Intermittent symptoms: Check engine light, BAS ESP light, ZERO throttle response.

2 independent mechanics have said that they are unable to reproduce the problem. Said the car runs like a champ for them. Except I don't think they really understand how she feels to drive when she's actually running right. Supposedly all trouble codes were unrelated and addressed. I've already spent a ton of money.

When this weirdness happens, as it did again this morning on my way to work, I can put my foot to the floor and count 3 alligators with no increase in speed. At all. Even when this weirdness doesn't seem to be happening, the car still lacks the crisp response I'm used to. I'm driving like a little old lady because I have no confidence in my acceleration to maneuver in traffic.

I'm willing to put the car in the shop one more time and then I'm giving up on her because she's just no fun anymore. 103k on the clock and meticulously maintained. Please tell me what to have them check and in what order. I want my little rocket back.

 

The first thing I would try is a throttle reset, cost nothing.

 

These symptoms can occur when the alternator is barely working and can't supply enough current at any speed over idle.

Les

 

I had similar problems on a car when the fuel pump was failing, not enough fuel being supplied to satisfy the needs of acceleration, as the pump was fluctuating in speed. Or in your case the fuel filter could be failing as the pressure regulator may be not keeping the pressure up to spec.

 

Key is to instrument and keep a running log file of the various parameters that could cause the problem. Most of the possible sensors have already been listed.


What you need is a mini Bluetooth OBD-II dongle, an Android smart phone or tablet, and the Torque Pro app. It can be set to record quite a few parameters is a .CSV file about once a second.


Just need to keep it running until it happens, then review the parameters around that time. Something is going wonkey.


Is a lot easier now than when we needed a mile long corridor to unroll the Brush charts of a flight to find anomalies.

 

Does this mean the BAS/ESP light is out now?

Just thinking outloud here, if the car thinks the braking and traction control system has a problem would the computer allow the supercharger to kick in?

 

Could be the throttle pedal potentiometer or even the throttle body or the connection pedal->PTCM->throttle body..
Like, PTCM does not see changes in throttle pedal, or if it does, maybe it's commands to the throttle body are being ignored ?

 

Don't give up on it, with a little patience and help from the forum, you can do it.

 

Is there a reason you are not willing (or can't find a 15 year old nerd) to instrument it ? One of the things you can monitor is the throttle position sensor and that will tell you quickly if the signal is getting to the computer. You can also compare the TPS to the actual throttle opening to see if the throttle body is matching your request.


Sounds like people have just been throwing parts at is and that is not the way to diagnose a computer car.

 

So what code did the CEL display? You can at least tell us that.

 

I'm adding all the items you guys have mentioned to a list of things for the mechanic to check when I put the car in the shop later this week. The BAS ESP comes on when I try to accelerate any harder than granny mode. It goes away once the engine is shut off. The CEL is on all the time. The only codes that came up previously had to do with O2 sensors which were replaced in order to pass the California smog test. Thanks for all the ideas so far.

 

I am no mechanic but suggest you rule out a bad battery and a common ground. For sure search the forums. Each of these problems have been solved for others. In example:
[I]
Here's the kicker, even though the switch was indeed bad, that wasn't what was causing the random BAS light. It's the fuse panel/headlight switch. My trusted sidekick (my 7 year old son) and I diagnosed a faulty connection at the fuse panel, specifically the number 2 fuse which is for the brake lights and cruise control. There's enough wiggle on that fuse for it to loose contact and cut off cruise and brake lights. We figured this out with the car running, my sons foot on the brake pedal, and me moving the fuse around. The further in you push the fuse, the worse the connection. It's the same if you wiggle in the upward position. I'm pretty confident fuses aren't meant to wiggle. So, i plan to remove the headlight switch and see if it can be saved or not.[/I

It has been a while but I seem to recall a loose wire at the upper rear of the engine block which tripped an intermittent Check Engine. Just securing it was the fix. My crank shaft position sensor gave me some odd performance issues on its way to failure. The fix was quick and cheap.

It will be fun again.

 

Did you have a resent oil change & do you have the stock air filter setup?
I am asking because I got my wifes crossfire cheap as the chevy dealer who took it as a trade, couldnt fix a similar problem. They did not set the filter cover back in place correctly.
And there was a gap between the filter housing & the throttle body. Had similar problem to yours & you really had to look to find it.

 

I did get the oil changed recently and yes, everything is bone stock. I'll add the filter cover to the list of things to check.

I was planning to put her in the shop today but for the first time in more than a week, she ran just fine on the way to work this morning even though the CEL is still on. I drove to the bank at lunch, still running great.

So frustrating.

 

With fingers crossed, I finally put my car back in the shop this morning. I've been driving it for about 3 months with the same intermittent problem because a bunch of stuff came up and I kept procrastinating. The mechanic just called. He said it was a fuse.

 

I am having all of the same issuses with my car as well.. my SC is not working at all either.. not even on cold starts

 

After further diagnostics, they say it was a faulty relay that blew the fuse and it's being replaced right now. Do they mean the RCM? I'll have to ask when I pick up the car later today. I sure hope this is it so I can get on with the cosmetic restoration I started in March.

ETA: Yes! I've got my car back and it's fixed. I almost forgot what it feels like. It was the RCM. The burnt contact was plainly visible.

 

Super charger coolant pump and pig tail. That's your problem

 

SOLVED a week ago Robbie!


HUH? Again, SOLVED a week ago...