1986 L-98 tuning questions
#1
Heel & Toe
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1986 L-98 tuning questions
Hey Guys, (Sorry for the long post)
I have a 1980 Camaro with an '86 Corvette L-98 and 700r4.
Recently I had the intake apart, and decided to remove the EGR valve, and all associated plumbing. My issue now is that when it warms up (as soon as the fans kick on) it idles like complete crap. It'll drop to around 400rpm, and then back up to 1000, and back down. Back and forth, and it generally stalls out. I'm assuming it is going into closed loop since it warms up, and is looking for the EGR. Is this a safe assumption?
I know I need to get the computer re-tuned for the removal of the EGR. I just want anyone's opinion on if this would be the cause of it, or maybe something more. I have a Painless wiring kit, and it came with a check engine light module that is mounted near the steering column. When it starts to idle like this, the light DOES NOT come on. That's making me nervous.
Note: I didn't do this for 'miracle' horsepower. I did it because I really don't need it, it cleans things up, and I can run a bunch of wiring under the plenum now.
Also, another issue. I don't believe it to be associated with the EGR, because it ALWAYS did this. If its idling, and I hit the gas, it hesitates, then revs up. I'm thinking vacuum leak, but I haven't come across any. Initial timing is set to 6* BTDC. Any thoughts on that?
Thank you for any information you can provide. If you need me to elaborate more, please let me know. I' not very good at explaining things by writing them out
I have a 1980 Camaro with an '86 Corvette L-98 and 700r4.
Recently I had the intake apart, and decided to remove the EGR valve, and all associated plumbing. My issue now is that when it warms up (as soon as the fans kick on) it idles like complete crap. It'll drop to around 400rpm, and then back up to 1000, and back down. Back and forth, and it generally stalls out. I'm assuming it is going into closed loop since it warms up, and is looking for the EGR. Is this a safe assumption?
I know I need to get the computer re-tuned for the removal of the EGR. I just want anyone's opinion on if this would be the cause of it, or maybe something more. I have a Painless wiring kit, and it came with a check engine light module that is mounted near the steering column. When it starts to idle like this, the light DOES NOT come on. That's making me nervous.
Note: I didn't do this for 'miracle' horsepower. I did it because I really don't need it, it cleans things up, and I can run a bunch of wiring under the plenum now.
Also, another issue. I don't believe it to be associated with the EGR, because it ALWAYS did this. If its idling, and I hit the gas, it hesitates, then revs up. I'm thinking vacuum leak, but I haven't come across any. Initial timing is set to 6* BTDC. Any thoughts on that?
Thank you for any information you can provide. If you need me to elaborate more, please let me know. I' not very good at explaining things by writing them out
#2
Race Director
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Hey Guys, (Sorry for the long post)
I have a 1980 Camaro with an '86 Corvette L-98 and 700r4.
Recently I had the intake apart, and decided to remove the EGR valve, and all associated plumbing. My issue now is that when it warms up (as soon as the fans kick on) it idles like complete crap. It'll drop to around 400rpm, and then back up to 1000, and back down. Back and forth, and it generally stalls out. I'm assuming it is going into closed loop since it warms up, and is looking for the EGR. Is this a safe assumption?
I know I need to get the computer re-tuned for the removal of the EGR. I just want anyone's opinion on if this would be the cause of it, or maybe something more. I have a Painless wiring kit, and it came with a check engine light module that is mounted near the steering column. When it starts to idle like this, the light DOES NOT come on. That's making me nervous.
Note: I didn't do this for 'miracle' horsepower. I did it because I really don't need it, it cleans things up, and I can run a bunch of wiring under the plenum now.
Also, another issue. I don't believe it to be associated with the EGR, because it ALWAYS did this. If its idling, and I hit the gas, it hesitates, then revs up. I'm thinking vacuum leak, but I haven't come across any. Initial timing is set to 6* BTDC. Any thoughts on that?
Thank you for any information you can provide. If you need me to elaborate more, please let me know. I' not very good at explaining things by writing them out
I have a 1980 Camaro with an '86 Corvette L-98 and 700r4.
Recently I had the intake apart, and decided to remove the EGR valve, and all associated plumbing. My issue now is that when it warms up (as soon as the fans kick on) it idles like complete crap. It'll drop to around 400rpm, and then back up to 1000, and back down. Back and forth, and it generally stalls out. I'm assuming it is going into closed loop since it warms up, and is looking for the EGR. Is this a safe assumption?
I know I need to get the computer re-tuned for the removal of the EGR. I just want anyone's opinion on if this would be the cause of it, or maybe something more. I have a Painless wiring kit, and it came with a check engine light module that is mounted near the steering column. When it starts to idle like this, the light DOES NOT come on. That's making me nervous.
Note: I didn't do this for 'miracle' horsepower. I did it because I really don't need it, it cleans things up, and I can run a bunch of wiring under the plenum now.
Also, another issue. I don't believe it to be associated with the EGR, because it ALWAYS did this. If its idling, and I hit the gas, it hesitates, then revs up. I'm thinking vacuum leak, but I haven't come across any. Initial timing is set to 6* BTDC. Any thoughts on that?
Thank you for any information you can provide. If you need me to elaborate more, please let me know. I' not very good at explaining things by writing them out
Hesitation cold probably be seen on a datalog also. Maybe a lean spot or a simple TPS setting. Tunerpro RT can be your friend.
#3
Heel & Toe
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Good idea! I have thought of doing this before, but then completely forgot about it. I'll definitly look into it.
#4
Drifting
I don't think its looking for EGR and running bad because of a lack thereof. It sounds like a vacuum leak or an IAC issue . I agree with Jack, log it and find out why. My '86 EGR is blocked and she idles rock steady and doesn't hesitate at all.
#5
Race Director
Is the engine stock? Has the ECM been altered from stock programming?
When you said "you didn't need the EGR", do you know what it does?
When you said "you didn't need the EGR", do you know what it does?
#6
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EGR is only called upon by the ECM during cruising operation and when the engine is heated up in closed loop, if you are not above a certain throttle position, I think 70%, it is not called open. I forget the temperature cutoff now, but I think coolant must be like 160-170F.
It sounds to me like you have a serious vac leak.
It sounds to me like you have a serious vac leak.