo is separate from the ECM and that is what supplies the speed reading for the cruise control. On Camaros the speedo cable goes to the cruise control module and then through the firewall to the gauge.

I'm not sure about later model f-body's.

 

alright, i probably wont be ditching it just cause its not a hassle i want to deal with right now. but maybe sometime in the future i will. thanks a lot for the help.

 

I've seen TBI and EFI swap kits on Summit for older SBC's but for the price of one of those you are well on your way towards saving up for an LS1 swap.