New owner with first problem.

Well I expected it to happen....just not so quickly.

It will be obvious from my post...this is my first ferrari.

Last month I purchased a 87 328 GTS. Inspected, well maintained (documented), well kept, reputable owner and just all around beautiful car.

I put a few hundred miles on it that week and was just thrilled overall. Left town for a few weeks and returned last week and of course, had to go out for an evening drive. Good cold start idle, proper warm up period and a spirited jaunt in the desert. Twenty miles or so into the drive the engine begins to miss just slightly....then more aggressively. Loss of at least 50% or so power for a few seconds then back to normal. This will repeat and the infamous "slow down" light will begin to flicker and become more prominent. Wash, rinse, repeat....Fortunately, I was close to home and gently eased it home with the fire extinguisher at the ready. I understand the meaning of the slow down light and the potential consequences of not heeding it.

The next morning, I went out and the car started immediatly and had a good cold start idle and purred as it should. Once the temp begins to register...the miss begins again with some slight backfiring...very minor. Upon shut down I detect a slight (nose at the exhaust tip) smell of raw gasoline. Obviously something is not firing. I haven't washed the car and the environmental conditions were the same.

My plan is to begin with checking the plugs and new extenders and work back from there. I'm going to get a timing light as well. My mechanical skills are moderate at best and mostly with old BMWs and 2-cycle motors.

I've looked at as many threads related to this issue as I can, but am just looking for some reassurance. Is this the best starting point or is there something else I'm missing? My concern is the dramatic loss of power might mean more than just a bad plug extender...possibly the distributor, but would that be an intermittent problem. As you can imagine....It would break my heart to do something stupid and ruin such a beautiful car. I will return home again next week and hopefully begin to solve this problem.

Any information or links to some more threads would be greatly appreciated.

Thank you in advance.

 

a large drop in power and the slow down light usually means ignition loss on a bank. The timing light and meter will help a lot.

I'd do this:

• run car until problem starts happening

quick checks

• wiggle the plugs going into the modules on top of the coils to see if it's a bad connection there.
• stick timing light on each coil wire to see if the coil is firing. If you find one of the coils isn't firing, swap the connectors between the two modules on top of the coils. If the problem moves to the other bank, it's the module (marelli BKL 3BA).

both coils firing ok

• use timing light on individual plug wires. If they are all ok, it's plugs and extenders.
• if lost spark on some/all wires, remove distributor cap and check for problems with rotor, carbon tracking, deteriorated posts, presence of oil, or worn down carbon button in the center. Then use an ohmeter to check individual wires. Sometimes you can just unscrew the wires, chop a bit off the end, and remount them.

one coil not firing

• using a voltmeter set to AC, measure the voltages on pins in the diagnostic socket while idling:
  • >0.2V AC between pins 1&2 (car not running, ~700 ohms between these pins)
  • ~3V AC between pin 1 and gnd
  • ~3V AC between pin 2 and gnd
  if any of the above no good, check the two wire harness plug connectors that are mounted to the bottom of the oil cooler air duct. The round black plug is for the flywheel sensors, and the large white plug has the ecu->coil wires in it.
• remove the ignition ecu plate (left side of trunk under carpet) and check the ecu connector, then referring to the diagram below, disconnect the plugs and wires on the coils and check connectivity from the ecu connector to the various coil connectors.

I think rifledriver has said the most common reason for bank loss in a 328 is the module on top of the coil. Since your problem seems heat related, take a close look at the pins inside the various connectors for corrosion or loose fit.

Loss of a bank doesn't make the car idle badly, it just drops the power a lot. If the car idles badly, it's more likely that something common to both banks is the problem. On a 328, that would be the flywheel TDC sensor, bad wiring harness plug connections, the ecu ground, the ecu connector, the 12V supply to the coils/ecu, or worst case - the ecu itself.
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Phil,

Thanks for the info...

I appreciate a more methodical plan based on symptoms than me starting at the plugs and working backwards.

Once I get into this next week, I'll be sure to post my trials/errors and results.

Thanks again.

 

Only a quick though to add to Phil's excellent list: the 328 FI system uses a Bosch "protection relay" (on the FI ECU plate) that is notorious for causing odd idle issues. It's fused (10A); I have a spare I can lend you if it would help in diagnosis?

Best,

Carl

 

Carl,

Thank you for the offer...

As far as I can tell, the idle is fine until the vehicle heats up. Starts quickly, good cold start idle and sounds great. It's when the engine is up to temp and doesn't matter whether at idle or under load/high rpm that the problems begin.

Once I begin my process of elimination I'll know more.

Thanks again for your offer.

 

This would be my bet, the relays are a weak point in a very strong car. Vibration works mine loose so I ahve zip tied it and duct taped it in position... its a gradual loss of power in the form of a miss... belwo 3500 RPM when it happens... literally a 2 second fix.

