I have done none of these maintenance items and I am at 93K miles. I've only done suspension and drive train. I am feeling some of the same sluggishness you mention and thought it was my clutch for the longest time, but after a recent 800 miler it's fine.
I do have a crack in my exhaust that needs to be welded and I am suspicious of the sensor and or the cat, but as yet no codes thrown. If you have done all these items and are still chasing it, is the MAF truly the last?
Zaraska doesn't have a MAF you could swap?
It wasn't so bad as I do all the work myself. I'd say all together it was about $1500 since I got a used DME and a lot of good deals for brand new parts to eBay.de
I talked to Will and asked if he has one I could try out and he said no. I know he has a 3.8 M5. I might hit him up again and see what he says. I don't see it being anything else, unless the injectors are bad. Fuel pressure and everything checks out.
Hi Mark, I agree with you on the MAF being a possible cause, but I've noticed the same sluggishness on occasion in my 3.8L. The only time I've noticed this is when I've driven the car shorter distances repeatedly (like 30 minute or less "normal" drives). Each time the car "cleared" and came alive again after a good hour long drive with some true driving the way the car is made.
Its like the car gets grumpy if you don't drive it like its intended. So, when was the last time you went for a good 1hr plus drive with the car? Maybe its just begging for a long drive.
Hi Mark, I agree with you on the MAF being a possible cause, but I've noticed the same sluggishness on occasion in my 3.8L. The only time I've noticed this is when I've driven the car shorter distances repeatedly (like 30 minute or less "normal" drives). Each time the car "cleared" and came alive again after a good hour long drive with some true driving the way the car is made.
Its like the car gets grumpy if you don't drive it like its intended. So, when was the last time you went for a good 1hr plus drive with the car? Maybe its just begging for a long drive.
-Russ
My drive to work is 50 miles each way, which is at least 1hr, so the short drive is not the case. The drive home is at least 1.5 hrs due to traffic. I have done a 250 mile drive with no difference in response.
You may have already double checked your work but just in case...
When I changed my vacuum hoses, I also cleaned the oil separator and vacuum reservoir along with the vacuum check valve.
It's important that the flap not only opens but remains open and does not leak any vacuum as well
Is your flap easy to operate through it's full range?
Something might have have become disconnected upon reinstall or got loose because it wasn't sitting properly to start with.
Has the air pump been disconnected? Check there too for vacuum leaks.
Sometimes it's a good idea to assume that what you think is working isn't and start over again... I know what a drag right?
You may have already double checked your work but just in case...
When I changed my vacuum hoses, I also cleaned the oil separator and vacuum reservoir along with the vacuum check valve.
It's important that the flap not only opens but remains open and does not leak any vacuum as well
Is your flap easy to operate through it's full range?
Something might have have become disconnected upon reinstall or got loose because it wasn't sitting properly to start with. Has the air pump been disconnected? Check there too for vacuum leaks.
Sometimes it's a good idea to assume that what you think is working isn't and start over again... I know what a drag right?
This is an interesting point Manuel. Some of us have disconnected the air pump. Do you think that leaving the transparent tube to the air pump disconnected might cause a poor engine performance?
__________________
Ramon
'89 E34 M5 3,6 Macao Blau
'99 E38 740i Biarritz Blue
'03 Seat Alhambra 1.9TDI 115hp. Black
'82 Renault 9TSE
I have done none of these maintenance items and I am at 93K miles. I've only done suspension and drive train. I am feeling some of the same sluggishness you mention and thought it was my clutch for the longest time, but after a recent 800 miler it's fine.
I do have a crack in my exhaust that needs to be welded and I am suspicious of the sensor and or the cat, but as yet no codes thrown. If you have done all these items and are still chasing it, is the MAF truly the last?
Zaraska doesn't have a MAF you could swap?
Lambda? You mention that you have an exhaust leak (most often at the joint where the manifold connects to the rest of the exhaust system), this extra air will fool the lambda resulting in an incorrect air/fuel mixture. May be worth checking...
You may have already double checked your work but just in case...
I already tripple checked along with a propane going over and there are no vacuum leaks. The resonance flap works as intended. If I rev the engine I can see it move and I also did the grease trick.
I have a TPS on order and will see if that makes any difference. If not then the MAF is next. Grrrrrrrr. Thankfully my E28 M5 runs like a top.
For real-time diagnostics on how the engine is running, I installed a Wide Band O2 sensor and gauge to my E30 M3 and boy has is put me on the right track many a time.
It's from Techedge LA1 Wideband Display for WBo2 (Tech Edge) and was supplied to me by the same guys who provided my carbon intake manifold and Alpha-N fuelling ECU. Paul Shepheard then used it to set up my car on the rolling road.
Installed as a stand alone unit in my case, I use it as a tuning tool to keep an eye on the mixture throughout the rev range and it's so sensitive that it will highlight faults from Vacuum leaks, TPS, MAF, faulty coil/spark plugs, fuel pressure, exhaust leaks etc.
If you accept 14.7:1 Air to Fuel is the standard burn reading, going richer as you accelerate to wide open throttle (I run 12.6:1 for example) and slightly leaner on cruise, any wide variance or fluctuations on that will indicate a problem somewhere and it's then a logical process of elimination to find the cause.
I guess you first need to know what a good map would produce for a standard car but you soon get to understand what feels right and looks like for the revs and throttle position.
Blocked CAT's was mentioned earlier in this thread and my brother's Lotus V8 suffered from that - down on power, excessive consumption; so shouldn't be discounted from your investigation.
Cheers,
Dave.
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Alright, I'll suggest a couple things more then I will shut up (I don't really know what I'm talking about anyway ).
I would check to make sure that the DME is receiving the signal from the coolant temp sensor(s) correctly. I would also try disconnecting the air pump (unplug the relay, additionally review the wiring diagram of all sensors going to the DME). How long has it been since you ran some injector cleaner? Have you been trying different gas stations?
Lastly, I would make sure that the exhaust manifold bolts are all tight.
To answer an earlier question from Robinson about the air pump vacuum pipe, I would simply make sure it's plugged and that it's not causing any vacuum leaks as a result.
Well, I pulled off the cats today and they are fine, no melted core and not plugged. I don't hear an exhaust leak and used new gaskets to put it back together. I also installed a set of new plugs and the battery cable was off for the 3hrs it took me to do it.
Got back in did a 100km drive and no change. I also disconnected the air pump as per earlier suggestions. No difference.
Well once the TPS arrives we'll see, if not then a new MAF will be ordered making my wallet significantly lighter.
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