81'x FI Struggles, shut down with black smoke

81x

X'ing Fixing
A little progress.
I've disconnected the vacuum line, but at the far edge as the edge on the pressure regulator didn't came out easily. no scent or fuel trace where found.
Next test is with pressure gauge only?

For the CTS:
On the manual that @Dan Sarandrea (Phila) posted, it says to pull out the plug from the ECU.
20201017_103732.jpg


Is that gigantic plug?
20201017_102204.jpg


Just loosen those two bolts and pull out?
First time I'm doing it, want to be careful.

The sensor and wires seems complete
20201017_102251.jpg

So dirty o_O

BTW, those are the original clamps I refer to
20201017_104437.jpg

But it those seems to be clamping a non pressure lines.
 

Rodger

True Classic
Just loosen those two bolts and pull out?
First time I'm doing it, want to be careful.
There is a metal clip on the right side of that plug. Undo that and the giant plug rotates up and out to the left.
 
  • Like
Reactions: 81x

81x

X'ing Fixing
The CTS for the fuel injection system is on the thermostat housing
The drawing dan posted shows those sensors on the back of the engine, on the other hand the item on MWB website looks like the one i think you refer to (the hex head is thinner). So which one is the correct one?
20201017_214453.jpg
 

ng_randolph

Bjorn H
The one you just showed with the yellow connector is the correct one. The drawing Dan posted is from the "Fuel Injection Diagnosis" manual. This manual is not specific to the X1/9 (it covers both the 1500cc SOHC engine and the 2000cc DOHC engine), so some of drawings are not accurate for the X1/9.
 
  • Like
Reactions: 81x

lookforjoe

True Classic
Just looked back at this:

looks like some serious rust in that lower crossmember area(!) What's the rest of the body like?

20201017_102204.jpg
 

81x

X'ing Fixing
Happy to say that the rest is quite good.
Still at the previous owner, that car was stripped down and welded where needed, can't tell why they skip it.
Those holes are for the spare wheel mount that broke and just lay there. Beneath that it's the poor isolation material that crumbling down. I agree it doesn't looks good and need to be fixed.
 
Last edited:

81x

X'ing Fixing
Another trial, my friends.
Follow Dan's suggest and checked the terminal in the ECU plug.
Of i did it right, on "2000" mode it shows 1200-1900 ohms but immediately dropped to "1" like I'm not touching anything. Every time it blinked a difference reading and dropped to 1.
At "20k" mode it shows 3.26k ohms at stood there.
The car is at rest of course so the coolant temp is around 25C degrees so it spouse to show between 2000-3000 ohms.

But I discovered a probably important issue:
The terminal was a bit corroded! How?
And I guess it's a reason for mis-reading, right?
20201019_192436.jpg


I will give it a clean with contact spray and a fine brush a start the car.
 

Dan Sarandrea (Phila)

Waitin' On Parts...
Another trial, my friends.
Follow Dan's suggest and checked the terminal in the ECU plug.
Of i did it right, on "2000" mode it shows 1200-1900 ohms but immediately dropped to "1" like I'm not touching anything. Every time it blinked a difference reading and dropped to 1.
At "20k" mode it shows 3.26k ohms at stood there.
The car is at rest of course so the coolant temp is around 25C degrees so it spouse to show between 2000-3000 ohms.

But I discovered a probably important issue:
The terminal was a bit corroded! How?
And I guess it's a reason for mis-reading, right?
View attachment 37647

I will give it a clean with contact spray and a fine brush a start the car.
Over the years folks have reported occasional issues with "the big plug." It is thought that if one is overly enthusiastic about cleaning their engine bay to the point of hosing it down, or on cars where the rain tray has been removed, or on cars that have spent a LOT of time outdoors, water can wick down from the part of the FI harness at or near the top of the engine, travel down the large bundle of wires and seep into the plug, causing corrosion.

