ok so heres the deal..i installed a 350 tpi into my 91 camaro rs the motor, computer and harness is out of a 92 tras am. so the car starts and runs ruff and then the idel goes up, then back down ..after that it runs pretty smooth..so i wanted to used my freind diagnosic tool on it and when we pluged it in it said "no communication" i would like to know what would cause this..???neway we ran a jumper and got the codes manually and code 12 kept comming up does ne1 know what 12 is im not to sure........nehelp would be appricated thanks......oh yea i took the car for a ride and it seemed to run strong especially compared to the 305tbi ohh sorry i forgot 1more thing i deleted the smog and put headers on it(not sure if that has ne thing to do with code 12???)

 

bump???

 

code 12 is a code that it's working correctly...

 

did you also install a 350 knock sensor MAF sensor and the chip in the computer is it for a 350 block?

 

yea i got a new knock sensor,the computer is the one out of the t/a so thats where the chip is right??if so l,yes its one for a 350 and there is no maf b/c its speed density motor

 

will this need a chip burnt or a tune??

 

you're right, the map sensor was transferred as well right?

when you step on the gas does it feel like it shudders, or feels like it bogs down.. ? that could be a faulty EGR...

 

sometimes when i step on it it feels ok but sometimes it bogs...i should be able to use the diagnostic tool right?? i just dont undersand y it doent comunicate?

 

diagnostic tool does not work the same as it does for 95 newer with OBDII vehicles... you'll have to do some troubleshooting...

 

on the chip, no you should be fine, unless the engine you put in has had some work done on it...

 

im not sure what u mean???about not working the same as on 95 and newer.i have obd 1 and the computer and harness is out of a 92 so thats obd 1 right...shouldent it work??

 

????

 

I'm talking about the scanner... your setup is fine... the scanner I don't that it will give you the same live data that you would get from OBDII... your setup is OBDI

 

yea i gotcha there....but on the 305 the scanner worked and on the 350 it wont communicate at all....just says no communication....

 

bump??

 

I think some of the 92's went to the next generation OBD. Why on earth you are doing a swap and don't have your own access to the codes or a manual is a major A.D.D. type of thing; What are you thinking???!!!

You mention deleting the 'smog' and going for headers. does this mean you didn't re-hook up an exhaust manifold sensor?

Do you know if you had communication from your plug in ALDL port "Before" you did the switching over? If you run a SEARCH you will find there have been quite a few of us with mysterious connection issues between the ALDL and the computer with no clear answers.

Lastly; what exactly did you disconect and/or bypass when you mention smog delete? Nitro-Nicky

 

ok theres not need to be a dink!!!Neagan..i had just thought that someone who did the same thing as me might have experenced the same problem with the scanner not communicating.

i do have access to the codes and i just didnt understand why code 12 would mean nothing is wrong,why would they need to tell you nothing is wrong??

i know how to get the codes using the jumper and i found that my map sensor was faulty ,so i changed it and now the car runs very well

i had a connection with the aldl port before??it just didnt make sense why i couldent connect after the motor transplant.I check my manuel and it doesnt say anything about that problem(not that i could find anyway)

when i disconnected the smog pump 2 wires where left unplugged and i got rid of all the smog pipes when i got flowtech shorty headers.

AGAIN i will mention the car is running very well.when i changed the map sensor the throttle response was corrected.but the car did seem to be a bit sluggish so after futher investigation i found that i had a bad cat.after i corrected those to things the car is running very strong.i did bring the car to get dyno'd at a local shop and was happy with how the car ran on the dyno.the only problem i am currently having is the no communication issue.i just thought that i might bennifit from having the live data from my freinds scanner??

i may not be a mechanic but i can usually figure stuff out pretty well.When i have problems i usually search this site for data and if i cant find it i make my own post.i didnt see anything about this no communication issue i am having so i made a post...i have had a few other problems and people have help me without being jerks.

 

What? I'm a 'Dink' & a 'Jerk' because I poked fun at you for not knowing what the definition of Code:12?? 'If' you really did have a manual, you would have been able to look it up right then and there; PLUS; doing a 'SEARCH' for a code '12' will tell you what you need to know. So I gather that I managed to kick you while you where down and frustrated and not quite ready for some joking around; My-Bad.

I'm currently one of the sufferers from the 'No Connection' issue between the ALDL port and the car's computer. I'm just now coming back to my project after a year's interlude & working on a couple early WW2 army trucks and need to deal with my issue of the same. So let's see if anything that I discovered last year will be of help to you now.

I have a couple hand held test & reading devices and the following was my experience. One unit always says that there's no connection, even though I disconnected and physically buffed every male/female connector between the hand-held and on down to the ECU. The 2nd, more expensive unit initially stated no connection but after I sanded all of those connections it will now sometimes intermittently work, but not long enough to run a complete diagnostic session.

