bott63

Just curious if anyone here has tried LM1 or LMA3 Performance Tuning Systems by InnovateMotorSports.com - Worth the $$?? I saw this tool on the diagnostic/tuning section of Pelican... I was considering trying one out on my '85 Carrera, and was curious if anyone had luck using this tool on a DME or Motronic type system.....

Pat

J. Brinkley

Works like a champ, as far as setting idle mix goes, way better than those gastesters. I think it's worth it. good info on this forum http://www.innovatemotorsports.com/forums/

bott63

Thanks for the review Jerry! I was curious if the tool might be able to diagnose problems within the DME and fuel system under driving conditions.... Would that be better accomplished with the LM3A unit? Any knowledge on that unit?

Thanks,

Pat

J. Brinkley

I doubt it. I would use it/ am using it to monitor, the controller itself won't tell you any problems with DME, only what AFR's are at any given time. You can log for a set period of time and see what your chip is doing throughout the range in real time. But all that is set. People like Steve W. use that to make chips. I'd call innovate or Steve for more info

bott63

Thanks Jerry....

I've been chasing after a problem for a while now... I have swapped I think just about every conceivable part to no avail. It looks like my next plan will be to check each wire for continuity at the harness. I had added my problem to another link where a fellow was having similar issues... "Venting 911 frustrations..."

J. Brinkley

If I had a motronic problem and couldn't swap with a known good one I'd send it off to loren or someone else that could guarantee it's condition. It's not all that expensive.

J. Brinkley

I just read all that, I'd clean the AFM- air flow meter, barn door, not MAF, hot wire or anything else. Clean it like they said. clean the ICV- idle control valve, test it like all the other FI tests in bentley.
here's a book called Bosch fuel injection and engine managemment by Chales O probst. You can learn everything about CIS and motronic in there. There also are generic bosch O2 sensors for $40 that you can solder the porsche conector to that work well.

bott63

That's just it... I'm banging my head against the wall on this one! The throttle body & airbox were swapped out from a perfect running car, and it still did its funny stuff.... I'm leaning more towards an electrical short somewhere, as all other suspect parts have been replaced. DME Relay, HTS, o2 sensor, temporarily swapped a DME unit from a different great running car.... All to no avail.....

Lorenfb

"I've been chasing after a problem for a while now." - bott63 -
"it still did its funny stuff." - bott63 -

Further define your problem in clearer terms, as many on Rennlist are capable of helping.
Most/all 3.2 fuel injection/ignition problems have been solved on Rennlist.

bott63

Loren, thanks for taking the time to respond! Very cool web site you have. Does your shop actually diagnose problems on the cars, or do you mainly work on the computers that people drop ship?

I've been chasing after a problem in my '85 Carrera (130k miles) for some time now... While my car doesn't actually stall or quit, or burp at 5k rpm, it will seem to bog out between 2800/3200 rpm. The drop in power occurs when driving mellow at maybe half throttle shifting at 3.5k Above and below that range, when the car does its bad behavior, the car runs strong. This problem is intermittent at best. Sometimes when hot, sometimes when cold... Sometimes not at all
I've gone through the usual.... Vacuum lines replaced, new plugs, wires, cap&rotor, fuel filter, DME relay, HTS, O2 sensor, and the problem still is around... After all of this nonsense, my independant mech. swapped a DME from an '86 that works perfectly, and still no fix. Also, all ground wires were checked. There was slight resistance on the battery cables, so we put in new ones, pos & neg, and cleaned up the frame where the ground wire connection is made (minor corrosion.) Also removed the quick disconnect from the battery & replaced with OEM, and a new battery. After that, the problem was about 80% gone. It is returning though, and getting worse. Compression check and leak down showed absolutely no problem. Also swapped the airbox and MAF from the other good running Carrera, with still no improvement.... Fuel pressure is excellent, injectors flow tested with no problems observed... The HTS replacement was an OEM single pin connector. I read a Pelican thread that there is a beefier upgraded HTS 2 pin connector that might actually be a 930 part. Anyone know about that? I guess it's possible that I got a defective replacement HTS.... Or perhaps this is just the weak link in my car.

I'm running a K&N air filter, and read the other post that sometimes the oil on the element can pollute the MAF & intake, but I did try swapping the MAF to no avail... Also, I'm running with bypass pipe, no cat., but did that switch over 50k miles ago with no problem until recently... Also, I'm running an Autothority chip, but did swap in the original chip, but still no change... I'm at a bit of a loss here. I'm thinking, and hoping, it's not a mechanical issue, such as bad valve guides, or bad valve, as the problem is intermittent. Car doesn't burn excessive oil - 1500k per qt. of Mobil 1 on a 130k motor. I would think that my computer is ok, as I swapped one from a perfect running Carrera, only to see the problem remain in my car. Perhaps it is indeed an electrical short somewhere between the harnesses?....
Pat

Lorenfb

First, your problem is very unlikely related to a mechanical engine problem.

Next, let's understand what's been done:

1. replaced the head temp sensor
You could just bypass it by jumping the white connector with a paper clip.
Keep one in the glove box for future failures.
2. all vacuum lines replaced/checked
3. new cap, rotor, & wires
4. checked fuel pressure
How about monitoring it under load when problem occurs?
5. replaced DME relay & ECM
6. replaced O2 sensor
Could have just disconnected it to isolate it. Will run fine with out it.
7. replaced AFM & filter
You did mean an AFM & NOT MAF which was only first used on the 993.

