Garth S

... As Jim said as well ( post #25): agreed that a rich condition could also cause the symptoms described; however, I stupidly believed the data in post #3 - which clearly indicated a lean condition ... Only believe X% of what you read ...

Bill Ball

He says things are worse w/o the aftermarket chip. So, it's relatively dead off the line. Cam timing. Dunno.

Loaded

When i drove the car the first time my forst inclination was EXACTLY this! Cam timing. then i thought maybe it was ignition timing etc. etc. the timing chain ws just done less the 2k miles ago.

My second inclination was injectors etc.

But honestly i wont ever know until make small adustments. I am getting an X pipe and that will do one of two things

the x pipe will clean up a rich condition
or
it will make it worse.......
How else can i get this info on the mixture ratio on the fly?

Bill Ball

Timing BELT, not chain. In general, this has no effect on cam timing, UNLESS they put the new belt on the cam gears off a tooth or two OR they replaced the cam gears and were not careful about getting them back into the same position.

The ignition timing is fixed and set by the EZK brain. No adjustment. But if the cams are off, the timing is off relative to TDC, as you see the distributors run off the cams.

To get mixture information you can install a AFR meter.

Loaded

Another clue maybe, Havent driven rebecca in three days, Last night I fired her up and she immediately went to 11-1200 RPM and would not drop until about 3-4 minutes after that when i pulled in to a parking lot waiting for a friend it was surging RPM was bouncing from 500-750 aprox... it never stalled at all but it always surged.............

John Speake

For the first couple of minutes after a cold start the car is running open loop. So at that point you are very reliiant on the MAF calibration.

The idle is jumping around because the idle loop isn't able to allow the correct amount of bypassed air into the engine to keep the rpm down (or up) enough to get balance in the loop to keep the idle at 675rpm.

When the car gets onto the O2 loop, problems with MAF errors, and small inlet leaks are somewhat compensated for.

Check carefully there anen't any inlet leaks, check inlet vacuum. Try a MAF swap for a known good unit.

Daniel Dudley

Oil from a K&N filter has been known to contaminate the hot wire on the MAF. They also wear out over running time, particularly when the car is started a lot. I had my car to several mechanics who could find nothing wrong, but the dyno doen't lie.

Loaded

This is funny of sort I went ROG100 house and the first thing he did was rip out the KN filter the PO installed......

ErnestSw

I have a spare MAF you can try.

Loaded

doesnt that require manifold removal?

ErnestSw

Nope, the MAF sits under the air box at the back of the engine right below the air filter.

Loaded

phew! ok You know I would like you to drive it if yo dont mind? It is an AUTO and you may get used to the comfort of an auto tranny LOL

ErnestSw

Any time.

John Speake

Band new K&N are usually OK. The problems come when people clean and re-oil them. Then they often get overoiled, and that messes up the MAF.

SwayBar

As someone else stated, it sounds like the car is starting off in 2nd gear, which is 'normal' for the 928 autos. I would make absolutely certain which gear the car is really in when conducting the tests.