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

Intake problem? Sensor?

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Old Sep 3, 2002 | 10:52 AM
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85z51vette's Avatar
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Default Intake problem? Sensor?

When I attempt to quickly rev up the engine from an idle, there is a delay from when I apply the gas to when it actually begins to rev. Once the engine RPMs are up from idle it revs up fine. Would this have anything to do IAC adjustment? TPS? Thanks in advance guys/girls! :cheers:
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Old Sep 3, 2002 | 01:21 PM
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Default Re: Intake problem? Sensor? (85z51vette)

Man I tell ya... the '85 model must be plagued. I am having the same problem... sort of. Mine did exactly that... and I upped the fuel pressure to about 44-45psi (vacuum hose off). But I run an Ed Wright Chip... and he told me to put it there.

Now mine does it going down the road... sitting still is fine... but as I give it gas... it starts to choke. Read my post just a few below yours.... I went into a lot of detail on my problem... and what I have tried to fix it with.

here's the link if it works...

http://forums.corvetteforum.com/zerothread?id=379393
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Old Sep 3, 2002 | 02:11 PM
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Default Re: Intake problem? Sensor? (85z51vette)

So youre gettin poor throttle response.

Check the plugs/wires, clean the IAC and TB, reset the TPS and look for vacuum leaks.

Also when was the last time you cleaned your air filter, if its really dirty the same thing can happen.
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Old Sep 3, 2002 | 06:43 PM
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Default Re: Intake problem? Sensor? (vader86)

Could it have anything to do with programming? I had a custom chip done by Marcho here on the forum. Maybe something else he could modify for me?

My car runs awesome on street. I give it gas and it pulls hard. Real strong. Its just the off idle thing that bugs me. Keep the suggestions coming!
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Old Sep 3, 2002 | 07:33 PM
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Default Re: Intake problem? Sensor? (85z51vette)

Check the TPS at base idle (i.e. 450rpm); try setting the base TPS to 0.65Vdc. The ECM won't throw a code till above 0.67Vdc. This gives a little better "pump shot" as well as a slight ignition timing increase.

Check base timing; increase it till a scan tool shows the ECM is pulling timing due to knock counts.



[Modified by 65Z01, 5:34 PM 9/3/2002]
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