Things not mentioned:
1. ignition coil
Did you check the strength of the spark. S/B > 25mm at coil wire to engine ground.
2. Monitor DME voltage when problem occurs.
3. speed sensor voltage, ref sensor can be disconnected after engine starts to isolate it.
4. clean all electrical connections & solder ones that are just crimped, e.g. grounds
5. clean all connectors, e.g. AFM connections
6. monitor injector rail voltage while driving

Most likely cause; lean fuel enrichment. Although, you say that the AFM was replaced,
did the problem re-occur as before? Your problem is typical of a sticking/lagging AFM.
You do mention on Pelican that you sprayed something into the intake that solved
the problem for a short time, right? If so, this confirms the problem being related
to a fuel starvation/ lean problem, or affecting the AFM.

Try reading the Diagnostics page ( www.systemsc.com/diagnostic.htm ) for additional insights.

By-the-way, who's your mechanic in Brea, as I know/work with most SoCal Porsche shops?

bott63

Loren.... Thank you very much for the VERY informative response!

My Mechanic is Curtis Beener/Positive Performance in Fullerton. I would have to guess you know him, as he's been in the business for many years. He knows most of the wrenches around here, but I haven't spoken to him since I've jumped on this board... He also had his buddy Chris, one of the Head Porsche Mechanics down at Newport Imports look at it for about 6 weeks, almost a year ago.... I believe that Chris put in a new fuel pump, and cleanend the bejeezus out of everything... Connectors, harnesses, not sure about intake.... He did the shotgun approach, and really couldn't tell me if it was any one thing in particular. Ran great for about 10,000 miles, until I did a road trip to Reno last Sept. to see the Reno Air Races. Drove like a banshee (110+)all the way north, and the car ran flawlessly! Car sat for 2 days, and the minute we started driving back, it ran like ****... All the way home... And back to Curt... And the attempts to correct the now almost constant problem started again by doing the things listed in the above message... Maybe the AFM became polluted by the K&N filter after a long hard drive? If I could only remember when in the heck I cleaned the filter last, I might be able to tie this ugly puzzle together.... Where the AFM sensor plugs into the AFM, does the sensor actually come out pretty easily to clean by itself? Is that the one that comes out with 4 very small phillips head screws?

But this raises another question!... Didn't replace the AFM, but swapped a perfectly functioning one, from another donor car... Problem remained. Same result with the ECM.. Swap, but no fix. Didn't replace the Air filter, still run with the K&N... Could that be a part of the problem?

You have asked a couple of questions that I will need to ask Curt... Crimped lines, I don't know about... Any common locations in particular I should check? I know all the sensors have been checked for continuity and proper voltage, but for under load as well, I will need to confirm.... Coil checked out ok... As far as monitoring DME voltage when problem occurs, could that be done with the old original Porsche Factory Motronic piggyback diagnostic tool(another ridiculous $10,000 Porsche tool)? Curt has used this tool extensively on my car with no luck isolating the problem...

I can't say for sure that spraying intake cleaner on the AFM temporarily cleared the problem, as the problem is now intermittent..... I was going to try again spraying it in the intake with the motor running & see what happens... I will speak with Curt tomorrow, and DEFINITELY share your thoughts, as you have raised some ideas that we have not spoken about...

Thanks again Loren, and I will update you tomorrow....

Pat

Lorenfb

"Where the AFM sensor plugs into the AFM, does the sensor actually come out pretty easily to clean by itself? Is that the one that comes out with 4 very small phillips head screws?"

No screw removal is necessary. Just unplug the connector from the AFM.

"could that be done with the old original Porsche Factory Motronic piggyback diagnostic tool(another ridiculous $10,000 Porsche tool)? Curt has used this tool extensively on my car with no luck isolating the problem..."

There's no DME interface nor diagnostics provided on the 3.2 system. So don't know
what your mechanic was doing.

Another thing to check is the centrifugal rotor advance. Can be a problem if sticking.
This is just used to sync the DME advance with the placement of the cap wires &
not to provide the actual advance as on the older 911s.

A key point to remember:
The problem is intermittent, so ALL tests when the problem is NOT occuring are of
little value. Tests must be done at the instant the problem occurs.

PorschePhD

If I might poke my head in here for a moment. I am not seeing a couple of real issues that are common checked for. The first is the intake nuts. They are barrel nuts and very often are loose and almost never get checked. I have seen this to many times to mention.

Other missed issues. Bad injector. Either from the injector harness or the tip of the injector. I am seeing more and more failures to the harness as the way the factory routes the line causes issues. If you look at the injector harness it is routed form the back of the firewall and twisted in its holder. The twist causes the wire to break. Since the injectors are batched it can cause an improper signal and dump fuel. Hence the bogging you might have. The physical issue with the injector are the tips fall off and will cause an irregular spray pattern. Something to check for.

Oh, FWIW the LM1 we use to steady state tune on our dyno and the LMA-3 is also good.

Lorenfb

"The first is the intake nuts."

This type of problem results in a lean idle misfire & not a problem at 3500 RPMs.
Also, this type of problem is NOT intermittent.

"Bad injector."
"The physical issue with the injector are the tips fall off and will cause an irregular spray pattern."

These types of problems are rare and never an intermittent.

"I am seeing more and more failures to the harness as the way the factory routes the line causes issues"

The Porsche 3.2 does not have a record of harness problems as does the 993.
Also, a failure of the harness will cause a more noticeable effect, e.g. shut-down, than bogging.

Again, since the problem is intermittent, focus on system elements which could BE intermittent.