Car won't rev up. Hitting low rev limiter

echostats · 08-27-2008, 08:19 PM

Hey guys, after searching a lot on the forums I have decided to make my own thread. I took a video (it's sideways but it works, click the link).

As you can see, the cars seems to be hitting a low rev limiter or something.

Here's what I have done so far:

1. Checked for boost leaks, there are none
2. Tested ohms on injectors all the same (2.3), checked wires and replaced 7ES plugs
3. Checked waste gate
4. Tested TPS, set TPS
5. Checked o2 sensors
6. Checked fuel pressure
7. Checked the MAF connection
8. Replaced the CAS
9. Coolant level is perfect
10. Swapped ECU

Please help!

UPDATE: Not only does the tach jump when parked, but while driving the car feels like it's hitting fuel cut at 5k RPM (10lbs boost). It shakes wildly. I have checked the fuel pressure and it's fine.

Defiant · 08-28-2008, 06:24 AM

You'll find "something" first.

echostats · 08-28-2008, 06:47 AM

Quote:

Originally Posted by Defiant

You'll find "something" first.

I'm not sure what you mean.

lq1driver · 08-28-2008, 07:53 AM

my car did this once it actually ended up being that the contection at the maf was loose check your conection

echostats · 08-28-2008, 08:00 AM

Quote:

Originally Posted by lq1driver

my car did this once it actually ended up being that the contection at the maf was loose check your conection

Sadly, I have tried that. Because of all the boost leak tests I have done, that whole intake pipe + MAF has been off several times. I have had MAF problems with past DSMs so that was the first thing I did was unplug and plug it back in snug.

lq1driver · 08-28-2008, 08:34 PM

your not far from me if you can drive it up and ill help you take a look at it have you checked and tested the coil pack

echostats · 08-28-2008, 08:38 PM

Quote:

Originally Posted by lq1driver

your not far from me if you can drive it up and ill help you take a look at it have you checked and tested the coil pack

Thanks for the offer. I may just take you up on that if I can't figure this out.

I am going to replace the CAS here in the next couple days just on a hunch. I will report back.

Defiant · 08-29-2008, 04:14 AM

Quote:

Originally Posted by echostats

I'm not sure what you mean.

Now you know how I felt when I read about your "low rev limiter".

echostats · 08-29-2008, 05:37 AM

Quote:

Originally Posted by Defiant

Now you know how I felt when I read about your "low rev limiter".

I know it's not possible... I was describing the sound. Watch the video and you'll see what I mean. Just trying to fix my car dude.

lq1driver · 08-29-2008, 01:47 PM

i just realized you have afc im not to familiar with it but is it possible that its not supplying enough fuel on your top end? do you have a wide band or data logger to see whats going on

echostats · 08-29-2008, 02:12 PM

Quote:

Originally Posted by lq1driver

i just realized you have afc im not to familiar with it but is it possible that its not supplying enough fuel on your top end? do you have a wide band or data logger to see whats going on

Now that would just be too easy. Remember, we are dealing with DSMs here. The car has been decently tuned with a logger/afc and ran perfect for weeks (months?) and out of nowhere this whole issue came about.

myblack98gst · 08-29-2008, 10:29 PM

just check the afc settings again make sure everything is set up for the car right I have messed with peoples afc's before just to make the car act like it is messed up so they freak out. haha

echostats · 08-29-2008, 10:35 PM

Quote:

Originally Posted by myblack98gst

just check the afc settings again make sure everything is set up for the car right I have messed with peoples afc's before just to make the car act like it is messed up so they freak out. haha

Well, to my knowledge no one has been sneaking into my car messing with my afc. And I know the general slope of my afc settings and after checking, the settings have not changed.

I would be so happy if someone would read this thread that has actually experienced this problem before.

ChltDSM · 08-30-2008, 05:43 AM

I had that problem when my water coolant level was to low and/or the water temp sender was toast or unplugged. If that sender isn't reporting water temp ot the ECU it will do exactly as your decsribing.

echostats · 08-31-2008, 09:00 PM

Quote:

Originally Posted by ChltDSM

I had that problem when my water coolant level was to low and/or the water temp sender was toast or unplugged. If that sender isn't reporting water temp ot the ECU it will do exactly as your decsribing.

Coolant level is perfect. Thanks for the idea though.

I am borrowing an ECU from a friend so I can rule out the ECU being bad.

ChltDSM · 09-02-2008, 06:37 AM

Maybe toss in a known working MAF and check the wires in the MAF harness. I had a similar ( chuggy, low rev limiterish) thing happen the other day when the 12v wire to my MAF ( GM MAF ) came loose and the MAF signal was intermitent.

Check to insure that the kharman MAF setting in active in the AFC?

Does it change when you depress the clutch? ( thinking maybe the crank angle sensor is loose or has been struck)

echostats · 09-02-2008, 06:58 AM

Quote:

Originally Posted by ChltDSM

Maybe toss in a known working MAF and check the wires in the MAF harness. I had a similar ( chuggy, low rev limiterish) thing happen the other day when the 12v wire to my MAF ( GM MAF ) came loose and the MAF signal was intermitent.

Check to insure that the kharman MAF setting in active in the AFC?

Does it change when you depress the clutch? ( thinking maybe the crank angle sensor is loose or has been struck)

Thanks for the response. I will try a good working MAF as soon as I can. I have checked the plug on the MAF a couple times to make sure it hasn't come loose but I have not yet tested the wires.

I will double check the setting in the AFC. I know which setting you are talking about but I cannot remember if it is active or not.

The clutch is making some interesting noises but I think that's completely unrelated. As far as the angle sensor, I just replaced the Cam Position Sensor. Isn't that the same thing?

lq1driver · 09-02-2008, 07:39 AM

no our cars have a cam angle sensor and crank angle but if you had a bad crank sensor i dont think the car would run but i guess it is possible i have a good working maf up here if you want to drive up and try it

echostats · 09-02-2008, 07:43 AM

Quote:

Originally Posted by lq1driver

no our cars have a cam angle sensor and crank angle but if you had a bad crank sensor i dont think the car would run but i guess it is possible i have a good working maf up here if you want to drive up and try it

Hmm... do you have an ECU I could try as well? I may just take you up on that. I will look into putting in a new crank angle sensor. Thank God for Advance Auto / AutoZone... buy it, try it, return it = great for DSMers.

cbrfrenzie · 09-02-2008, 08:04 AM

Also, you should check the clutch switch and make sure its functioning properly. Mine was slightly un-plugged and was doing the same thing. The switch that is triggered when the clutch pedal is slighly depressed, not the cruise control one when the pedal is on the floor.