Strange engine

[802mx3]

I'm having this issue with my engine surging. Almost as if it had massive turbo lag. Its not all the time, and seems to do it mostly on cold starts while driving before normal operating temperature. I'm sure this has something to do with my some what crazy idle situation. That seems to be getting better and not jumping all over the place like it was. This has only started less then a week ago and its really puzzling me.

What I did that may be involved:

- new cap
- new rotor
- new Denso TT plugs, gaped to .040
- cleaned the MAF
- cleaned the throttle body
- degreased engine
- added 104+ octane boost with tank of 93 octane to clean out the system
- replaced negative battery terminal (yes its very tight)

Thats about it. It was shortly after that the car started acting like a big turbo car. (lag wise)
Idle goes from sitting at around 1500 when i come to a stop the dies down to almost stall RPM. Then will some times just surge. The strange thing is the wait, wait, wait woooooooow!!!!!! Up to 7000RPM in no time.
Not sure what that could be.

[Ryan]

holy crap.

Everyone has this problem, but not so severe. It does redline for you? Thats no good at all. It can't possibly do that without the throttle being mostly open, maybe your cable/linkage is sticky.

You most likely also have an intake leak. Let it sit and idle and spray something flammable (propane, carb cleaner, brake cleaner) around the intake and see where it jumps.

Not sure what else could cause it to be so messed. Throttle position sensor maybe? I doubt it was designed to ever be able to fault-open, but its worth a check. Did you take it off when you cleaned the TB?

[802mx3]

well I did adjust the throttle cable because there seemed to be some slack . I quickly put it back to factory location. I did notice today that my intake boot is all cracked and it looks like the PO tried electrical tape in a few areas. I'm going to gettomods.com and picking up some electrical tape my self.
I'm going to try wrapping a few times and using a heat gun. This will only be temporary until I get a real intake kit of some kind. So I'll see if this fixes the problem.

[SuperK]

If I were to troubleshoot the car, i would go in these steps:

Check engine codes, fix accordingly
Check all vacuums, make sure there's no leaks.
Air filter clogged?
Unplug O2 sensor, note any changes with it unplugged
Test TPS
Test spark intensity (little 3 dollar tool at your auto parts store)
Test fuel pressure
Test compression
check sparks for sign of odd wear (burning too rich? lean?)


what it SOUNDS like is it's possible you did an oopsie with the MAF. It might be getting stuck at certain points, causing it to stall out (shut) or high idle.

[Dark_Rider2k3]

when my VAF went out (due to carelessness that i won't do again), it didn't cause the car to surge. It caused it to sputter and choke and die off randomly.

[802mx3]

I'll check codes tonight. Checked vacuume lines and all are good except the actually intake boot. I was wondering myself about the MAF. All I did was clean it with MAF cleaner. Car was not doing any of this before all of this stuff.

[802mx3]

Fixed the idle problem, now my exhaust manifold is cashed! The whole thing is crap. Wicked loud and not worth fixing or replacing with a used one. Would like to get an actual performance header but, go figure there isnt one for my car. I've got to be honest and say that is a little ridiculous. What can be done? I've heard of using a 2.0 probe header. Did a search and couldnt really find a step by step on it. Anyone have any idea?