Runs/Drives, But no power, 5 mph max
 

I have a 2000 Boxster. It currently runs and drives, but will only crawl around, 5 mph max. Won't rev over 1500 rpm or so.

6 months ago, the alarm under the seat got flooded. I have had battery drain issues ever since, so could be related. I disconnect the battery sometimes, I found disconnecting it every month or so would prevent battery drain issues. I cleaned the alarm module with alcohol after it got flooded, seemed fine, but something is off still.

No power issue might not be related to the alarm issue.

I am thinking maybe throttle body? I did a quick search for this issue, but I didn't find anything similar.

Any input is appreciated. Thanks.

You need to read the codes, including the Porsche-specific ones and report which ones are triggered.

Who are you? An intro would be nice. Maybe a pic.

Sounds like limp mode

Yeah, I googled around, I'm thinking definitely limp mode. I didn't even know that was a thing.

It had a P 1502 code I believe, throttle body spring or something like that, so I put a good used throttle body in it from DC Auto. No change, so I googled more and found out about limp mode.

How do I get it out of limp mode? I'll start looking for answers now as well.

This person was having the same fault code. You can read through the whole thread, but this was the ending.

https://www.renntech.org/topic/40618-fault-code-p1502/?tab=comments#comment-220763

alarm under the seat got flooded? you mean the ECU? that is under the seat, and if it gets wet, you would have all kinds of issues. if it is actually an alarm, and it got wet, again, you would definitely have issues.

Yeah, the alarm module under the seat got flooded, I took it all apart, soaked/scrubbed it in first aid alcohol and it was fine except for intermittent battery drain issue, so really not fine, but the car ran normally.

I was disconnecting the battery at night because of this annoying issue (trying to save $1,000 to have the alarm module gone through by ECU Doctors) and then the car starting do the limp mode thing one day.

I put in a good used throttle body, new spark plugs, new spark plug tube seals, good used coil packs (I try to be thrifty with this car, it makes it more fun), still the same issue.

I am now thinking it's the gas pedal potentiometer, but I should probably send the alarm unit to the ECU Doctors. I am also having a shop look into the issue. The alarm module under the seat on the floor in a convertible is a massive design flaw in my opinion, they should have put it somewhere else or at least a drain the floor, I added a drain.

This forum gave me a great tip on getting the spark plug tubes out, that was great, transom plug with some sand paper, grabbed the plug with pliers on the stuck ones.


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I completely agree

Have you rechecked for codes? Going off memory is not very accurate.

Throttle Issue - Pelican Parts Forums

I found this post, basically the same issue. The local European car specialist couldn't figure it out, so I am back on the case.

It could be the "throttle accelerator sensor" or the pedal.

I am starting to think it might be the mass airflow sensor

I unplugged the mass airflow sensor, it ran normally. I think I put the wrong one in 6 months ago.

I need to get a 996.606.124.00, right now it has 986.606.125.01

I might also be this

https://www.ebay.com/itm/Porsche-986-Boxster-996-911-00-04-Accelerator-Gas-Pedal-Cruise-Control-Man/152622830858?hash=item238907950a:g:EAkAAMXQVT9S7dn W

below is a quote:


If you are replacing your sensor, it is extremely important that you get the proper one for your car. There are two basic types, one for the cars that use a traditional throttle cable (up to 1999), and one for cars with an E-gas electronic throttle (2000 and later). In addition, the later-style E-gas sensor has been updated at least twice as of this moment. Porsche updated the sensors in the Boxster in mid-2000 and also released a new version of the DME software that is a required update if you are going to use this new and improved sensor (see Porsche Tech Bulletin Boxster 1a/00 2445). Here is a chart that shows the differences between all of the sensors:

If you own a 2000 Boxster or 2000 Boxster S, then you need to make sure that you have the proper sensor installed. Much confusion lies in the fact that most people don't know if their car has been updated by Porsche or not. If the old sensor that you removed is 996.606.124.00, then you need to replace it with the same part number (or have Porsche update your DME software to accommodate the newer style sensor: see Technical Service Bulletin 1/00 2445 Air Flow Sensor -- dated 4-18-00). If the old sensor you're removing ends in 125.00 or 125.01, then replace it with 986.606.125.01 (the latest version available).

Thanks for posting the solution.

Just out of curiosity, did it run poorly immediately after you installed the wrong MAF 6 months ago, or did it creep up later?

It ran much better actually. I think it was the consistent battery disconnecting that triggered something. I still don't have the new one, it's taking forever, shipping issue.

I still won't know until I try the new one. If that doesn't do it, it's going to a Porsche specialist.

By the way, I re-cleaned my alarm module under the seat with 97% first aid alcohol, soaked it for 20 minutes this time and scrubbed it with a toothbrush, battery drain issue went away. I took the board out of the case when I did all that, should have taken a picture.

I think the IMS bearing went, the engine is done, what do you all think? I told a Porsche Specialist the symptoms, he said drain the oil, check it.

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I've neither read nor seen anything in your thread that would make me think the IMS has failed.

How and why did you come to such a conclusion?

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Dave_R
On 5-10-2019 you stated that you unplugged the MAF and the car ran fine.
What I see from your posts is that you have.
1. a problem with the module under the seat. Which you believe is connected to your battery drain problem.
Which you may or may not have fixed.!!!!!!
You need to do some proper testing of the electrical system to prove fixed or not fixed.

2. As to your car possibly being in limp mode. (or what ever the problem may be) you need to do a proper step by step diagnosis. Which starts with the simplest things first. Like what codes if any are you getting.
The more things you replace (like the throttle body). or "fix" without knowing with reasonable certainty that they are the problem. The greater chance you have of compounding the problem or creating issues that didn't exist in the first place.

If you do not know how to do a proper diagnosis of the problem I would say hire someone or a shop that does.

you could spend a ton of money replacing parts and chasing ideas that you think are the problem. Potentially way more the a reputable shop would cost you.

If when you unplugged the MAF the car ran fine. (as you stated on 5-10-2019)
I doubt very much that you have an engine that is toast. It could be a very simple issue.

All of the metal in the oil filter, the oil had tons of metal in it. I guess the cam timing is off when it the IMS goes, causing limp mode. Makes sense to me, I think it's dead. The odd thing is the normal revving when I unplugged the mass airflow sensor.

It did make a funky noise once while in limp mode.

All of the metal in the oil is why I think it's the IMS. It was worse in person. There were some serious chunks.

With sadness, I'll have to agree with Dave on this. Maybe not necessarily the IMS, but I wouldn't rule it out. All that glitter and metal chunks in the oil don't bode well for the health of the motor.

Yeah..... that's kinda what I was getting at too. I just see so much blamed on the IMS...
From everything I've read (and im glad that's the only experience i have with failed IMS) the first indicator is invariably the NOISE it makes.

None of the typical IMS failure symptoms were described in this thread.

But yeah, the pretty glitter in the pan is no bueno.

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