Surging problem

[kennyz]

Yes, My 2000 SSEi has the dreaded surging issue. However, it will do it in Drive as well as overdrive.
Also, I don`t necessarily need to be going uphill. it happens quite often as I enter the highway and go to accelerate into traffic. By letting up a little on the gas or letting it shift up, it alleviates the problem.
It pulls strong from a dead stop right up to redline. Only seems to do it if I try to accelerate as I`m moving along(ie. if I decide to pass someone}.

New plugs, new wires, new coils, used replacement module(off a properly functioning vehicle).

Any ideas?? Something else I should be looking at??

[Archon]

Over the years, I've had that happen twice. The first time was caused by a vacuum leak in the boost control actuator. So, you may want to check for vacuum leaks along that line, including the T in the LIM under the supercharger snout. The second time was caused by a bad MAF. Try disconnecting that to see if it helps.

[maxi426]

Surging, or misfire? Like Archon said, vacuum leak or try cleaning MAF sensor.

[kennyz]

Surging, or misfire? Like Archon said, vacuum leak or try cleaning MAF sensor.

Not a misfire. Definitely surging.

[kennyz]

I disconnected my MAF sensor to see if that was the problem. Although it still surged slightly, it wasn`t nearly as pronounced as when it was plugged in.
Also, it didn`t want to idle and even stalled once as I slowed down to stop.

If the MAF is bad, will the car still surge with it disconnected?

Also, with it disconnected, it didn`t turn on the check engine light. Is this normal?

[maxi426]

It could still surge some with the MAF disconnected, but it's interesting that it acts differently. PCM reverts to a back up speed/density strategy when it doesn't see the MAF. Much more accurate with the MAF working properly. I'd still try cleaning it carefully with a Q-tip and MAF cleaner.

[96 SSEi]

when I unplugged my 2000 ssei maf, i threw a po102, iirc - maf low circuit or the like so yes it should trigger a code

[MKMike]

IIRC, it will not make the check engine light come on until 2 ignition cycles of being disconnected.
As for cleaning the MAF, I've always done it without touching the very delicate sensor wires by just spraying them repeatedly, from different angles when possible.
This article should be helpful in tracking down the root of the trouble.
http://www.autoserviceprofessional.com/ ... rge?Page=1

A PCV valve, if it's sticking open causes surging, because it is causing a vacuum leak of sorts.
See for some more info http://www.freeasestudyguides.com/pcv-s ... blems.html

Since there are so many potential causes of surging, I'd start by addressing the maintenance items first, since they are typically inexpensive and should be done regularly anyway.
Those include the PCV valve and the fuel filter.
As Archon mentioned, vacuum leaks are always a strong possibility.
Besides the vacuum T beneath the supercharger snout, the metal tubing from the egr can develop splits.
An inspection mirror will help see a split underneath.

A fuel pressure gauge will enable you to troubleshoot fuel delivery issues.