C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

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Old Mar 21, 2017 | 09:35 PM
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I have a 1988 Corvette and I reset the IAC. It doesn't seem to want to start now. I do know the battery is low because I've been running the fan trying to clean it out with one of those stink remover machines.
It cranks, I hoping it's just a low battery. In not any other ideas?
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Old Mar 21, 2017 | 11:23 PM
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Welcome to the forum!

The IAC (or lack of a functioning one) wont really have an effect on your car starting or not. Now, once running, your IAC will control you idle speed during warm up.

If you know your battery low, you need to get that fixed. You engine will need to spin fast enough to catch.
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Old Mar 22, 2017 | 01:59 AM
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Originally Posted by 0333griffin
I have a 1988 Corvette and I reset the IAC.
Please explain how you did that.

The IAC will be reset if you connect ALDL pins A and B together. It continuously tries to close and you can hear it clicking when it runs out of adjustment (completely closed and bottomed out).
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Old Mar 22, 2017 | 09:01 AM
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Thanks. I will give that a try.
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Old Mar 22, 2017 | 03:11 PM
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Originally Posted by 0333griffin
I have a 1988 Corvette and I reset the IAC. It doesn't seem to want to start now. I do know the battery is low because I've been running the fan trying to clean it out with one of those stink remover machines.
It cranks, I hoping it's just a low battery. In not any other ideas?
If the battery is low, you may have issues starting so you need that fully up and ready before we go further. Why did you reset the IAC?
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Old Mar 22, 2017 | 08:37 PM
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Originally Posted by aklim
If the battery is low, you may have issues starting so you need that fully up and ready before we go further. Why did you reset the IAC?
I did fully charge up the battery and it started right up.

The reason I reset it, I replaced it with a new one and forgot to set the same as the old one.

Do you have any ideas as to why I keep getting a code 32 and 33? I replaced the MAF with a new after market one last year. The code went away for a few months and then popped up again. I might have bought a cheap one.
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Old Mar 22, 2017 | 08:47 PM
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I forgot to mention other than a small miss it runs fine.
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Old Mar 22, 2017 | 09:32 PM
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Originally Posted by 0333griffin
I forgot to mention other than a small miss it runs fine.
Fix the miss and it will run great!
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Old Mar 22, 2017 | 10:47 PM
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Originally Posted by 0333griffin
The reason I reset it, I replaced it with a new one and forgot to set the same as the old one.

Do you have any ideas as to why I keep getting a code 32 and 33? I replaced the MAF with a new after market one last year. The code went away for a few months and then popped up again. I might have bought a cheap one.
You couldn't and shouldn't. It should be done by the ECM or indirectly. Pushing or pulling the pintle means buying a new one.

32 is EGR and 33 is MAF circuit. For your 33, could it be the relay maybe? I don't have an FMS for that.
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Old Mar 23, 2017 | 02:37 AM
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Originally Posted by 0333griffin
I did fully charge up the battery and it started right up.

The reason I reset it, I replaced it with a new one and forgot to set the same as the old one.

Do you have any ideas as to why I keep getting a code 32 and 33? I replaced the MAF with a new after market one last year. The code went away for a few months and then popped up again. I might have bought a cheap one.
The IAC is recalibrated by the ECM every time you turn on the ignition. You don't need to do anything else. The FSM tells you to set the length of the IAC pintle because the plastic guide will break if the pintle is extended too far when the IAC is screwed in. The pintle bottoms out and then twists and breaks the plastic guide inside the IAC.

Error code 32 is EGR SYSTEM failure. If the EGR is not working you will get this error. It is usually caused by the EGR valve not opening and the EGR thermo switch not getting hot. A bad thermo switch or broken wire will also cause an error 32.

Error code 33 is MAF signal error. It happens when the MAF is not communicating with the ECM. That's usually caused by a poor connection (corroded) on one pin in a connector, but could be a broken wire.

Last edited by Cliff Harris; Mar 23, 2017 at 02:37 AM.
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Old Mar 23, 2017 | 08:25 AM
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Originally Posted by aklim
You couldn't and shouldn't. It should be done by the ECM or indirectly. Pushing or pulling the pintle means buying a new one.

32 is EGR and 33 is MAF circuit. For your 33, could it be the relay maybe? I don't have an FMS for that.
I was reading up on that this morning. Maybe
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Old Mar 23, 2017 | 08:29 AM
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Originally Posted by Cliff Harris
The IAC is recalibrated by the ECM every time you turn on the ignition. You don't need to do anything else. The FSM tells you to set the length of the IAC pintle because the plastic guide will break if the pintle is extended too far when the IAC is screwed in. The pintle bottoms out and then twists and breaks the plastic guide inside the IAC.

Error code 32 is EGR SYSTEM failure. If the EGR is not working you will get this error. It is usually caused by the EGR valve not opening and the EGR thermo switch not getting hot. A bad thermo switch or broken wire will also cause an error 32.

Error code 33 is MAF signal error. It happens when the MAF is not communicating with the ECM. That's usually caused by a poor connection (corroded) on one pin in a connector, but could be a broken wire.
I replaced the EGR value recently and the code stayed on. The old EGR value was definitely bad. I will look at the wiring and connectors again.
Thanks
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Old Mar 23, 2017 | 09:52 AM
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Originally Posted by 0333griffin
I replaced the EGR value recently and the code stayed on. The old EGR value was definitely bad. I will look at the wiring and connectors again.
Thanks
Just for the hell of it, did you clear the code? Pull fuse to ECM or something so you can scan it and have no history codes?
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Old Mar 23, 2017 | 11:00 AM
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Originally Posted by aklim
Just for the hell of it, did yo4u clear the code? Pull fuse to ECM or something so you can scan it and have no history codes?

I did yesterday and code came right back.
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Old Mar 23, 2017 | 11:15 AM
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Originally Posted by 0333griffin
I did yesterday and code came right back.
Anyone near you that can lend you their MAF for an hour or so? I'd really hate to buy another one
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Old Mar 23, 2017 | 11:39 AM
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Originally Posted by aklim
Anyone near you that can lend you their MAF for an hour or so? I'd really hate to buy another one
That's a great idea. I will check.
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Old Mar 23, 2017 | 11:43 AM
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Originally Posted by 0333griffin
That's a great idea. I will check.
20 maybe 30 minutes should be fine
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Old Mar 24, 2017 | 05:25 PM
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Will I got it fixed today. I cleaned the throttle body and found a small air leak.
The car sounds great!
Thanks everyone for your help!
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Old Mar 24, 2017 | 09:46 PM
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Originally Posted by 0333griffin
I forgot to mention other than a small miss it runs fine.
Besides a few squeaks , rattles , and miss fires . It's a pretty good car. Lol. If I wasn't laughing, I'd be crying. 92 lt1.
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Old Mar 28, 2017 | 11:20 AM
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They are fun to drive!
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