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Hello all,
Im putting my Vette back together and have a question before I proceed. There is a small box under the plenum that houses a few vacumn hoses and a electrical plug that comes from the injector bank. At the front of the box is a port that looks like it at one time housed a line, possibly another vacumm hose. Can anyone tell me what connects to this port and if it needs to be connected or plugged. I have enclosed a picture. Thanks for any help..I dont want to proceed in case I have to address it. Wont reach it easily if back together.
Before I put this back together I have a question. I can find a piece of foam to put here and reinstall but I am considering just replacing the EGR solenoid while I am there. The reason being that lately I have been experiencing stalling and stumbling upon acceleration. This has been happening the past few weeks. Not all the time and it runs very well when its not. No codes except a slight flicker once when it stumbled. I don't like throwing parts here but I gladly will while it is apart since I don't want to take it apart again to replace this
What are anyone's thoughts? I see them on Corvette Centrals site. I will be in Carlisle tomorrow and will look for one.
lol thank you....but meaning that my mechanic plugged my EGR maybe 2 years ago and the hesitation stopped....until about 2 weeks ago. I just changed my EGR valve, my ICM, my coolant temp sensor, and plugs...while everything is easier to reach. I'm just worried that i'll put it together and my solenoid will be at fault. I can swap out my O2..that is easy but the solenoid with everything together..
The egr solenoid is just a simple switch that is commanded to open by the ecm. You can test it (removed) by adding voltage to it. You should hear it click when you do this.
The egr solenoid is just a simple switch that is commanded to open by the ecm. You can test it (removed) by adding voltage to it. You should hear it click when you do this.
Thank you for the tip Dt86. Tested the one I have per your suggestion and it seems fine.
Thank you for the tip Dt86. Tested the one I have per your suggestion and it seems fine. Kevin
Glad to help Kevin. They are pretty stalwart parts, which is good since you can only find them used. When I put my intake back together last year I noticed that the bracket for it was a tight fit in there. I ended up trimming some of it off for an easier install.
The title says it all. I received a ton of help the past 3 weeks doing some work on my 1987 Corvette Automatic. I replaced the ICM, CTS, EGR valve, and spark plugs. Everything to spec and meticulously taken apart and installed. Got it back together today and it fired up and immediately stalled. Not too worried I tried again and same thing. Started but would not run...not even with feathering the pedal. I walked away in disbelief. These were simple repairs and something always goes wrong. I disconnected the MAP sensor and it now idles a bit rough but can be driven. Stumbles a bit but under acceleration runs very well...better that previously. Got it home and reconnected the MAF and it would start but not run. My MAF is close to 5 years old and looked a bit dirty. Could this be my issue? It ran fine before and I was careful in handling the MAF sensor. I will try to clean it tomorrow. And would gladly get a new one if that is my issue.
Hello all, The title says it all. I received a ton of help the past 3 weeks doing some work on my 1987 Corvette Automatic. I replaced the ICM, CTS, EGR valve, and spark plugs. Everything to spec and meticulously taken apart and installed. Got it back together today and it fired up and immediately stalled. Not too worried I tried again and same thing. Started but would not run...not even with feathering the pedal. I walked away in disbelief. These were simple repairs and something always goes wrong. I disconnected the MAP sensor and it now idles a bit rough but can be driven. Stumbles a bit but under acceleration runs very well...better that previously. Got it home and reconnected the MAF and it would start but not run. My MAF is close to 5 years old and looked a bit dirty. Could this be my issue? It ran fine before and I was careful in handling the MAF sensor. I will try to clean it tomorrow. And would gladly get a new one if that is my issue. Thanks for any continued advice, Kevin
Don't feel bad it's not just you that these things happen to! Did it throw any codes? Double and triple check everything. If it ran fine before then you likely missed something.
Don't feel bad it's not just you that these things happen to! Did it throw any codes? Double and triple check everything. If it ran fine before then you likely missed something.
There was a code but I assume it was because I disconnected the MAF. Ill check again not sure I got a code prior. Ill check everything again but I took my time and triple checked everything. Is it coincidental that it ran better after I unplugged the MAF? I really didn't do too much of anything else. I also cleaned the IAC while the throttle body was off. That part is only 2 years old however.
There was a code but I assume it was because I disconnected the MAF. Ill check again not sure I got a code prior. Ill check everything again but I took my time and triple checked everything. Is it coincidental that it ran better after I unplugged the MAF? I really didn't do too much of anything else. I also cleaned the IAC while the throttle body was off. That part is only 2 years old however. Thanks for any advice, Kevin
When you unplug the maf sensor it forces the ecm into open loop. In open loop the car is running in default or "limp home" mode and is no longer running off of any sensors. Check the fine wires in the maf sensor just to make certain none got broken or dirty while apart. If they look dirty do not use anything other than maf cleaner on it. Also take a good look at the maf weatherpack connector to make sure the wires and connectors are all good.
When you unplug the maf sensor it forces the ecm into open loop. In open loop the car is running in default or "limp home" mode and is no longer running off of any sensors. Check the fine wires in the maf sensor just to make certain none got broken or dirty while apart. If they look dirty do not use anything other than maf cleaner on it. Also take a good look at the maf weatherpack connector to make sure the wires and connectors are all good.
Ok...I will check those tomorrow. Could a faulty out of the box CTS cause this condition? A faulty ICM? I cant wrap my head around that being the problem. Starts up and shuts right off. I assume that even a bad sensor the car would still run even poorly.
Thanks again,
Ok...got home from work and triple checked everything again. All sensors plugged in, etc. I checked my MAF and it is still relatively clean and the three thin wires are in tact. Tried it again no improvement. Starts but then dies right away. I checked my codes and got a single code 33...I assume when I unplugged the MAF last night. I might have to go back and check each installed part to see if they are good. My question is...can I eliminate any of them before checking them? I mean with the MAF unplugged it runs somewhat ok. For example can I assume that the new ICM is ok since it starts with the MAF unplugged? Same with the EGR and CTS? Another thought is that even though I cleaned the TB and the IAC seperatly and was very careful..could parts cleaner have ruined it? Same for the TPS? I was very careful not to spray near the sensor.
Disconnected the TPS...no improvement Reconnected it
Disconnected the IAC...no improvement Reconnected it
Disconnected the CTS...no improvement Reconnected it
I'm starting to believe that it is in the TB. I cleaned it when it was off. I'm not real sure how to do it but I sprayed carb cleaner on the butterfly flaps and cleaned with a toothbrush. Cleaned the outside as well as the IAC passage and the IAC ( out of the throttle body ). My question is...if the TB is dirty or clogged, will disconnecting the MAF compensate for that issue to run better? I'm out of ideas and frankly this job was very simple. I cant keep looking at it before it goes to the garage.
08-25-2016, 07:23 PM
Please help to identify this part
I disconnected the MAP sensor and it now idles a bit rough but can be driven. Stumbles a bit but under acceleration runs very well...better that previously. Got it home and reconnected the MAF and it would start but not run. My MAF is close to 5 years old and looked a bit dirty. Could this be my issue? It ran fine before and I was careful in handling the MAF sensor. I will try to clean it tomorrow. And would gladly get a new one if that is my issue.