Drove it with the map unplugged and acceleratted fine up to is second gear shift (auto). Plugged it back in ran like it did.
That sounds encouraging! A low vacuum will cause a rich mixture. You do need to scan and see if you go into closed loop, I am still concerned that your O2 sensor is failing and keeping you in open loop. Keep digging your getting close!
[This message has been edited by Robertzep2 (edited 05-24-2013).]
Since low vac can cause a rich mixture, I dont know if my cam is bigger than stock. It has a considerable amount more duration then a comp cam I have but less lift ( using stock springs in heads) I bought a block and several other items of a person and in those items was two brand new cam's and a used cam. I decided to go with the cam with less lift and more duration due fiero intake and the less lift is easier on parts. Also its a 2.8 bored .040 over and has a 3.1 crank and pistons.
I know a bigger cam will lower vaccuum.
I will be buying a new 02 sensor and sticking it in here shortly. I will use your method and test if my car is coming out of open loopnas well. ( before and after 02 purchase)
Also just re read my last post and it didn't make much sense. When I unplugged the map sensor and drove it it accelerated fine with very little throttle and in second it hardly have enough power to drive 20 or 30 mph.
I have a code 34 but there is no error code just when I jumper the A and B terminals.
Code 34 is the map sensor so should I just replace it?
If your cam is giving you less vacuum than stock you might need to recalibrate the map limits but I wouldn't change the map just yet. You would need a pretty wonky cam for the vacuum to drop low enough for a code 34 to set. The ECM map window is pretty large.
Code 34 means the map voltage is high (low vacuum/high pressure.) When the engine is off, the map reads the atmospheric pressure which is 14.7 psi (at sea level.) That should be around 4.2V on the map. When you start the car, the vacuum of the engine pulls the map voltage down (less pressure) and the voltage will drop to around 1-2V or so at idle.
I think your problem is a hose leak to the map and it's not getting the vacuum (or full vacuum) from the engine and it's throwing the code 34. Idle the engine, remove the vac line to the map and put your finger on it. Do you feel vacuum? If not, fix that first. If necessary, run a single hose from the TB or upper manifold port to the map directly and check it. If you do have a good vacuum them I might consider replacing the map but they don't go bad all that often. Replacing it's the first thing to check. If you have a scanner, look at the map voltage with the engine off. it should be over 4V. Then suck on the hose and it should drop towards 1V (you probably won't get to 1V completely.) If that doesn't work, then the map is probably bad or your cam is really giving you low vacuum.
[This message has been edited by TK (edited 05-29-2013).]
I just fixed my son's 3800 today with the same problem. It was the IAC. The unit itself was fine but it was filthy and so was the niche where it mounts. I used throttle body spray and a baby bottle brush to clean the IAC and inside the hole. I had to spray the brush clean and then stick it back in the hole many times to get it mostly clean.
The IAC had two different screws holding it in so I'm betting someone else messed with it at some point. He's just had the car one month and it is a 1993 Park Avenue. I'd say someone tried to swap the part and didn't bother cleaning out the mounting hole.
Got code 44 away and 34 hasn't came back but I didn't do anything to solve code 34. I took my 02 sensor out to clean it and it was dirty. Sprayed cleaner on it heated it up and sprayed more cleaner on then sprayed all the gunk out with an air hose.
Now wondering where the best place to buy a scan tool or download something to a laptop to read codes like scan tool?
Re timed it and drove like a champ: no codes or stutters from take off but my Fcc is engaging then disengaging around 35 to 45 making the car shake a bit but I know why.
My car is idling around 600 to 700 and will not start unless I open the throttle up a bit but I can now let go of the throttle and let it idle. Sometimes when I come to a stop sign it will die and will die everytime I come to a stop with the fan on.
Well the car is running lean from backyard mechanics type test.
Sprayed gas into the intake from spray bottle (after the filter) and the car idle went up a bit and when held at a steady rpm (the rpm generally doesn't hold for long until it falls down then raised then falls then raises) the engine ran smoother with no misses and held an rpm that was about 300 - 500 rpm high then when not spraying gas.
Any suggestions? Or do I need to elaborate a little more?
Also after ready the comments I can see why you said FCC, because I said it. I did mean TCC.
I think someone else might have mentioned this earlier, but did you change the fuel filter? I had a rough and high idle that surged, I changed the fuel filter, found a loose boot on a plug wire, and cleaned a dirty throttle body and it runs great now.
------------------ 1997 Grand Prix GTP-(totaled) 1993 Firebird Formula-(Sold) 2006 Grand Prix GT-(Sold) 1988 Fiero Formula 5spd T-tops - Current Ride 2011 Chevy HHR LT - Kid hauler Its better to burn out then fade away (but you go through more tires)
Also, does your temp sensor read correctly on a scanner? I have a Formula that had a new temp sensor but the plug terminals were corroded inside, it thought it was at 38 degrees all the time. Would run rich & keep it in closed loop.
[This message has been edited by AL68 (edited 07-23-2013).]
Man now I see exactly why you pm'd me... pretty much exactly what mine does.... this is what I did I took a small common screw driver and placed it between the stop for the throttle body...hel it in place and had my bro start it. It idled.... little low but it held an idle... so I pulled the butterfly out and shaved a little from the bottom and top allowing just a bit more air into it... she starts and idles fine.... only issue It has is when driving it coming to a stop it stalls "when I push the clutch in" .. but not all the time... honestly I think it needs a tune.. or according to my bro some boost to get the air flow up.. do you have a stock pcm or upgrade that aswell?
Deff better when its warm... as for iac I completly removed the internals from mine so it gets the most air as possible thrue the tb... only issue I can think of is lack of vaccume. Idk?? As I said I ended up shaving my tb butterfly to get a bit more air and now it hold and idle.. if you do shave ur tb do it in very smallllll incriments bc if you shave too much it'll idle extremly high and run lean at idle..
maybe try to find a set of 3.1 heads? had a buddy with a 350 that had 305 heads on it and it acted almost identically to what your describing. Other than that if youve ran some kind of treatment through your fuel system your gonna wanna replace the filter again unless you pull it off and the fuel that comes out is clear. I don't think bigger injectors would do much for you. WIth it having a cam you may wanna look into a different set of rockers maybe? I'm just throwing some ideas out based on my experience with 3800's and 350's
Just a quick question.. why do you think its running lean??? Try what I did have someone start the car while you ever so slightly hold the throttle open.. by literally a few mm. If it runs bettter and idles then you're not getting enough air.
I used a spray bottle to spray gas into the intake and it ran a little better. The car dies cold no matter what. Even if I hold the throttle at a constant 1500 rpm's cold it will die after a few seconds.
Also just through code 35 today. Looks like I'm doing another IAC reset. (only code)
Ok try this . On the tps there is a lever that moves with the throttle. Take a pair of needle nose pliers and bend it a bit. As though you are opening the throttle when you really aren't.. basically tricking the pcm to believing throttle is open 10-15% and to add more fuel