Should I remove that hose and block both ends of it? One on air cleaner and one on the metal pipe coming behind engine and firewall?
If the left valve cover has hoses going to the metal tube on the firewall that leads to the air cleaner, then it sounds like it's just hooked up the pre-recall way which, I'm thinking, should not actually be the cause of your problem.
If you haven't already, I'd try and pull a code from the computer. Just because the engine light is off doesn't mean one isn't stored there. You could have more than one actually. It might give you a clue as to what's happening.
Have you had a compression check done on your engine recently? I'm wondering about the condition of the rings.
I got the issue to go away when I unplugged the TPS - but there's no code showing up for that? Have a new TPS coming in the morning to eliminate that problem.
Found directions from Ogres Cave. I'll try this again in morning before replacing anything else lol.
Port Injection, 1985-88 V6 Fiero Plug any vacuum port, as required. Jumper ALDL terminals A & B. Turn on key, engine off, and wait 20 seconds. This will close IAC pintle. Unplug IAC while key is still on. Turn key off and remove the ALDL jumper. Start car and set Idle Stop screw for 800 +/-50 RPM. (750 - 850 RPM is fine.) Shut off the car and plug the IAC in. Replug any vacuum ports.
When it tries to die I hear this big surge of air, like the IAC is all the way open trying to keep it alive. I only heard it before when the engine tries to die, but now I hear it all the time...
Well it has to be something vacuum related. It wants to run fine until under load and when the IAC tries to compensate it can't adjust enough to raise the idle sufficiently.
It closes up (iac) and when the engine tries pulling air through the intake it starts to stumble then dies.
I type freely on here (a lot). My replies are more like checking off things and taking notes than asking for help or favors. I do appreciate the insight and recommendations because, well, more brains are better than none. But I do plenty of research off the thread and part replacements. I'd say in the short amount of time I've started this thread I've crossed quite a few things off the list.
The MAP code is a big deal, the ECM depends heavily on the MAP in it's fuel calculations. Replacing the sensor didn't help, so I'm guessing there's a vacuum issue which is causing the MAP to give bad information. From what I remember when messing with my car, unplugging the TPS will make it run more rich. So since that's helping your car run better, it's probably lean.
I think you're on the right track looking carefully at all your vacuum hoses, see if you can find any leaks anywhere. Especially look close at the vacuum line at the passenger side of the manifold, which goes to a T. One end of that branches to the fuel pressure regulator, the other to the MAP sensor. You need good vacuum in that line. If you find fuel in that line, it indicates a bad regulator. If you want to gamble try sucking on it and try not to swallow any. Old gas is nasty. Sometimes when the regulator fails they start leaking into the vacuum hose. Not sure if that can cause problems with the MAP readings.
If you can, try checking the fuel pressure. It should be about 43psi key on engine off. It should drop to around 38 with engine idling. The fuel pressure regulator is referenced against manifold air pressure, as described above, so you should see the fuel pressure adjust in relation to that. Also, if you were to backprobe the signal voltage on the MAP sensor, and simultaneously watch the fuel pressure, you should see the 2 moving together. They both are reacting to the same vacuum. If you get low fuel pressure, try pinching off the return line. I'm not sure where is the best place to do that. If pinching it off gets you to good pressure, then the regulator might be the problem, not necessarily the pump. When you turn off the key, it should hold fuel pressure. It shouldn't lose more than a few psi in 15-20 minutes. If it leaks down quickly there's a leak somewhere, likely an injector. Since the car has been sitting, bad fuel and fuel system problems in general become more likely.
You might want to take out the IAC valve and try to clean up the passages in the throttle body as much as possible. Sometimes they get full of grime and that makes it difficult for the IAC to do it's job. Might as well clean the throttle plate while you're in there. This is just stuff that's a good idea to clean, but it doesn't explain the MAP issue and so it's probably not a significant problem. The long starts in your video make me wonder if you have a bad fuel pump relay, or maybe a non functioning cold start injector, but this might all go away when the MAP code is figured out.
