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Car loses power sputters around 3000 rpm

 
Old 11-06-2009, 02:16 PM
  #1  
jacketfan89
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Default Car loses power sputters around 3000 rpm

Hey Guys

Thanks for the help as far as the clutch by the way! So, I got my clutch on and everything adjusted and torqued Wednesday night. The car would just start and die Wednesday night which was frustrating, so I just let it be.

Today I went and got new tires and fixed my linkage. (I had it bolted down wrong) which was causing a lot of other problems.

I took the car for a little test drive around the block. Good news is that the clutch is fine. I am able to shift into all the gears.

Bad news is, I messed something up while I was doing the clutch. The engine worked fine before I started, and now as soon as I hit around 3k rpms in ANY gear the car loses power and starts sputtering. If I let off the gas, sometimes the car just dies.

It accelerates pretty good up to 3k rpms and then it feels like the engine just stops working. Seems like either a fuel or a compression issue. What is the first thing I should check?

The car is driveable, but driving a Porsche that won't go over 3000 rpms kind of sucks. Any help is greatly appreciated.

Matt
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Old 11-06-2009, 04:40 PM
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RockStar951
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Check your battery negative ground on the bell housing. Ensure it is clean, connected and in good shape.
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Old 11-06-2009, 04:44 PM
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jacketfan89
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Good call! I just remembered I didn't tighten that thing all the way down because I couldn't find a 10mm wrench! I know it's screwed in a little, but the bolts not tight... Could this really be causing my problem???
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Old 11-06-2009, 04:55 PM
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RockStar951
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I was experiencing this problem for months. Check my past posts on this. I have just replaced my positive and negative battery cables and the car seems to be running a night and day difference. I am awaiting a replacement hood latch to do a road test and confirm it is really fixed.

Clean up the battery cable terminal and the smaller ground there and tighten it down. I'm curious to see if this resolves your issue.
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Old 11-06-2009, 05:05 PM
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Me too! I can definitely remember NOT tightenting that bolt down with a wrench now as it was a pita to get to and I just figured that if it was making conact with metal, it would at least be okay to test her out...just wierd that a bad grounding issue could cause a no start and lack of power like that. Thanks!!
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Old 11-06-2009, 05:43 PM
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Has it gotten consistantly worse? Check your fuel filter, mine did something similar but it got consistanly worse until the point I couldn't drive it. Changed the fuel filter and ran great!
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Old 11-06-2009, 05:48 PM
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Well I only drove the car 3 times before my clutch disk decided to bust apart...(test drive, PPI, and drive home...) however when I bought it there were no problems whatsoever with the engine starting or running rough...then I changed the slave andaster cylinder and then realized my clutch disk was bad so I replaced the clutch...now after I've put everything together this is happening...

I'm going to tighten up that ground connection when I get home...hopefully that fixes it!
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Old 11-07-2009, 03:26 AM
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I would like to know too. Had my mechanic change out my clutch this week and just got the car back today and very similar issue in regards to hesitation in 3rd and 4th gear around 3K range.

He looked at it again and adjusted something in regards to the crankshaft sensor or something like that. It ran better but still has a little problem. I guess I'll have to look into the grounding on the bell housing.
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Old 11-07-2009, 04:19 AM
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these cars are extremely sensitive to proper ground...having your negative cable bouncing around on the bell housing can't be good.

They are especially prone to heat, which if the cable's are corroded will induce higher resitance. My voltage on a cold engine start is up around 13v...once my car warms up it slowly drops down to just above the 12v mark.

I've got a set of Robby's +/- cables...already installed the supplemental ground but replacing at least the negative cable is on my list of to-do's when I have time to get the intake off again.
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Old 11-07-2009, 09:32 AM
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make sure the ref sensors are properly adjusted and not too far from the crank or touching.
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Old 11-07-2009, 01:36 PM
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Well....that wasn't the problem.

I went home last night and I was going to pull the car into the garage and tighten up the grounding bolt. For some reason I could not get the car to even stay running. It would start, idle up to about 1k, and drop down to 0.

I got a flash light and for some magical reason the light under the hood worked. I tightened down all the grounding wires...I tried to tighten up the battery connections as the positive connection is a little loose, but every time I put the wrench on the bolt I got a lot of sparks from the battery...is this normal? I've never had a battery spark before from tightening the terminal connections...

