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Discussion Starter · #1 ·
before the plethora of USE THE SEARCH FUNCTION flames erupt in an orgy of frustration, i have a similar but in its own right different problem for you guys.

the engine idle has no problems idling while driving, or coasting to a slow stop. but, in certain circumstances, the engine will bog and stall during hard braking/deceleration.

is it because the engine is being pitched forward? fuel not getting to where it should be because of inertia? any ideas?

will i ever stop typing interogatives?

thanks
 

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Try cleaning the AAC or IAC valves. Just hope you have the service manual.
 

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Mine was doing the same 'exact' thing.

I had to recheck my base idle. It was set at 450 rpms. I had never checked it before and on hard deceleration or when my AC compressor kicked in the car would bog and almost shutdown.

The ECU was adjusting for it and the idle would always appear to be fine at around 850 rpms.

I readjusted the base idle to around 750-800 and the problem has completely gone away.
 

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Discussion Starter · #4 ·
how exactly would one tinker with the idle? have a shop mess with the ECU?
 

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WolfInSheepsClothing said:
how exactly would one tinker with the idle? have a shop mess with the ECU?
Nope! It's a DIYer! A write-up is on www.se-r.net...

Idle Speed Adjustment
By Rob Microys


--------------------------------------------------------------------------------

I would just like to update those who have idle speed adjusting woes. For a while since I had an idle speed adjustment problem just after I cleaned out my throttle body. I had to adjust the throttle screw all the way down. I had thought that I was adjusting the idle correctly with the TPS disconnected. But I had missed one important thing. I didn't stop the car before disconnecting the TPS. This is VERY important!

So for those of you who have their idle screws turned all the way down, I'm thinking that your engine idle speed was improperly set at some point in time. To properly set the idle speed, do the following:

As per my Nissan manual, it says something like:

1. Warm up car properly... a short drive is best.
2. Run engine at about 2000 rpm for about 2 minutes under no-load. Rev engine two or three times under no-load, then run engine at idle speed for about 1 minute.
3. TURN OFF ENGINE, disconnect TPS, start engine.

Personal comments. My car at this point would turn over and fire up but not run. I adjusted the screw upwards until I could start the engine such that it did not stall out.

4. Rev engine 2-3000 rpms 2 or 3 times under no-load, then run engine at idle speed.
5. Check base timing 15 +- 2 deg BTDC, adjust if required. (Mine was bang on 17 deg)
6. Check idle speed, should be 750 +- 50 rpm. If no good continue on else go to 7. Rev engine 2 - 3000 rpm rpms 2 or 3 times under no-load, then run engine at idle speed. Adjust screw go to 6.
7. Turn off engine, reconnect TPS, start engine.
8. Rev engine 2-3000 rpms 2 or 3 times under no-load, then run engine at idle speed.
9. Check idle speed, should be 800 +- 50 rpm. If at this point your idle isn't correct, there are some other components which should be checked which include (IACV-AAC valve, IACV-AAC harness and the ECM)

I know that others on the list have mentioned the fact that their cars have this symptom, and this might be the cure.
Here is the link to the procedure:
http://www.se-r.net/engine/adjust_idle.html
 
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