Flat spot in acceleration high rpm - Toyota Nation Forum : Toyota Car and Truck Forums

crazy_camry · 07-28-2010, 12:04 PM

Hi guys. i have a 98 camry V6 5 speed. it seems between 3500-4500rpm there is a flat spot in acceleration. i've done a search and come up with a thread about the ACIS valve opening or closing at around this rpm's. what could cause this 'flat spot'?

73sport · 07-28-2010, 09:24 PM

Clean your EGR valve! It will help!

Not just the valve, but the path from the valve into the intake! If it hasn't been done in years, you can bet its full of carbon and soot! This things are depending on that working. You might also want to check for vacuum leaks too! Any other issues?

EGR Valve:

Also, take a look at this thread: Some good info!

P0401 related to Catalyst Monitoring Y/N?

crazy_camry · 07-29-2010, 10:37 AM

thank you for the reply. i'll make a day of it and clean it and the throttle body. what other things can i take off and clean?

73sport · 07-29-2010, 10:50 AM

What's the history on this car?

If you really want to make a day of it, pulling the intake plenum would be advisable. You can clean the ACIS, air intake plenum, TB, IAC, MAP (use only MAP cleaner).

Do seach for each of these. There are many DIY threads. The plenum is the hardest to clean due tp its size. Lacqure thinner seems to break down the deposits fairly well but its pretty flammable so be REAL careful.

Have you seen this: http://camrystuff.com/index.php?page=Gen3_Manuals / http://camrystuff.com/index.php?page=Gen4_Manuals
Pull up the EG2.PDF, (1MZ) and it will guide you through it.

An excellent time to replace plugs, fix leaking valve cover gaskets AND do a compression test too!

Edit, grab a new fuel filter and Air filter too!