I then drove my Iroc down to a local GM performance repair shop that did the initial SMOG and sellers tune-up, had them plug their diagnostic machine in and it reads out of the ALDL port beautifully. So this is good news and bad news.

My next step is to get ahold of a known working 1988 ECU with factory PROM and see if my handhelds will read off of that one. The reason I state 'Factory PROM', is that there is some debate that it's possible that one or more of the aftermarket PROM makers might have some way of defeating a handheld device from reading their PROM??? Do you know the background history of current PROM you're using?

If you dyno'd the current set-up, did they plug into the ALDL port at that time?

The question(s) I asked about the smog disconnect has more to do with not having things such as the O2 sensor and the Cold Air Temp being disconnected. Items like these will really throw things off. Many of these 3rd Gen's will run like complete crap and not have one code thrown. These early computers run super slow and a sensor has to have a visual wooden stake thru the heart before it'll actually trip a code. That's why many of the long term owners eventually learn to read what the PROM is actually telling them. In fact, the ECU thinks so slowly, that if you change the Delco O2 sensor over to a high quality Bosch unit, the Bosch sensor sends the information loop so fast that it actually confuses the ECU.

Sorry for it seeming like I was being an unhelpful smartash, but can you see how when someone asks what a code 12 is, it 'just might' seem like they don't have the manual??? I surely didn't mean to poke you in a sore spot.

In 1990 GM switched the ECM system from the very forgiving MAF system, that would work, adjust, and deal with fluctuating fuel conditions to the cheaper to manufacter, but VERY **** RETENTIVE Speed Density system. This is not my area, but I've read on the board that it's just apparently easier to go back to MAF or repair & replace all the Smog systems. You might be a tuner-whiz and love data logging. I guess that's what it's supposed to take if you de-smog a speed density system. Also, you're probably already aware of this, but you can't mix a 305 PROM with a 350 engine.

So how else can we be of help for ya? Nitro-Nicky

 

im not sure what u mean by background information of my current prom.but i am pretty sure its just stock from a 92 firebird trans-am.i assume this b/c when i bought the motor ,ecm and harness everything was stock and had not upgrades.The scanner i used was a snap-on and i wouldent think it was bad connestions b/c i used the same scanner on my tbi motor and that used the same obd1 connector.i am not sure if the guy that dynod my car used the port but i will have to find out.

i do have a boshe o2 sensor but the car seems to be running well the only time. the car throws a code is when i am drivin on the highway for about 20min , i forget the number of the code but its for the egr so i am assuming i need a new one.when i changed motors i never got a new one b/c of there value.

thanks for your help

 

Could they have made those EGR's any harder to access???

 

Code 32 is for the EGR system. And based on what you described above for the light coming on, either the EGR valve isn't opening, or there's a clog in the intake manifold passages that's not allowing the EGR system to function properly; the EGR valve might be stuck closed; or the EGR valve could be faulty. But probably the valve just isn't getting any vacuum to open it, possibly due to a faulty EGR solenoid not allowing any vacuum to the valve, or due to a leak in one of the vacuum lines(good bet it's a leak). And regardless of which it is, the engine will still run strong.

So pull out the vacuum lines associtated with the EGR valve and EGR solenoid and look them over very carefully and completely, all the way around, and look for cracks or holes. And if you find any, wrap them with black electrical tape, then clear the codes and take it for a drive on the highway to see how it does. I doubt the light will come on anymore.

Code 12 is simply the computer's way of telling you its own diagnostic system is working properly(kind of like when Captain Kirk would talk to the ship's computer, and the computer always began by saying, "working," lol). So everytime anyone checks for codes, code 12 will/should always appear. If it doesn't, then there could be a computer problem. But you're getting it, so no worries there.

Regarding your scanner, you apparently have a scanner that works with both, OBD1 and OBD2 systems. For OBD2, it simply interfaces with the car's computer and reads everything automatically... nice and easy. But for OBD1, you probably have to program the scanner and input the car's data manually so it will know what it's scanning. And yeah, they don't always work right, so flashing for codes ends-up being the best way to get an accurate reading of an OBD1 system.

 

I've been ignoring my Iroc for so long that I totally forgot some of the material I have.

Check out John Baechtel's book: CHEVY TPI Fuel Infection Swapper's Guide

It goes through the 85-92 tpi systems, converting back & forth between SD and MAF, All the sensors and details the engine code info. It's really-really thorough!

If you do check your EGR system and find that it might be a bit gunked up (and possibly the leading culprit to the code issue), run a SEARCH on using 'SEAFOAM' through your vaccuum system. Several of us, myself included, have salvaged our EGR valve till we could get to it at a more convinient time. You probably already have even heard of it, but just in case....

Again, I apologize for my 'misplaced' or 'untimely' humor for when you initially placed your post. It wasn't meant to rile you. I promise to be more careful for the next guy-
Nitro