surging @ 2k-2700 in my 2.0 Options

[4WheelDrifter]

While cruising (steady throttle) from 2000-2700rpm in any gear, I get "surging" from the engine, like it doesn't know if it wants to accelerate or slow down. No backfires or anything. If I hit the gas, it pulls hard and smooth. Runs fine at steady throttle in the rest of the RPM range.

BTW, It's a 2.0 4cyl with FI, newish vac hoses, Web cam with stock profile and that "GT" 4 pipe muffler everyone loves. (IMG:style_emoticons/default/rolleyes.gif)

Any ideas of what it could be? From my knowledge, it seems like it's a lean condition but what's the fix?

Thanks for any info. (IMG:style_emoticons/default/clap56.gif)

[ArtechnikA]

While cruising (steady throttle) from 2000-2700rpm in any gear, I get "surging" from the engine, like it doesn't know if it wants to accelerate or slow down. No backfires or anything. If I hit the gas, it pulls hard and smooth.

check the TPS; probably got wonky contacts at the throttle position used for cruise at that rpm.
you can unplug it and test. it will have zero accelleration but you're just checking to see if the cruise surge condition is improved once you get it there. there are visual (internal) tests and some checks you can do with a multimeter.

could also be a dizzy advance issue but i doubt it...

[mike_the_man]

It could be the TPS, or it might have something to do with the Web Cam. Was the engine recently rebuilt? Did the engine just start doing this, or has it done it since the web cam was installed? Did you tweak the Fuel Injection to work with the web cam? As far as I know, you will have to adjust the MPS to work with a different cam, so it could definately be lean.

[4WheelDrifter]

I just bought the car so I don't know if the FI was tweaked, I don't think it was though. I could ask the PO that had all the engine work done if it was tweaked.

Going by the receipts:

The cam is a stock grind.
The TPS and all vac lines were replaced back in 98 when the engine was rebuilt. (Hoses are still like new)
The points were replaced with the "Ignitor" in 98 as well, don't know what timing was set to.
Still using stock vac advanced dizzy.

Stock air filter still there.

[Bleyseng]

Could be..any of these as the FI has the hardest time going from idle to partload...
The TPS is worn -pop off the cover and look at the traces to see if there are big lines in them.
Check the dizzy shaft for wear- a worn out dizzy will not produce a nice clean steady mark when you time it with a lite. The mark will blur cuz the dizzy is wobbleing all over the place.
Check the FI points for wear
Check your timing

I doubt the MPS is bad but do you have the proper one for this engine??

Geoff

[4WheelDrifter]

Geoff, as far as I know, all the FI parts are proper for a 2.0. If the MPS has the # on it, I could get the part # and compare.

I hate acronyms, MPS is the pressure sensor right? (IMG:style_emoticons/default/wacko.gif)

I have a timing light, I'll give that a shot. It's been a while since I've used one though.

[4WheelDrifter]

Had a friend driving behind my 914 in his Honduh S2000. He told me the car is running really rich going by the smell. I may bring it to a shop that knows 914s to get it right. I don't have the tools, the info or 2 hands to do the work right now. I can't even put my new Optima red top in because I can't lift the old battery out. (IMG:style_emoticons/default/sad.gif)