 

I hope that's all it is. I just had to leave in such a hurry that I wasn't able to do any good troubleshooting....and you know how the mind can jump to worst case scenarios.

 

yo spirot, bung what car you have into your profile

that relay is kinda interesting. As carl said, it has it's own fuse that is wired directly to the battery. The diagrams in the paperwork shows that internally it has a zener diode. A zener is normally used either as a crude voltage regulator or just as a voltage spike protection device.

The protection relay closes when the fuel pump is running, so a quick test is to put the key in the run position and unplug the blue plug from the fuel distributor. That'll close the fuel pump relay and the protection relay should click closed too.

So what's the relay doing? It's wired a bit differently between various models, but in all cases the zener protected voltage is getting fed into the injection ecu...probably it's the ecu's main power supply, so when the fuse blows...or in spirot's case the relay falls out...the injection ecu shuts down. That would in turn stop the frequency valve, which would peg the fuel mixture to the rich or lean extreme that the FV is capable of (not sure which) and that would definitely effect the engine operation, most noticably at low rpms. Pretty much the same thing as unplugging the frequency valve.

note that on cars without a frequency valve, the base fuel mixture is set and only the warm-up regulator can mess with it. The cars that have a frequency valve also have a base fuel mixture, but it's set when the FV is running at a fixed 50-60% duty cycle. If the FV shuts off, the base mixture is wrong.

the zener clamped voltage goes elsewhere besides the injection ecu. It interacts with other relays on the injection ecu plate to directly or indirectly power the cold start injector, the thermo-time switch heater, the O2 sensor heater and/or the exhaust air injection electrovalve/control valve - all depends in the model and year.

the fun part is how all that stuff interacts. All I can say with certainty is that if the relay or fuse is bad, an 1989 328 idle will drop and it will run roughly - at least when cold. It's easy to tell, as the frequency valve won't be buzzing. If the problem is intermittent due to dirty relay contacts, poor relay socket connection, or something with the fuse, then the symptoms could look like an ignition problem if the mixture is too far off to burn well.

if the timing light says that spark is good to all cylinders and the extenders look ok, and the plugs aren't obviously burned/fouled/sooted up, then check the protection relay, and get carl to send you his write-up on testing the injection ecu and the fuel pressure. Get his ignition ecu write-up too...it has more tests and details than I posted above.

 

(laughing) I think Phil has me pegged for a lot smarter than I am! (smile)

Seriously, if anyone would like a copy of what I've put together, drop me an email with your address to [email protected] & I'll get you out a CD-ROM of all my "how-to"s within a few days. I can email the smaller ones, but some files (ones w/lots of pictures) are too large.

Here's a picture of the potential perpetrator, Porsche part #92861512400 [Bosch #897130], retailed for about $157 about 2 years ago:

Best,

Carl
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I just getting used to having a Ferrari in the garage...when I couldn't get it restarted in the driveway after a great Hwy 74 drive. I had lost all power and it was a bear to start...raw gas smell clearly....I floored it gently figuring it was the Ferrari hot start start problem. I have left it sitting for a week seeking info on a good independent shop in SoCal near Palm Desert/LaQuinta and a reasonable transport flatbed. This morning I called Norwood Performance in Dallas about another shipping detail, and mentioned my problem. Mike had me go look for the # on top of the coil so I could order one. when I put my glasses on to unscrew the metal cover...I noticed one coil had a orange wire coming out the bottom...and the other had a shiny spot!!!. Reach down.....feel around ....find wire....replug it in. Instant start. Since I own a 62 MGA and know about LUCAS (Prince of Darkness) Electrics, I now know to keep my MG knowledge available. This spring I wondered why my AC on the Miata was inoperative.....winter rodent chewing..... Lesson learned again. When in doubt, track the obvious and less
obvious wiring routes and connections....with your glasses on. I just ordered a spare coil...with the MG and the old 912 whenever I had a spare, it was insurance that I would never need it. We'll see. Thank you to all who have written here, your information got me started and eventually helped get #73231 fired up again. Thanks Paul

 

I had a very similar problem with a 308. It would run fine then sputter. One bank would not fire and then it would work fine. It turned out one of the rotors one the distributer cap was cracked. It would presumably vibrate loose and misfire. It eventually completey fell apart and that's when I discovered it. Once replaced ran fine.

 

Email sent

 

Happily, they got cheaper:

http://www.ricambiamerica.com/product_info.php?products_id=229521

(and a proper Porsche dude might have them for less. Wayne@Pelican Parts perhaps?? )

 

Heading home tomorrow to start troubleshooting. Ya'lls posts are giving me hope that this is something more simple than the conclusions I've jumped to....

