[derfa7]

Hi Everyone:

I am new to the Bulletin Board, but have had lots of Alfas in the past--all with either Spica injection or Webers.

Recently, I got a black 1985 Alfa Graduate that my sister bought new. It has been babied and regularly serviced and it in top condition.

Last month, I drove it to the Italian Car Day in Atlanta--a 200 mile trip. The car ran beautifully even through some rain.

Once home, the car sat outside overnight and by the next morning all hell had broken loose. I have listed the details of the Great Exploding Spider below. Any diagnostic or repair ideas that would help me get the car back on the road would be appreciated. So here goes:

THE CAR: 1985 Alfa Graduate, Black, with 119,000 miles, well maintained.
Jetronic fuel injection with a flap-operated air flow meter.
The distributor has no primary wire or vacuum advance. The bell housing has two sensors on the passenger side.

(What is this system called: L-Jet? Motronic? I bought the Probst book but don't know which section to read.)

SYMPTONS: Car starts well and idles well, but just above idle the car runs rough and misses. At about 1/2 throttle the engine runs and quits, comes close to dying--but never quite does. Above 1/2 throttle on up to wide open the engine still runs poorly then dies, then runs, etc. Every time the engine "catches" there is a hug backfire--a long flame and plume of black smoke out of the tail pipe. It is all very violent and frequent and could provide the background effects for a war movie.

The tachometer seems to read OK at idle but clearly reads low above idle and takes a huge and sudden jump up just before every exploding backfire.

REPAIR PLAN:
Plan?
First I plan to clean all the grounds. So far I have found the battery ground, the ground strap on the bell housing, and the black wire cluster on the right valve cover. Others???

After the grounds, I have no ideas except to "shotgun" parts replacements.

Assuming there are relevant fuses, where are they?

Is this a common problem with a known fix? - perhaps to install an older distributer

I can't find the address to request a wiring diagram. Who do I contact?

Thanks for listening.

Derfa7

 

[ghnl]

Welcome to the AlfaBB. It is good that you told us what color your Spider is. That should help us diagnosis it. But even better would be some photos...

Your car (aka Series 3 1982 - 1989) has Bosch L-jetronic. It has two computers - one for ignition & one for fuel injection. And to confuse the matter one of those computers will have a label that says Motronic. But trust me, the system is L-jetronic. Later Spiders (Series 4 1990 - 1994) have one computer combining the ignition & fuel functions into the one computer and that system is Motronic. Click on the link in my signature to a page of DIY diagnosis info about the L-jet system in our cars. (you may need to click the down the arrow to see the whole signature)

Reading your description of how your car is misbehaving makes me think there is a problem with the large air duct across the top of the engine. All air entering the engine must pass through the Air Flow Meter (AFM). Any air entering beyond the AFM is called false air - unmetered. This messes up the computer's calculation for how much fuel to inject. Either a joint of the large air duct has come loose or there is a large split in the accordion shaped section near the AFM. When you try to throttle up the engine rocks on its rubber mounts, one of those faults opens up & the engine gets a big gulp of false air. The engine rocks back, the fault closes the computer tries to inject gas, the engine rocks up again and it won't run right. The fact that it'll start & idle OK means the flywheel sensors, ignition system and FI system are likely all working OK.

Check your 'conversation' (aka private message) for a wire diagram.

And don't neglect to post some photos - otherwise we may have to send Guido over to have a talk wid youse...

 

[radamm]

Having driven through some rain could the distributor cap picked up some moisture?

 

[vintagemilano]

Awesome reply Eric, that’s bang on.

 

[spiderserie4]

So far I have found the battery ground, the ground strap on the bell housing, and the black wire cluster on the right valve cover. Others???

As you are cleaning grounds (always a good idea on a 35 year old car, whether it has anything to do with your particular problem or not!) the main ECU ground bundle is on passenger side of the head, near #4 injector.....unbolt, clean up, replace with some dialectric grease.
before and after:


Check first what Eric suggests, the big air hose, as it sure sounds like your problem is that!...they come loose or even split, sometimes as a result of sagging motor mounts (as the mounts wear/squash, the engine torques more to the passenger side and stresses that already fairly stiff accordian hose)
a simple visual might tell you, if the engine mounts looked 'bloated' ro cracked..
Other clues to bad mounts are: the oil pan is not parallel to the road (although the top of the engine is slanted, the oil pan is level, that is the design)
and/or the front crank pulley is too close to the front sway bar.

