Hello everyone, I do not post much on here but I visit these bords almost daily hunting down good info on diffrent things. I very much enjoy reading the post on this sight.

First of all this is a 1991 V-6 3.1 Camaro acording to the Vin. This is my friends Camaro. I actuly have a LO3 305. I dont know alot about these little 6 cyl's so I have a few questions i was hopeing some one with superior knolodge than mine could help me with. Now, some back history on the car. It has been sitting for 7 months not driving. Do not know if vehicle was frequently started or not. battery is still good. At some point in the car's life it was in a front end collision. The passanger side hedlight area was hit dead on. crunched the from frame work the rad attaches too and everything. it has been straitend back out but you can still see visible evidince from crupled metal in some spots. car is fixed and repainted now. Thats all the history i know on this.

So heres the isue. Car wotn start. Try to start it up, will run like 5 seconds missing bad back fire throu the intake butterfly and die. after that wont start agin. at all. Now ther are a few things going on here i'm not sure about. First off. Did the V6 camaro's ever come with a filter and intake tubing setup other than the "Y" box that sits up by the hood latch??? I have only seen that setup on camaro V-6 ever but i must admit i'v only seen 4 in person and pics on line. This has what i have been told by another club member looks like the Firebird air box. its round, has the air temp sensor in the bottom, sucks air out of the passanger side finder and has a round open tup for the air to go into tubing and then on to the motor. The tubing to run from that round air cleaner box to go to the motor is missing. it dose have the one you would hook up to a "Y" airbox setup tho.... my friend bought the car like this. also the wireing harness is correct for that airbox on the passanger side battary tray. there is no way that wire would reach all the way on top of the rad to plug into the "Y" air box. now that mouting spot for the "Y" air box is compleatly open. on my TBI i had a plastic plate there. on his its gone. no plate. no "Y" air box or anyting. i'm assuming it was damaged in the crash and was not replace. no way to konw what it was before that. The main reason i was wondering if this airsetup is factory or not is we are getting the impression this motor was pulled from a junk yard and dropped into this camaro. maby the orginal was dmamaged who knows. but we know hood and finders came off of a 84 cmaro. can see the yello paint markers. that dose not explain the firebird airbox setup but if the camaro's never came with this setup then it had to have been pulled from a firebird along with the wireing harness and dropped in.

Question #2, Is there a way to tell by looking at the V6 if its a 2.8 or a 3.1? if the motor has been swapped what would happen if some one put a 2.8 in and tried to use the 3.1 comptuer? could this be why vehicle will not run?

question #3, on the V8 motors in i want to say the late 80's they changed the desing, moved the A/C compressor adn ALT. Older motors had A/C on the driver side Alt on pass. on my 91 A/C is on passanger side, Alt is on Driver side. Was this done on the V6 as well or was it allways the same? His setup is A/C on driver side, Alt on Passanger side.

Question #4 Was the V6 allways MAP? or did they run MAF? because i'm thinking if they did make a MAF V6 in the early 80's and thats what this motor is like we suspect then that would be our problem. we do not have a MAF sensor on this setup. if it was MAP it would nto be needed to run. sure you would not want to run with out the airbox hooked up for obvious reasons. but it would run just fine. if its MAF then i'm assuming ti would not run at all? dont know maf system so not sure about that.

I did plug in a code key and we came up with 4 codes.

Code22. TPS voltage was under 0.2 volts for 2 seconds when the engine was running.

Code33. MAP sensor signal voltage was too high (low vacuum) for at least 5 seconds when throttle opening was under 2%.

Code35. Idle speed was over 150 RPM outside the desired engine speed commanded by the ECM.

Code44. Oxygen sensor voltage was under 0.2 volts for 60 seconds of closed loop operation.

Later today or tomarrow we will be trying to test the TPS sensor to check voltage on it. dont konw when the code 44 came about, car has nto been running for soem time now and we have not been able to get it to run for more than 5 or 6 senconds twice only. it wont even start now. Any good suggestions on the rest of this would awsome.

Sorry for the long post. complicated problem hard to describe. Thanks everyone.

-Randy-

 

First, It should have a 3.1, not a 3.8. Unless someone did ALOT of work and put a 3.8 in it.

Q1. Yes, the 91-92 v6 camaros got the "firebird" intake. That goes over to behind the pass headlight.

Q2. The 2.8's got a different upper intake, and they had a cold start injector on the back of the lower intake. All easly swappable up to a 3.1 style. Would need to run the vin off the block which is on the drivers side, side, back by the bellhousing.

Q3. That alt is in the correct location.

Q4. 85-90 2.8's were MAF, 91-92 3.1's were MAP.

A backfire thru the intake sounds like some valves are stuck open, or the famous bad timing chain issue.

 

Thank you. This answers ALOT of questions for us. This will be very helpfull.

-Randy-

 

I've never seen a Camaro V6 with the Firebird style filter.

Every V6 I've seen, regardless of year, has the TPI style filter housing. The V6 ones have the IAT fitting in them, the V8 ones don't.

 

My 92 had the filter behind the head light and my ex-girlfriends 91 was also there.

 

Then you have only seen modified 3.1's, or 2.8's.

It is very popular for 3.1's to install the 2.8 intake due to the restrictive stock intake of the firebird style.