You might have an electrical grounding issue - that could be a factor in why the idle drops a bit when you push the brake. If the ECM has a bad ground, it might be wigging out causing it to suddenly stall. But again, I think the MAP problem needs to be resolved before assuming too much about other possible issues. It'll never run well without a good MAP signal.
The ECM is programmed to target an idle speed of 900rpm when engine is warm. It's normal for it to go higher when cold though. If it saves against a stall it will surge up to 1500rpm or so, as I think happened in your video.
[This message has been edited by armos (edited 03-10-2014).]
The MAP code is a big deal, the ECM depends heavily on the MAP in it's fuel calculations. Replacing the sensor didn't help, so I'm guessing there's a vacuum issue which is causing the MAP to give bad information. From what I remember when messing with my car, unplugging the TPS will make it run more rich. So since that's helping your car run better, it's probably lean.
I think you're on the right track looking carefully at all your vacuum hoses, see if you can find any leaks anywhere. Especially look close at the vacuum line at the passenger side of the manifold, which goes to a T. One end of that branches to the fuel pressure regulator, the other to the MAP sensor. You need good vacuum in that line. If you find fuel in that line, it indicates a bad regulator. If you want to gamble try sucking on it and try not to swallow any. Old gas is nasty. Sometimes when the regulator fails they start leaking into the vacuum hose. Not sure if that can cause problems with the MAP readings.
If you can, try checking the fuel pressure. It should be about 43psi key on engine off. It should drop to around 38 with engine idling. The fuel pressure regulator is referenced against manifold air pressure, as described above, so you should see the fuel pressure adjust in relation to that. Also, if you were to backprobe the signal voltage on the MAP sensor, and simultaneously watch the fuel pressure, you should see the 2 moving together. They both are reacting to the same vacuum. If you get low fuel pressure, try pinching off the return line. I'm not sure where is the best place to do that. If pinching it off gets you to good pressure, then the regulator might be the problem, not necessarily the pump. When you turn off the key, it should hold fuel pressure. It shouldn't lose more than a few psi in 15-20 minutes. If it leaks down quickly there's a leak somewhere, likely an injector. Since the car has been sitting, bad fuel and fuel system problems in general become more likely.
You might want to take out the IAC valve and try to clean up the passages in the throttle body as much as possible. Sometimes they get full of grime and that makes it difficult for the IAC to do it's job. Might as well clean the throttle plate while you're in there. This is just stuff that's a good idea to clean, but it doesn't explain the MAP issue and so it's probably not a significant problem. The long starts in your video make me wonder if you have a bad fuel pump relay, or maybe a non functioning cold start injector, but this might all go away when the MAP code is figured out.
You might have an electrical grounding issue - that could be a factor in why the idle drops a bit when you push the brake. If the ECM has a bad ground, it might be wigging out causing it to suddenly stall. But again, I think the MAP problem needs to be resolved before assuming too much about other possible issues. It'll never run well without a good MAP signal.
The ECM is programmed to target an idle speed of 900rpm when engine is warm. It's normal for it to go higher when cold though. If it saves against a stall it will surge up to 1500rpm or so, as I think happened in your video.
Extremely informative and detailed explanations. I will start with the vacuum lines again when I get back to the office. I'll pull the intake plenum and start replacing lines until I'm confident a leak is crossed off. While plenum is off I'll replace other parts like regulator and cold start injector and others just to cross those off the list too.
From what I've read the CSI is expensive, so you might not want to replace that if you don't have to. If it actually isn't opening, there could also be other reasons besides the injector itself. Note also that this wouldn't be a factor in the idling behavior, only cold starting. Once the key is released the CSI shuts off.
Something I forgot about- When the key is turned on, the MAP and TPS connectors should both have 5.0V coming in on one of the pins (I don't know which pin). This is a regulated voltage provided by the ECM. This is the input voltage that feeds through those sensors. That input needs to be 5.0V or the output signals will be skewed. I don't think that fails very much but it would be easy to check if you have a multimeter.
If you expose the front of the throttle body, and put your finger over the IAC inlet, it should immediately stall. If it even tries to stay running when you do that, either the throttle is adjusted too far open or there's a definite vacuum leak. Smaller vacuum leaks you might not be able to detect this way though.
