01 SE 3.1L intermt. fast idle & no pickup

bombergp · 10-22-2007, 08:04 PM

At 78k mi. I just had upper/lower intake gaskets done, also 1 cracked injector. Right when I got car at mechanics lot it would race in idle 2000-2750rpm. Lunch time nobody to recheck it. 3rd time I restarted motor, it settled down. Its not cold outside, 70deg. Next trip 30mi same racing idle, shut off 3-4 times after running 1-2 min. each time, get going and sluggish performance also shifting early! Is the new injector on #1 cyl. crap? The battery was disconected, wrong time. Does the injector need programming/resetting? The car ran good before this shop FIXED it. Service Engine Soon lit up when I got home.

tblake · 10-23-2007, 12:09 AM

sounds to me almost like there is a vacuum leak. Mayby try and listen for one while the car is idling. Myself, I would take it right back to the shop and have them fix it again.

bombergp · 10-23-2007, 12:30 AM

Hey Tblake, I started her up tonight, same thing 2000rpm. Shut it off and looked for loose hookups etc. Found one half on vac line near the coil packs, pushed it further and also the flexible connections at air filter box slightly not 100%. Result, start up goes only to 1500rpm and drops to 900rpm in 45 seconds. Driving it, acceleration good but shift points go from short/early to late/high rpm 3500-4500 1-2 gear. At 35 mph I take foot off and it will stick like on cruise, 40 mph and it slowly accelerates to 50mph(foot off gas). Is this the TCC solenoid? How much is it to fix? Thanks for your response.

tblake · 10-23-2007, 01:20 AM

It could be the TCC. Was it doing this before you brought it in for a lower intake job? If not, take it back and have them fix it (FREE). It is also possable that since the battery was unhooked that it may need time to relearn its parameters. You might just want to drive it for a week or so and see if it fixes itself. Drive it like you normally would.

bombergp · 10-23-2007, 07:41 PM

Tblake, it sure as crap wasn't like this before they worked it over, but I bet he'll find some bogus fault to charge me on repair & parts. Do scanners only pick up codes when SES is lit? Should I try disconnecting battery for 24 hrs?

tblake · 10-24-2007, 02:09 AM

no, just leave the battery connected. Lets go over this again. Start car (high idle problem is fixed, right?) Put in Drive. hit gas, what happens? 1st to second is early and then 2nd to 3rd is late? Then what? 4th ok? do this.... Get the car nice and warmed up, take in on a road and cruise up to 55mph, make sure its in od (rpm's about 1700) while keeping your right foot at a steady position on the gas, use your left and tap the brake pedal, dont apply the brakes, just tap it enough to see if the RPM's shoot up to 2000 (torque converter unlocking) and then let off the brake right away and the rpm's should go right back down to about 1700. You can do this a ton of times just to work the TCC soloniod and circuit. If everything goes like i said, its safe to say that the TCC is just fine.

I've had a ton of these 3100sfi's apart for lower intake leaks. You said you found a vacuum leak underneith the coil packs? Was this the line that goes to the fuel pressure regulator? Because if it is, and it wasnt pushed on the manifold far enough, chances are that this line still isnt correctly hooked up to your MAP sensor (might be the cause of your irratic shift points). I would just take the sensor off (two 6 or 7mm bolts i believe). Then check the vacuum line, make sure its on the manifold and the sensor all the way.

Please report back your findings. Good luck!!

bombergp · 10-27-2007, 12:21 PM

Tblake, thanks for your input. I started it up yesterday and was about to check with vacuum gage, and it just ran 1500rpm 30 sec. & settled around 900rpm. Its also just about 100mi later since shop work. I took out again for 10 mi. acelerating good still shfts 1-2 @ 4000rpm, 2-3 ok @ 3300/3500. I guess it retaught itself? Bad news,the service engine soon light came on later, at autozone nice guy scanned code, TPS. So I'm goin to get one now. One question are the wires in the tps bundle wraped with black tape that come out of the tube shield done by GM or did the mechanic do it? Wonder if he goofed somthing. It didn't do this before they worked on it, why is tps bad now?

bombergp · 10-27-2007, 09:44 PM

It's fixed! New TPS is all it needed. No thanks to the idiot mechanic when degreasing my motor he got cleaning fluid into TPS. When I removed the old sensor there was dried residue in the throttle housing, must of used a pressure washer! Skimpy o ring can't keep that out!
I had to run the engine & shut off 4 times to get proper idle speed after installing it. Test driving, it shifts at original points again, throttle response too. I bet if I took car back to shop right away they wouldn't have admitted fouling the TPS themselves during degreasing, just happy to charge me for another repair!

tblake · 10-27-2007, 11:20 PM

Well, alright, Problem solved. Good work!!!!

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