LarryD

The engine is running fine but once in a while throwing a Code 32 (92RS). I did the break-in process for the cam and then drove easy on it for 500 miles. The EGR Valve is new. Someone suggested that since I put in a slightly more aggressive cam that I need to have the ECM tuned. When it does throw the code, it seems to be when I decelerate on slowing to a stop. This is the only code it has thrown. It is the electronic EGR so no vacuum lines running to it, only wiring. Wondering if anybody that has done the swap might have run into this problem before?

Thanks....

RBob

iTrader: (1)

The ECM tests the EGR during the decel coast period. It does this by opening each pintle individually and measures the change in manifold pressure. I can see changing the engine displacement or the cam causing this error.

Some retuning of the ECM is a good idea, can also tweak the EGR or disable the malfunction code for it.

RBob.

LarryD

It was running fine with the old engine/old EGR valve and no codes even though when I took the EGR valve off the old engine it had a crack into one of the pintle holes. I needed one to get the initial cam break-in done so I used the one that was on the 3.4 engine assembly (same part number) and appeared to work although it was throwing lots of codes due to the quick timing I did for the break-in. It got seriously overheated on the first run so bought a new one for it.

Since it started happening with the engine change, I thought either I had missed something or it is due to the changes from 3.1 to 3.4. I checked all the notes I could find on here about the swap but didn't see where anyone had run into this problem.

Guess I need to find somebody in the Boulder to Denver area to tweak the tune. First quick check of the mileage come out just above 30mpg and the engine was just getting broken in.

Thanks....

LarryD

Well, it doesn't seem to throw a code 32 anymore but is now throwing a code 13 and code 44. Both point to the oxygen sensor. Any swap guys run into a lean problem after the swap? My oxy sensor isn't that old but maybe it went bad with the extra hot exhaust gas temps during the first 20 minute break in run...

LarryD

Ok, so it still throws a code 44 and the mileage is really bad.. Don't smell any raw exhaust though.. Beginning to regret the 3.4 swap.. May have to just take it in to a shop I guess unless anybody has any ideas...

Update: Checked Fuel Pressure and got 40 steady only dropped to 38 under throttle acceleration.. FPR was new about a year ago and the pressures were the same as then.. Checked Vacuum and got a rock solid 15 off the port at the back of the upper plenum.. Vacuum needle didn't even twitch... Kind of expected higher on a new engine build...

Guess I should add that I am in the Denver, CO area so significant altitude change from sea level in Washington state. Don't know if that would explain why the error codes after the 3.4L swap when I didn't get them at sea level on the old 3.1L...

Thanks...

RubberDucky

iTrader: (4)

My 3.4 ran rich, if you've got a spare O2 sensor I'd put it on and see if it helps.

Gfunkill

Mine runs real rich when it's cold. You can smell it. I don't know if the light is on or not B/C the PO unplugged it/took it out. I don't really care if it throws a code. Mine gets 20-22 MPG mixed driving, and before the trans went (stupid 700!) it was a joy to drive with the 3.4 vs the battered 2.8 it had.
I don't know about altitude problems, I'm in FL, where it might get 250 ft above sea level.

LarryD

Ok, time for another update.. I took it into Midas (too cold and wet to crawl under it).. It did have an exhaust leak on the driver's side.. When I hooked it all up on installing the new engine, the inner ring on the donut gasket caught on the edge of the manifold and bent over.. It was leaking right there.. The guy at Midas had to bevel the edge of the new one so it would slide in.. Guess I could have played with it a lot laying on my back and never get it straight.. Anyway, since they had it up in the air, I had them replace the O2 sensor for me.. Knock on wood, so far after about 45 miles I haven't had anymore codes..

When I looked at the bad donut gasket, it is pretty black from running rich... Being at this altitude, I figure the air density is just too low even though it is cold.. So, she needs to breath more at least.. I bought the air induction intake for the V8 off EBay and that should be here next week.. It has a much larger intake cross section at the air filter than my stock one.. I will get a pair of K&N filters for it and then see how the mileage goes.. After that, I am headed to see a guy in the area that is supposed to be top of the line on ECM programming.. I figure at this point it is not getting enough air and the ECM just can't compensate enough for the altitude.. I drove the car from sea level in Washington to Denver.. The first tank of gas on the less than totally broken in engine and at sea level got 30mpg.. Here it is getting maybe 15mpg... More work to be done...

RubberDucky

iTrader: (4)

I got 15 with my 3.4, maybe 20 on the interstate.

LarryD

Wow, now I am really beginning to question swapping from 3.1 to 3.4 since this is my daily driver.. I haven't seen any real change in performance other than lost mpg at this point. My factory 3.1 got 36mpg on the highway and 28mpg city. My second 3.1 got 28mpg highway and 26mpg city. Even at the end when the second 3.1 was getting on the downhill side it still got 23mpg highway and 20mpg city.. Maybe after getting it more air and re-tuning....

willexoIX

I hope thats a typo and you meant 30mpg. If not I call BS.

