Well, I discovered yet another issue this past Sunday afternoon. I started the car while I had the hood up and the driver's door open. After it warmed to normal operating temp, I shut the hood and the RPM dropped way down (nearly stalled). I then got in the car and shut the door and it did it again. Could this be a grounding problem? I did a search on it and nothing was mentioned about a drop in RPM in situations like this. Can someone give me a little insite on grounds and the grounding locations?

 

Weird, it sounds almost like an oversensative knock sensor. I honesty don't know, though.

 

does sound like the knock sensor, try tapping on the block with a hammer (lightly) to see if it happens then too

 

Don,

That is one weird car...I've never heard of that either. So does it level back out after the door is shut?

Tim

 

Where on the block? I don't want to stick my hand in some place and get it burned.

 

Yep. I can shut the doors, hood and hatch and the RPM will drop but then jump right back up to what it was(can't say normal cause it's still about 1200). Sometimes, it doesn't do it. I would say it does it about 80% of the time.

 

Here's another weird one (albeit unrelated). Power your windows up or down while transitioning between the 1st and 2nd turbo. The window will hesitate right at the transition.

 

No thanks. I'll keep my hands on the wheel.

 

I think the sensor is in the front of the engine, but it should pick up at rap with a hammer from any place on the block. Find a convienient place that you can tap on it...it is set to pick up knock when not under boost so it should be semi sensitive at idle. Basically the sensor listens to the engine noices for a peak bang or knock and then retards timing so slaming doors and tapping on the block can trick it into thinking it's knock.

 

i believe this is due to the stock fuel pump going into a higher output mode.

 

I am at work and dont remember exactly but I thought I saw in the manual that the fuel pump switched from low to high around 2000 rpms (or something lower than I expected). I will look it up if someone else already hasnt verified this when I get home...

Shawn
www.3rdgenrx7.com

 

Ok, I just drove the car and tried to make it do it again, and it wouldn't! I think there are gremlins lurking about!!!

 

Couldn't have anything to do with the factory alarm system and load on the electrical circuict ?????? Just a guess as electrical loads play a part on idle.

 

tap on the engine loop. The loop on the UIM were you use the chain to lift the engine.

you will see if it is the knock sensor. there is a procedure to test it, i did it once, check the manual for it, i believe you need to check the voltage somewhere in the diagnosis box

 

Yea gotta be the knock sensor.

 

wow, 2000rpm???? thats really damn low, why the hell would they design it like that?? why not just have it in high all the time?

 

Many people do convert their fuel pump to run in "high" mode.

Mike

 

Here is a pic of the knock sensor:

 

knock sensor is way off base my car did the same bad grounds. loose grounds. mine were loose behind the Bumper. took me a while to find the prob but i cleaned the connectors and tightned them down now no problems.

 

even the weldon race pumps have a manual high low swith on them... why dont we make our cars idle at 2000 rpm throttle response and boost will come in quicker..... the reason is longevity.

 

Can you give me a little insite on all the grounding locations? Also, did you replace all of them or add any additional ones? Thanks.

 

Don, some are easy to see....one on the firewall to the Upper intake manifold (easy to get to on the passenger side of car)....add one from the negative terminal to the frame rail....underneath the car, hole where you change the sprak plugs, crud gets built up there from oil changes....various grounds attached to the exhaust piping....check the ECU ground is tight (its behind the passenger kick panel (right foot side).

Tim