Running issues
Running issues
Put my intake on, and to my knowledge everything has been properly connected. The car runs rough and idle's low, has occasional misses. Almost behaves like there is a massive vacuum leak or the cam timing is off. I just did the guides and had to re-time the right bank. Any other ideas? Thanks guys!
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Re: Running issues (jimbyjimb)
Measure the actual ignition timing................we seen lots of home/incompetent mechanic retimes which were off a tooth..............easy to do wrong.
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goody90q45
- Posts: 3679
- Joined: Wed Aug 17, 2005 2:07 pm
- Car: 1992 Infiniti Q45 (sold)
- Location: Orangevale, CA
Re: Running issues (jimbyjimb)
When I put my intake back on my 90Q a month ago I forgot to connect the 3/4" hose under the intake tube that comes out of the valve cover. The engine would barely stay running. Once I realized my mistake and clamped it on all was well. It would be easy to forget to connect a hose during the plenum reinstallation.
It sounds like you do have a vac leak and my suggestion would be to examine the 4 or 5 hoses feeding directly into the intake tube. Are they cracked in the body or on the ends and are they all connected and clamped? One leak in any of these 5 hoses or others feeding them will cause major idle and acceleration issues. Try and trace each system, especially the large diameter hoses. The same hose I just mentioned feeds to other hoses the other end of the plenum via the 1/2" diameter tube attached to the underside of the plenum and is easy to check.
If you can't find anything obvious, and can somehow get your engine to run at a steady, low idle, start squirting with a can of brake parts cleaner looking for a change in idle and pointing towards a leak. Tedious but it works.
The two IAC hoses along the firewall are a PITA when reinstalling the plenum and the 1/4" pressure regulator hose right next to it has given others trouble. Go back and recheck all 3 with a flashlight to make sure they're on correctly.
It sounds like you do have a vac leak and my suggestion would be to examine the 4 or 5 hoses feeding directly into the intake tube. Are they cracked in the body or on the ends and are they all connected and clamped? One leak in any of these 5 hoses or others feeding them will cause major idle and acceleration issues. Try and trace each system, especially the large diameter hoses. The same hose I just mentioned feeds to other hoses the other end of the plenum via the 1/2" diameter tube attached to the underside of the plenum and is easy to check.
If you can't find anything obvious, and can somehow get your engine to run at a steady, low idle, start squirting with a can of brake parts cleaner looking for a change in idle and pointing towards a leak. Tedious but it works.
The two IAC hoses along the firewall are a PITA when reinstalling the plenum and the 1/4" pressure regulator hose right next to it has given others trouble. Go back and recheck all 3 with a flashlight to make sure they're on correctly.
Re: Running issues (goody94q45)
Thanks for the advice guys. I'm pretty sure I have the timing marks lined up correct, but I will check the timing. One of the IAC hoses that I made is a bit too long and looks almost kinked, so that could be it. I'm pretty sure I hooked all the hoses up but I will check again. Ick. I really appreciate the input.