 

[pantera928]

I am curious about it just starting this problem after sitting over night and with rain. Could easily be moisture related or a MAF sensor or a TPS issue. Definitely check for air leaks and grounds as previously mentioned. Those are easy fixes versus others.
Tach issues could be a sensor also but that sensor should not affect the ECUs as there is another sensor for that, You might check those connections. They are both near the firewall by the washer fluid reservoir.
Where are you located? I did not even know that Italian Car Day was still on this year or I might have gone.
Keep us posted and good luck

 

[derfa7]

Hi Everyone:

I am new to the Bulletin Board, but have had lots of Alfas in the past--all with either Spica injection or Webers.

Recently, I got a black 1985 Alfa Graduate that my sister bought new. It has been babied and regularly serviced and it in top condition.

Last month, I drove it to the Italian Car Day in Atlanta--a 200 mile trip. The car ran beautifully even through some rain.

Once home, the car sat outside overnight and by the next morning all hell had broken loose. I have listed the details of the Great Exploding Spider below. Any diagnostic or repair ideas that would help me get the car back on the road would be appreciated. So here goes:

THE CAR: 1985 Alfa Graduate, Black, with 119,000 miles, well maintained.
Jetronic fuel injection with a flap-operated air flow meter.
The distributor has no primary wire or vacuum advance. The bell housing has two sensors on the passenger side.

(What is this system called: L-Jet? Motronic? I bought the Probst book but don't know which section to read.)

SYMPTONS: Car starts well and idles well, but just above idle the car runs rough and misses. At about 1/2 throttle the engine runs and quits, comes close to dying--but never quite does. Above 1/2 throttle on up to wide open the engine still runs poorly then dies, then runs, etc. Every time the engine "catches" there is a hug backfire--a long flame and plume of black smoke out of the tail pipe. It is all very violent and frequent and could provide the background effects for a war movie.

The tachometer seems to read OK at idle but clearly reads low above idle and takes a huge and sudden jump up just before every exploding backfire.

REPAIR PLAN:
Plan?
First I plan to clean all the grounds. So far I have found the battery ground, the ground strap on the bell housing, and the black wire cluster on the right valve cover. Others???

After the grounds, I have no ideas except to "shotgun" parts replacements.

Assuming there are relevant fuses, where are they?

Is this a common problem with a known fix? - perhaps to install an older distributer

I can't find the address to request a wiring diagram. Who do I contact?

Thanks for listening.

Derfa7

 

[derfa7]

hi everyone:
this is an update on the great exploding graduate.

first, to answer pantera's question:
i live in macon georgia which is close enough to attend italian car day in norcross.
last year the meet was cancelled 3 times due to weather and this year because of the virus . but last month john, the frustrated organizer, figured that , since he had the trophies , he would put together a meet via telephone messages.
it was at the ferrari dealership with good attendance and mid-level anti-covid measures.
there is a video on the website for italian car day (i hope). my car is the only black spider.
what will happen in 2021 is anybody's guess .

now, about my '85 graduate ( idles ok, runs poorly mid range, backfires, tach goes crazy ).

thanks for all your suggestions- i have only begun my search and repair work.

the accordian tube looks new or recent - no leaks and has good clamps.
also, the engine mounts are probably ok because the oil pan is parallel to the road and the front pulley is not too close to anything it could hit

while i had the tube off i tried to activate the fuel pump by moving the air flow flap with the ignition on --- no result.

i also tried running the engine above idle while trying to get smooth running buy moving the flap by hand. --- no effect at all.

then i pulled off the harness connector at the air flow meter and the engine died instantly. when i plugged it back in, it started and was back to abnormal.

i removed and cleaned the grounds at the bell housing and at the right rear valve cover.
one 10mm bolt was stripped (YEAAAAAA) so i tapped it up one size. ... all to no improvement ( not yeaaa).

next will be more work on more grounds, but i have a question i wish i didn't have to ask :

 

[ghnl]

while i had the tube off i tried to activate the fuel pump by moving the air flow flap with the ignition on --- no result.

As expected. The Spider's AFM does not have a switch to activate the fuel pumps. The GTV6 does.

i also tried running the engine above idle while trying to get smooth running buy moving the flap by hand. --- no effect at all.

I assume you did this with the air duct disconnected. (how else would you be able to move the AFM's flap?)

but i have a question i wish i didn't have to ask...

The answer is 42.