As your car has significant chassis corrosion in the spare tire compartment area where the FI controller lives, it's not a total shock that the big plug is showing some green fuzz. The wiring to the FI CTS is the wire from the corroded connector to one pin on the CTS, across the CTS and then to ground, which for this particular circuit is one of the two (can't recall which ATM) grounds that attach to cam box cover. If your leads are long enough you can check resistance of each segment of the circuit.
Segment 1: from that corroded contact to one of the two pins in the FI CTS connector plug.​
Segment 2: from the "other" pin of the FI CTS connector plug to the correct one of the two grounds on the cam box cover.​

There may be a reference to tell you which pin is which on the FI CTS connector plug, but I do not have that info handy. But it's not hard to figure it out with the multimeter.

Looking at the pix you posted of the yellow plug (with FIAT molded in the plastic) at the FI CTS, I noticed something. My car is an '86 so there might have been production differences comparing very early FI cars to later cars, but on my car all of the plastic plug housings are black, and all of the wiring inside of the FI harness is white. Compared to your car where the plug is yellow and the plug's wires seem to be conventional CAVIS (the company that made a lot of Bertone's wiring harnesses) colored and striped wires. Could be that's how it came from the factory, or could be that the plug was replaced and if your wiring resistance checks uncover a problem, the problem could be how that "foreign" plug was grafted into the original harness.
 
Last edited:
  • Like
Reactions: 81x

lookforjoe

True Classic
Another trial, my friends.
Follow Dan's suggest and checked the terminal in the ECU plug.
Of i did it right, on "2000" mode it shows 1200-1900 ohms but immediately dropped to "1" like I'm not touching anything. Every time it blinked a difference reading and dropped to 1.
At "20k" mode it shows 3.26k ohms at stood there.
The car is at rest of course so the coolant temp is around 25C degrees so it spouse to show between 2000-3000 ohms.

But I discovered a probably important issue:
The terminal was a bit corroded! How?
And I guess it's a reason for mis-reading, right?
View attachment 37647

I will give it a clean with contact spray and a fine brush a start the car.
Be very careful with any abrasive (brush) when cleaning these, the coating is likely already compromised, and brushing it will only make it worse. Contact cleaner & a folded dollar bill is about as abrasive as you want to get. Terminals can be replaced without too much headache, however you do need good electrical crimping pliers and the replacement terminal(s) - the newer ones have a spring tensioner around the prongs, and 2 wider prong vs. 4 smaller.
 
  • Like
Reactions: 81x

81x

X'ing Fixing
@Dan Sarandrea (Phila) you could be right about the corrosion, I just wonder why that terminal is the only one to be corroded? Weird.
Could it's wire be faulty as well?
For the sensor plug, my guess that it is not original, it looks like someone mess with is and covered it with isolation tape, the rubber boot is gone also.
The ground from the sensor to the body works good, I will try your other suggestions. Thanks!

@lookforjoe thanks for the warning, I thought of cleaning with a toothbrush but I'll go easier at first.
Are those replacing terminals generic or something particular?
 

lookforjoe

True Classic
@Dan Sarandrea (Phila) you could be right about the corrosion, I just wonder why that terminal is the only one to be corroded? Weird.
Could it's wire be faulty as well?
For the sensor plug, my guess that it is not original, it looks like someone mess with is and covered it with isolation tape, the rubber boot is gone also.
The ground from the sensor to the body works good, I will try your other suggestions. Thanks!

@lookforjoe thanks for the warning, I thought of cleaning with a toothbrush but I'll go easier at first.
Are those replacing terminals generic or something particular?
Bosch used them for many EFI systems -TE technology - Junior power timer grabbed the first listing I saw, search around for smaller quantities. I'd change the two at the sensor also, and replace the housing if its questionable.

 
  • Like
Reactions: 81x

Dan Sarandrea (Phila)

Waitin' On Parts...
@Dan Sarandrea (Phila)
The ground from the sensor to the body works good, I will try your other suggestions. Thanks!
The ground for the FI CTS should be one of the two that terminate onto cam box cover studs and nuts, not to the body. As long as where it's grounded is a good ground that's what counts, but if you're looking to "de-molest" an FI system that seems to have been previously molested, you might as well put it back to original.
 
  • Like
Reactions: 81x
I would recommend using CAIG DeoxIT to clean the corroded connector. Works great for cleaning up corroded conductors.
 
  • Like
Reactions: 81x
Top