Ok here's what I have done so far:

First this is a 1996 Camaro 3.8 with 180,900 miles on it. Several months ago I noticed that oil was leaking into the coolant (no coolant ever leaked into the oil, plus I changed it just in case). I drove it for a few months until I had time to change the intake gasket. To confirm it was an intake gasket and not a head gasket I did a compression check, all were well within the range they were supposed to be (actually almost like new). I changed the intake gasket and after seeing it, it was definatly the problem. Upon removing the intake I broke the Engine Coolant Temp Sensor so I replaced it with an auto zone one (never will go back there) I started the car up and I had all sorts of problems, first the fan wouldn't turn on, so I went to get a GM Engine Coolant Temp Sensor and that fixed that. Second the engine was reving at 2000 RPM's at Idle, I found that the cruise control cable readjusted while I had it pushed out of the way when removing the intake. I readjused that and that fixed that.

Ok now for the problem that I haven't fixed yet. The first start of the day I have to crank it and crank it before it starts, then when I drive it it runs rough boggs down and pops until it warms up. Once it warms up it runs better but not perfect. At higher RPMs and speeds it does ok, wide open throttle it does ok. However at low RPM's combined with low speeds it boggs down and loses power, if I mash on the throttle its ok again. I sprayed ether start all over the intake to check for intake leaks.... since the engine speed didn't increase I ruled out an intake gasket leak.

Just before I changed the intake I did get a 1441 (EVAP purge in a no purge condition) code however drivability was ok. so while I changed out the intake I changed out the purge solenoid and vacuum switch. Once I started it after the intake change the problems were still there, so I did a vacuum check of all the vacuum lines and did a vacuum check of the vapor canistor. They all passed except minor leaks in the vacuum lines. I replace all the rubber in the vacuum lines and re did the vacuum check, its tight now. I also blew out all the vacuum lines and no charcol what so ever. I am still getting the 1441 code though and it still drives the way I just explained. I don't know if the 1441 code is related because it happened before the intake change with no problems but I am still getting it after the intake gasket change but now all of a sudden drivability problems... I don't think I need a new canister as it seems ok, the rest of the EVAP system is new, but I still get the code. I also triple checked the vacuum line routing.... its is correct.

Can the Fuel vapor control valve (between the vapor canistor and fuel tank) be causing the problem?

If this is not 1441 related what else could cause it?
At the same time I put in new plugs and wires, I even recheck them and replace one I let get burned on the exaust. They all pass Ohms check too. (between 10 and 500 ohms [25 ohm per foot wires]) GM manual says its good as long as its under 30,000 ohms. One last think I just noticed, the fuel pump is very noisey just after I shut off the car and lasts for 5 seconds or so. My wife says she heard it before too but I never noticed it till now... maybe I listen more when I have problems. I tried to find a fuel pressure gauge but auto zone doesn't carry them..... (another reason i will never go back).

Anyone have any ideas... I am now at a loss... been at it for 3 weeks!

 

Ok this morning the car started up right away... so looks like fixing the deteroiated vacuum hoses by the canister helped it a little. Still bogs down and loses power at lower RPM's. I did finally get two more pending codes (no MIL light yet) The codes were P0171 and P0174 , bank 1 and bank 2 running lean....and still has the P01441 code pending........ so what do you guys think? Is my fuel pump going.... with the more noise I'm hearing from it? Anyone know where i can buy a fuel pressure gauge?

 

Ok as if this cant get any weirder, I went to Kragen and got a fuel pressure gauge brand new. I put it on the fuel rail and took the pressure key on engine off. It was only 15 psi. I started the engine and and got only 30 to 35 psi (48-55 is nominal). To elimanate the fuel pressure regulator being stuck open, I took off the return fuel line from the rail and put a plug on it (it was completely dry by the way. I started the car.... same pressure. i took the plug off and started the car.... no fuel what so ever at any RPM came out the return line. So it looks to me that the fuel pump is just not pumping enough pressure to get the fuel regulator to open.

So bad fuel pump? Still pumping but not enough? What are your thoughts?

Oh and does anyone have the link to the 4th gen camaro where they cut a hole in the trunk to remove the fuel pump... I might consider that.

 

the fuel pump could play a role but I had the same problem with bogging down after replacing the intake manifold. turned out a tuneup and a new EGR valve fixed that problem (at least till a coil pack died out). have to agree that the fuel pump is going out though sounds like the lean codes are a result of not enough fuel getting in there. especially with both banks at once.

 

Thanks, how did you determine that it was your EGR valve? Did that throw any EGR code?

Yeah, mines had pretty much a good tune up... New wires, fairly new plugs (a few thousand miles on them) new PCV valve. The coil packs are only 6 months old and so is the ignition control module. I am going to replace the fuel filter although its on got a couple of years on it.... first one lasted much longer and I canged it just because.... it was still ok.... but its a cheap part rather than the fuel pump just yet.

 

It was several years ago so i don't even remember how i determined it. all I remember is that after the tuneup it still ran like crap and i was somehow able to narrow it down to the EGR valve

 

Ok the EGR definatly had nothing to do with it, at least in my situation. (I swapped in a brand new one and no change. It has to be the fuel pump with only 30 psi. Now I looked at the websites for the auto stores and they all have pretty much the same fuel pump for this car, however it says it pumps 50 gph at 30 or 35 psi (can't remember the exact psi). The book says mycar needs 48 to 55 psi, Is it just the way it is measured? Will the replacement pump produce 48-55 psi in the fel rail or is it a case where the parts store has one pump for too many applications?

Second I have seen a 255lph pump that is cheaper, now I know my car would never need this much fuel but would it hurt it? Any added benifit such as the pump not having to work as hard so it might last longer?

 

ok yeah after getting that reading I think you may be right. I can't find my Haynes manual at the moment so I can't confirm but my gut says you're right on that. and if that is the case then that may be a case of a parts store having one pump for too many things. And as far as the 255lph I don't see where that would be a problem unless you have weak fuel lines that couldn't handle the extra pressure.

 

Thanks, I finally changed the fuel pump and it fixed everything, Weird how it only showed up after the intake change. I also got back some performance I forgot the car had. It runs much stronger now with the correct fuel pressure!

 

Lol yeah it does make a difference. and it probably just happened to start having issues at that point I doubt it was actually connected to the intake gasket change