 

[derfa7]

whoops, i tapped the wrong button and my text went away. here is my unfortunate question: while i was waiting for my l-jet manual to download i actually read the owner's manual. it says not to charge the battery above 6 amps and never use a high amp start mode. of course, i had charged at 40 amps AND started with 100 amps. ---- in my defense, i was able to drive 200 flawless miles after that. so , did i fry anything costly ?

thanks all derfa7
/

 

[derfa7]

As expected. The Spider's AFM does not have a switch to activate the fuel pumps. The GTV6 does.



I assume you did this with the air duct disconnected. (how else would you be able to move the AFM's flap?)



The answer is 42.

yes, the tube was off. ... glad you remembered 42, but hitchhiking is not my favorite thing right now.

 

[pantera928]

hi everyone:
this is an update on the great exploding graduate.

first, to answer pantera's question:
i live in macon georgia which is close enough to attend italian car day in norcross.
last year the meet was cancelled 3 times due to weather and this year because of the virus . but last month john, the frustrated organizer, figured that , since he had the trophies , he would put together a meet via telephone messages.
it was at the ferrari dealership with good attendance and mid-level anti-covid measures.
there is a video on the website for italian car day (i hope). my car is the only black spider.
what will happen in 2021 is anybody's guess .

now, about my '85 graduate ( idles ok, runs poorly mid range, backfires, tach goes crazy ).

thanks for all your suggestions- i have only begun my search and repair work.

the accordian tube looks new or recent - no leaks and has good clamps.
also, the engine mounts are probably ok because the oil pan is parallel to the road and the front pulley is not too close to anything it could hit

while i had the tube off i tried to activate the fuel pump by moving the air flow flap with the ignition on --- no result.

i also tried running the engine above idle while trying to get smooth running buy moving the flap by hand. --- no effect at all.

then i pulled off the harness connector at the air flow meter and the engine died instantly. when i plugged it back in, it started and was back to abnormal.

i removed and cleaned the grounds at the bell housing and at the right rear valve cover.
one 10mm bolt was stripped (YEAAAAAA) so i tapped it up one size. ... all to no improvement ( not yeaaa).

next will be more work on more grounds, but i have a question i wish i didn't have to ask :

So, you are about an hour from me.
what is the question you wish you did not have to ask?

yes, the tube was off. ... glad you remembered 42, but hitchhiking is not my favorite thing right now.

42?

 

[mmarvi]

42?

Apparently not a Hitchhikers Guide to the Galaxy fan.

Mo in New Jersey
Almost, but not quite entirely unlike tea.

 

[derfa7]

So, you are about an hour from me.
what is the question you wish you did not have to ask?

42?

the text went poof. so; before driving the 200 miles i charged the battery at 40 amps and boost started the car at 100 amps.
have i fried anything expensive ?
drop ln if you are in macon.

 

[pantera928]

the text went poof. so; before driving the 200 miles i charged the battery at 40 amps and boost started the car at 100 amps.
have i fried anything expensive ?
drop ln if you are in macon.

Well, if you drove that far after charging, I would think you have not fried anything.
I have some spares from an 85 if you want to try a few things. What part of Macon?

 

[pantera928]

Apparently not a Hitchhikers Guide to the Galaxy fan.

Mo in New Jersey
Almost, but not quite entirely unlike tea.

I guess not. But I just looked it up.

 

[derfa7]

Well, if you drove that far after charging, I would think you have not fried anything.
I have some spares from an 85 if you want to try a few things. What part of Macon?

will keep spares in mind. thank you . hartley bridge exit from i-75 right at i-475 southern split. 6369 houston rd 478 786 0275

 

[pantera928]

will keep spares in mind. thank you . hartley bridge exit from i-75 right at i-475 southern split. 6369 houston rd 478 786 0275

Okay, down near the airport. I have a spare ECU and probably several other parts that we could trial if needed.

 

[pantera928]

first, to answer pantera's question:
i live in macon georgia which is close enough to attend italian car day in norcross.
last year the meet was cancelled 3 times due to weather and this year because of the virus . but last month john, the frustrated organizer, figured that , since he had the trophies , he would put together a meet via telephone messages.
it was at the ferrari dealership with good attendance and mid-level anti-covid measures.
there is a video on the website for italian car day (i hope). my car is the only black spider.
what will happen in 2021 is anybody's guess .

Just saw this. Was looking on my phone last night and missed it. Sorry that I missed Italian Car Day.
Just looked at the video and did not spot your car but did see Tommy Orr's Green S4. Maybe i just missed yours.
Thanks for sharing

 

[derfa7]

sounds good . i am still on the grounds, but loosing hope. fred