Idles fine, runs rough -- need advice/reassurement. Pix!
 

Important parts in bold for the impatient.

My car has been down for awhile -- I needed to replace the water pump, so I figured it an opportune time to take out A/C, P/S, get all new belts and hoses, send my injectors to Cruzinperformance, and do a general thorough cleaning. I've got some pictures attached to show ya what I mean.

http://people.ku.edu/~volaju/before.jpg

This is what the car looked like when I bought it over the summer.

http://people.ku.edu/~volaju/after.jpg

This is how it looks after cleaning it.

OK, so on to the problems--

Reassembled everything yesterday. Tried to start it, it ALMOST fired but wouldn't go. Figured it was flooded and so I gave up for the day.

Today I unflooded the engine, and put some oil in the spark plug holes. It still took about 5 minutes of trying to start it, but it finally fired, much to my delight.

Now, here's where it gets confusing. The idle is fine. It's great, actually. I figured I was OK to head off to my brothers so I could use his garden hose to flush my cooling system (this still needs to be done). I take it out on the road and, man, wtf? It just drives awful. Stumbles, dies when I let off the throttle, dies when I came to a stop. Once I got over 5k RPM, it would run better and wouldn't die if I let off the gas.

FYI: compression was 105 PSI on both rotors before I disassembled everything. I havent checked it since then, though I will next time I'm at my house just to rule that out.

Now, before I get yelled at to search -- I need to know what to search for! I need ideas what it could be. I read a thread where someones 7 ran like shit after he had his injectors serviced by cruzinperformance due to non-OEM pintle caps. Could that be a problem? When I had the fuel rails bolted back down, I noticed one of the primary injectors could twist around freely where it sits on the block, whereas the other injector couldnt. Same with the secondaries. Is that normal?

Now, for the reassurement part. Two issues:

1. when I realized I couldnt make it to my brothers, I pulled back into my house and coolant started flowing back into the overflow reservoir. I drained the coolant from the engine block in order to change the water pump, so before starting it today I filled up the rad with coolant as much as it could go. Also, I didnt bleed it. No coolant was leaking anywhere from what I could see, and my thermostat/rad cap/hoses are all new. Is it likely this is due to air in the cooling system, since I didnt bleed it, and there wasnt that much coolant to begin with?

2. I removed the water pump housing to apply a new gasket, etc. Afraid of breaking the OMP lines, I loosened the bolts that secure the OMP to the block -- then decided instead to just unbolt the banjo bolts that secure the lines to the OMP. Should I get a new gasket for the OMP-->engine? I didnt knock it off, but like I said, I loosened the two top bolts. Could that be related to my aforementioned problems?


Thanks a lot guys -- and oh yeah, manual steering feels SO much better on this car.

ECU throwing any codes? It's an S5 right? Kind of sounds like the car is in "limp home" mode. Maybe a problem with your OMP. I could be totally off, but it's worth checking out.
-John

Hmm. Yeah, it's an S5 N/A. the CEL is on, but coincidentally my intake air temperature sensor prongs broke off -- so I was expecting the light to be on. I ordered a new sensor, but it'll be a few days before it gets here.

I'll have to check the code and see what it brings up.

Sounds like a plan, let us know what you find out.
-John

Anyone else have ideas? I dont think it's in limp mode b/c it made power past 5k, and when driving had a real hard time running at any RPM under 5 -- limp mode is supposed to get you home.

I don't have internet access at my house so I'm trying to get a list of things to check for when I go back.

Tps

That's what I was thinking at first -- but it was perfectly fine before all of this and I never messed with any of the settings. Can it just become misadjusted like that?

I second that.
Had the same symptoms as you, runs well when on the throttle but once off of the pedal, idle would dip up and down from 750 till it died. It looks like my throttle doesnt close at the exact same position all the time, giving me 2 lights on my checker lamp some times. I reajusted my tps and now its all better, though I still need to clean the throttle some way.

not usually but it can suddenly fail. People here seem to think mine has...

but come to think of it, I DID just get my injectors cleaned. perhaps it's just running way too rich b/c the TPS was previously adjusted for my "dirty" injectors?

Either way, checking the tps settings wont hurt.

Update: TPS resistance was at 4 ohms. I don't know if this had anything to do with getting my injectors cleaned, but alas, I set the TPS via factory specifications and now everything is fine.

4K ohms, I mean