Keeping fingers crossed..

 

Yeah, and you're a professional jumper, too!

 

Oh, you have no idea

I'm trying not to bring my professional life into my recreational life....I just don't want to be standing next to my beautiful 328 thinking to myself, "Oh, look what you've gotten yourself into now"

Wait....scratch that, I've already did that the next morning after the 328 came home.

Oh well, out of the frying pan and into the fire......

 

I see you didn't "just" wash the car, but have you washed the car lately?
Water can get into a lot of key components on a 328 and the moisture will move around during heating/cooling cycles.
The coil modules, the ECU (thru the antenna) and spark plug circuits can be hampered by water coming thru the grates.
If you wash it, you should put plastic over the engine and it would be a good idea to put a towel under the antenna because the FI ECU is right under the antenna.
When you get the car warm all of the moisture does not evaporate--especially around the plug extenders and the coils.

Mark

 

Thanks Mark,

I've only had the car since July and been traveling most of the time...so, no, I've not washed it. But when I get this problem sorted out...she'll need a bath, so the info on protecting the electronics is appreciated.

 

Firstly, thank you all for the information....

Using the timing light, I've been able to narrow down the problem to the rear bank (1-4) was intermittently firing. Swapped connectors and problem moved to the front bank (5-8). It's an intermittent missing of the bank (more not firing than firing)...and not temperature dependent.

Using the multimeter....I ran through your "one coil not firing" checklist and all seems well. Checked the connectors at the oil cooler and they seem fine as well.

Ran through the ECU and everything looks good as far as I can tell....

Also of note, the heat dissipator (sp?) (metal fins) on the rear bank (1-4) module is much warmer than the front bank.

So....It's looking like the module on the rear bank is going bad if I'm sussing this out correctly.

Any thoughts???

 

Carl,

Also, checked out the relay....fuse good and it was already zip-tied in place. Connection looked good as well.

Found three black marbles underneath the plate as well....hmmmmm.

 

I have had ignition problems in two of my Ferraris in the past. One, on my 1986 TR, was related to a relay and when replaced the car has never missed a beat since. The other, on my 83 BBi Boxer was related to the two alternators on the car that were worthless. When rebuilt, again the car hasnt missed a beat. It cost me small fortune to find out what was wrong, and in each case, only after lots of effort were the culprits found. I do not know what is causing your problems, but i thought i would mention my experiences.

 

Well....after running through the diagnostics, I decided to pull off the offending coil and module. Gave all the contacts a good clean and cleaned the contact between the module and the coil...trying to leave what I think is some dielectric grease (?) between the two.

Put it all back together and we now have a happy running 328 in the garage with a nice pulse on the timing light...

Next, the cautious drive around the neighborhood.

Sounded great and ran like a top for about 10 minutes after up to temp....then back to the intermittent loss of the bank and the slow down light. Next, a new module.

 

it's heat sink compound....a goo that helps conduct the heat between two surfaces. In this case, the coil frame is being used to slurp heat away from the ignition module.

you can get heat sink compound at radio shack or places that sell computer components. It's used all the time between the CPU and the cooling fan in your computer.

since swapping just the plugs moved the problem to the other bank, only the module could be the problem. Removing and cleaning the pins in the module, and applying some new heat sink compound is all you can do. If it still has trouble, the module is bad.

Module failure is more likely to when it gets hot.

when buying another module, ask them if it comes with the heat sink compound. I picked up one from a local parts place that was actually for a bmw, and it came with goo. However, it wasn't a suitable replacement, so I had to return it...it ran the engine, but the ecu control voltages got shifted 2x higher than they should be.

the replacement module I got from GT car parts didn't come with heat sink compound, but I had some Arctic Silver compund laying around from a computer system build that I used.

for people who like pics, attached is a what the inside of a module looks like...with most of the gel-like material removed. Opening a module will destroy it as you have to tear off some of those bars that are attaching the module pins to the circuit board pads.

standard disclaimer - these modules are used on the 328, not the 308 gtsi/qv.
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Thanks for the intel....heat sink compound, I like that.

How does the module communicate with the coil...via the compound?

Back in the day, I worked with specialty industrial lubricants and we produced some interesting products...mostly for arc squelching...or ensuring conductivity on things like airbag connections. Is this a similar conductive compound?

Regardless, I'm going to try to locate a new module, but if anyone has intel on the specificty of the compound or where to locate a module I'd sure appreciate it. I've found some names/numbers from old threads, but anything current would help.

Might have to call on my old boss and see what he has to say about the goo.

Wolf - thank you very much for the information. I wouldn't have made it this far without it. You've given me a weekend of narrowing things down rather than taking shots in the dark.

 

Those are my marbles, I lost them a long time ago...



(Sorry, I couldn't resist. Good luck with the new module.)