Anyways, I was going to ask if a dying battery COULD even cause any of the problems I'm having.

As you know yesterday afternoon around 1 I drove the car around for about an hour with it cutting off just to see if maybe after it warmed up it would do better..well I parked the car in the driveway and let it sit while I went to work...

I got home about 10:15 and like I said when I tried to start it, I couldn't keep it running. It was doing something a little different when I was starting it though.

Earlier in the day I would turn the key, it would turn over, then it would make a little whining sound like the battery was going dead for a second or two and then it'd crank and idle...and if I gave it gas it'd stay running...

Last night it was different...at first it did pretty much the same thing but it made the dying battery sound for longer before it'd start....

I rolled thecar to the street so I wouldn't wake anyone uptrying to crank it...

The more I tried to crank it, the longer and longer it would make that raaaaw raaaaw raaaaw dying battery sound when I turned the key. It got to the point where the car almost wouldn't start...I got lucky on one of my 30 times trying to start the car and I was able to start it in reverse and hold the gas enough to BARELY keep it running enough to get it back up the driveway.

It sounds like my battery is dying to me. Towards the end when I was trying to start it he headlights and inside lights seemed really d and the warning buzzer for the open door sounded weak.

I'm going to take my battery up to autozone and let them test it but I wanted to make sure that a dying battery could even cause my no power at 3k rpm problem.

P.s how do I get the battery out with it sparking like that? Lol
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Old 11-07-2009, 04:27 PM
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your battery should definitely not spark like that when putting a wrench on the + terminal. Still sounds like you've got a weird ground issue somewhere.

Do you have voltmeter? Have you tested the voltage on the battery when the car is off, at idle, and at idle with heavy load?
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Old 11-08-2009, 07:53 AM
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sounds like a fuel or vacuum issue... mine has a fuel leak somewhere some days it drips others it doesnt when it doesnt car works fine when it does leak car dies trying to start it gotta use starting fluid...

the over 3K RPM issue could be a Vacuum leak or a Crank Position sensor or even a Throttle possition sensor... I believe the DME only reads the AFM and TPS after 3K... CPS is always monitored as is the RPMs...

rule of thumb always remove the Negative battery terminal prior to the Positive terminal...

Just read your other post... about oil burning what happened with that..? could be part of your 3K+ no power issue if oil is leaking onto the clutch disc its going to ruin your new clutch job and for sure cause slipping..
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Old 11-12-2009, 07:32 PM
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Ok,

so I got tired of messing around with damned thing and decided to try to drive it to t Porsche mechanic 25 miles away (the whole ride is highway and the car does relatively well when the gas is applied...)

bad idea.

First off, there's a freaking tropical depression moving through Tuesday morning, but me being the eager beaver, I decided to still go with
my dad following.

The car cut off at a redlight..no big deal...turned right back on except NOW the headlights and windshield wipers weren't working...in the rain.

Whoever designed that windshield did a great job as with a little speed the water just beaded up and went off to the sides. So here I am driving down the highway and all of a sudden I see the Atlanta traffic. Damn I think it's going to cut off. Nope once the car was warmed up it idled fine in the traffic.

Then I noticed it. The temp guage wad going up....and up and up. So I pull over in this ghetto gas station and pop the hood. My heater control valve is leaking coolant. Great. Also, being the somewhat auto ignorant person I am, I went ahead and opened the coolant reservoir cap.

Another bad idea.

The top flew off and fluid bubbled out like a volcano, burning my hands as I watched helplessly..lol. Now what? Here I am stranded in the ghetto with an undriveable Porsche 20 miles away from my mechanic.

Dun dun dun dun! AAA

So the tow truck shows up to inform me that I only get 5 free miles and the other 15 would be $5/ mile...so $75 later my car was on a truck to Marietta.

Well I talked to my mechanic today. He cleaned the grounds fixed my heater Valve (luckily it was just the hose) and a few other small things. He said he still wasn't sure of the running problem. He told me that he's leaning towards the speed and reference sensors as those are really the only thing I changed during the clutch.

I haven't heard that these could even cause my problem, but hey I have no clue what symptoms dying (not dead yet) sensors show.

He said he will call me tomorrow before 1 and let me know the cause. Wish me luck!

Matt
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Old 07-02-2010, 01:52 PM
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What was the final solution to your running problem?
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