Now I'm getting these two codes. Now that the vacuum line that was broken 'now works'. It is tripping the egr vacuum thingy which in turn creates low pressure and shows the code 33?
EGR Vacuum Control Code 32 is by far the most commonly encountered trouble code. The most common cause for this trouble code is a leak in the EGR vacuum lines. This code is often disregarded since a malfunctioning EGR system seldomly has any effect on the car's driveability, and only on the engine's emissions. It's also tremendously difficult to diagnose the problem. If your car passes emission tests and is otherwise running ok, it's often not worth the trouble trying to find the problem. Code 33
Manifold Absolute Pressure (MAP) Sensor The ECM will set code 33 when a problem with the MAP sensor is detected (unusual low vacuum/high pressure). Check the vacuum hoses from the MAP sensor. Check all connections and replace the MAP sensor if necessary.
Brought the car home today. Doing 70 down freeway and temp fluctuated around 220-230. All water no coolant. Had as much power as a Chevy Aveo but sounds better and people stared at me... Lol
Actually had a solid check engine light which is good. Normally it doesn't show up unless it dies. So I guess this drive might have helped. I have tomorrow off and sliding it into garage to be diagnosed and solved. But its going to be stripped anyways. Oh well
Now the only code that shows up is code 32 and it only starts to die after I rev it up and hold a 4-5k rpm.
Seems like it might be starving for fuel? 1/10 times when I turn the key I hear the fuel pump kick on. hmm
Whenever you cycle the key on, the fuel pump should prime for 2 seconds. If that's not always happening, something is wrong. I'd really suggest getting a measurement on the fuel pressure (described in more detail earlier). Keep watching it while it warms up and see what it's doing when the bad behavior is happening. The fuel system is always suspect on a car that's been parked.
Good that you found that taped vacuum hose. Unfortunately that might be a bad sign for the quality of "fixes" you might run into elsewhere.
Whenever you cycle the key on, the fuel pump should prime for 2 seconds. If that's not always happening, something is wrong. I'd really suggest getting a measurement on the fuel pressure (described in more detail earlier). Keep watching it while it warms up and see what it's doing when the bad behavior is happening. The fuel system is always suspect on a car that's been parked.
Good that you found that taped vacuum hose. Unfortunately that might be a bad sign for the quality of "fixes" you might run into elsewhere.
It doesn't happen at all actually. But the engine still runs?? Odd that happens, but it might be why it's feeling starved. The engine is manually sucking fuel into the system and that's why it's hard starting when cold?
Update: Took car home, cleaned up my garage. Baby is parked inside and I'm going to start fixing costmetic things and doing upgrades to inside and out but not tackle an engine swap yet.
I want to solve all problems relating to the engine/transmission before ripping it out and possibly doing a swap with a 3.4, 3.8, n* or whatever I plan on doing...
I'll update back soon and take pictures of my progress.
I did pick up a pair of 'spy camera - glasses' that will record in 2 minute intervals. So possibly get a first person view of me working. I also picked up a nice dash cam off ebay for $20 that I'll mount in my garage to take photos/video. Maybe do something Time lapse related.
Originally posted by kraelo: It doesn't happen at all actually. But the engine still runs??
You might have a bad fuel pump relay. There's a backup circuit which powers the fuel pump through the oil pressure sender. It will close the circuit when oil pressure gets above some level. That might be the only thing that's getting power to the pump. I've never messed with the fuel pump relay so I don't know where it's located, but there should be some info for it on the forum somewhere. From what I remember I think there's a compatible relay nearby that can be swapped with it as an experiment.
You might have a bad fuel pump relay. There's a backup circuit which powers the fuel pump through the oil pressure sender. It will close the circuit when oil pressure gets above some level. That might be the only thing that's getting power to the pump. I've never messed with the fuel pump relay so I don't know where it's located, but there should be some info for it on the forum somewhere. From what I remember I think there's a compatible relay nearby that can be swapped with it as an experiment.