LarryD

Why do some people have attitudes on here.??. You can call BS all you want to but the fact is that it did get 36mpg on the original factory engine at 70 on the freeway in cruise control... Granted it may have been one of those very rare occasions where everything came together perfectly in the engine build. So, I will not debate the point, but, if you have some helpful information on improving the 3.4L performance post swap that will be helpful to everyone that is great and I think everyone would like to hear it or see it added to this string...

All that said, quoted spec on mileage for the 95 Camaro 3.4L which is where the block came from is 26 highway and I think that is a very reasonable target at least. Hopefully with proper tuning it will go higher. Hell, my new (less than 10,000 miles) 2010 2SS gets 27 highway regularly with the 6.2L engine...

Thanks for any help you can offer...

willexoIX

No way no how. Unless you had 2 clogged injectors. Thats hybrid mileage and for something built in the early 90s no way in hell. Proof or it didnt happen.

The 2.8 wouldnt get near that and you are trying to get us to believe a 3.1 did. You must be mistaken. Was the ecm tuned? If the ecm was stock I dont care how much you swear you got 36mpg.

If you said 30 I would have believed you.

A 2010 v6 Camaro gets 34mpg tops, so I stand by my original statement. Facts are supported by proof.

LarryD

Latest Update: After about another 130 miles it still looks like its getting about 15mpg even after fixing the exhaust leak and putting in the new O2 sensor.. Good news is no more error codes. Next update will probably be in a week or two after I get the dual snorkel air intake and K&N filters installed to see what if any effect that has..

pontiacguy1

Is your MAP sensor working properly? The 3.1 used a MAP sensor and not a MAF. IF that thing is not reading correctly, it could be dumping too much fuel in. That could be why the altitude is affecting you so much, the MAP thinks that you're flowing more air than you really are.

Also, I measured 31 MPG in my 1992 3.1 V6 Firebird on several occasions, on the interstate with the cruise control set on 72 MPH. I don't know about getting 36 MPG, but I've seen low 30's myself, so these cars are capable of great mileage. Imagine the mileage you could get with a more modern drivetrain in one of these, such as the 3.6L out of the new Camaro.

willexoIX

Its like I said, 30-31 I could have believed, but our v6s getting better mileage than a new v6 Camaro is far from believable.

RBob

iTrader: (1)

Yep, that is where the intake runner length is perfect. Reduces the pumping losses tremendously. If using the go-pedal to hold that speed it is very easy to let it creep up.

With better ECM firmware it is now in the 32-33 MPG range on long highway trips (600+ miles).

The one thing that will kill mileage with these cars is cool wet weather. It will easily halve highway mileage. Don't know if it is due to the O2 sensor being cooled off, or if there is false knock retarding the timing.

Both issues can be caused from water spray onto the exhaust pipes. A cold O2 reports lean (ECM adds fuel), while the pipes could be contracting and making noise (false knock).

RBob.

LarryD

Thanks for the input Pontiacguy and RBob. Hadn't thought about the MAP but now that you mention it, it is the original MAP and has never been changed. I might just go buy a new one due to its age although it hasn't thrown any codes that I would associate with the MAP. Also, with the 3.4L conversion, the knock sensor had to go on that short 45deg fitting to angle it away from the starter solenoid so that could be causing an issue but no other way to mount it. That only pushed it out about an inch on the extension and I used the steel fitting and not the brass so pretty confident that it will be ok. Put in a new one with the engine swap too since the one I had was also original in the car. It has been super cold here with the usual deicer water splash on the under carriage.

LarryD

Time for an update and summary.....

Replaced the EGR valve, put in a new O2 Sensor and exhaust leak fix might have increased the mileage about a half mile per gallon. It was at 15mpg after those two things.

The new MAP Sensor might have increased it another mile per gallon. It went to 16mpg.

So, now for the better news. The new dual snorkel from the 5.7L with Wix filters (nobody had K&N in stock) took it to 20.6mpg. A gain of 4.6mpg by opening up the cold air intake. Power is noticeably up but not where it should be. For information, I calculated the cross sectional area of the original 3.1L cold air intake at 1.77 square inches and the cross sectional area of the 5.7L cold air intake at 7.07 square inches.

I still have an unknown vibration that might be affecting the knock sensor. There is always a bit of vibration but it is most notable at about 2200 and 4000 rpm. Although I fixed a bit of the vibration in the exhaust, my center hanger is still in need of fixing. Might try to do that tomorrow.. Not sure that will do anything but it can't hurt since it needs changing.

No codes since changing the EGR valve and the new O2 sensor. I guess I am now at the point that I will need to get the ECM tuned as the next step..