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164 12V 1990 / GTV 916 2l TS 1999
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Discussion Starter · #1 ·
Hey guys!

I have a big problem since the last 2 weeks. The weather is now cold & wet. Since then i have a issue with my engine stalling/Misfiring. When its warm and dry outside she runs like nothing is wrong. Funny thing is: Its mostly only between 60-70° Celsius Watertemp this happens. When the engine ist hot or cold everything is fine. But between that its hell. Cold and moist weather makes the issue even bigger.

My first guess was a problem with the ignition system. So i did the following things new:
- Ignition coil
-Ignition cables

They were very old anyway so it wasnt wasted money.

Distributor cap is dry and the rotor also new. Next try was the Cranksensor. I find it very funny that the rpm needle bounces nearly to zero when it stalls. And since cranksensors are sensitive to temperture differences i gave it a try. But without succes. Problem still remains the same.

Car is a 1990 164 3l 12V EU Spec.

I mean there is not really much complicated stuff in these cars. So im a little confused right now. Maybe someone of you have encountered this problem before.

I have a little video for you to get a better picture.

 

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2015 Chevy (Holden) SS, 1989 Milano (Shankle Sport), 1991 164S
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Try cleaning, and protecting with dielectric grease, EVERY electrical connection in the engine compartment as a first simple start.
 

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1991 164L
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Does the coolant over temp red light come on and flicker as seen in your video sometimes when the tach needle fluctuates? That acts like you are having a loss of electrical power through the ignition switch contacts. If so I suggest you jumper red 12v power wire to brown and pink wires in connector to ignition switch to bypass contacts in switch.
 

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164 12V 1990 / GTV 916 2l TS 1999
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Discussion Starter · #4 ·
Try cleaning, and protecting with dielectric grease, EVERY electrical connection in the engine compartment as a first simple start.
Thats an idea. I will check the wires and connections.

oes the coolant over temp red light come on and flicker as seen in your video sometimes when the tach needle fluxgates?
Nope. The light didnt flicker a single time when these cut outs occur. And the tempature from the gauge seems plausible. Never jumps or signales something strange.


Little background: The car was sitting for ~15 years. Head gaskets were shot. The engine is completley refurbished, everything is new now or overhauled.
Only things that are old are:
-Injectors
-Temperaturesensor
-fuel pressure regulator
-MAF

The cars runs very well and with plenty of power except for these cut outs.
 

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1991 164L
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Still looks like a loss of electrical power for the tach needle to drop off like that. It gets signal from coil. Check that connection to ignition switch for corrosion/burned contact.
 

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I suggest you also use a spray contact cleaner to clean the wire leads/connectors to the coil, and then clean and tighten the engine to chassis ground cable at both ends. Check the coolant temperature sensor connector, see if any coolant or moisture is leaking onto that wiring.
 
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While everything above is certainly necessary, I second Dave's thought about the coolant temperature sensor.
 

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While everything above is certainly necessary, I second Dave's thought about the coolant temperature sensor.
What I'm thinking about is his comments about this happening mainly in wet, cold weather. If it had a Lucas system, I'd understand it completely! ;) It is probably ignition related, on the coil or ignition feed side, like Steve indicates.
 

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164 12V 1990 / GTV 916 2l TS 1999
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Discussion Starter · #9 ·
Ok guys, i testwise installed a new ground cable (The big one on the transmission because the old one was covered in
verdigris) and checked the relais sitting next to the ignition coil. With no change.

I will try steves tipp next time when i have no succes with it. Before that i will try it with a new tempaturesensor. A friend mentioned that he got a very similar issue with his fiat coupe. In the end it was a faulty temperturesensor. That thing is not really expensive so its worth a try.

Its so weird... Its always, always precisely between 60-70° Celsius.
 

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1991 164L
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I ain't buying a bad Bosch coolant temp sensor temp sensor causing his problem as it is mainly for cold starting. Once engine is warm you can disconnect it and engine will run fine maybe just a little lean. It has about 3k high resistance cold to enrich starting and warm up. Once warm resistance goes down to about 200-300 ohms. Prove me wrong, warm up engine and disconnect it and see if engine stops. Don't burn yourself on radiator hose.

OBTW it is not the sensor next to timing belt cover that one is for the temp gauge and over temp red dot light only not for fuel injection. That Bosch fuel injection sensor is hidden in mid thermostat housing under the radiator hose attachment to thermostat outlet.
 

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My Speedo does this, it's does not run rough and yours doesn't sound like it's missing or the engine is cutting out either, it just looks like a bad connection to the binnacle somewhere, when mine has done this (twice) a gentle but firm slap on top of the unit seems to make it go away
 

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164 12V 1990 / GTV 916 2l TS 1999
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Discussion Starter · #12 ·
Alright, seems like steve was right. New (Both) tempature sensor and the problem still remains the same. I will look into the ingition switch today. Are there any relais that are connected to that circuit? Also i will install a new ground cable.
 

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1991 164L
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Yes, two relays for fuel pump and motronic ECU computer. Both on top radiator support next to ignition coil. Red stripe one w/diode for both ECU, injectors and power to fuel pump relay.

See wiring diagram: 12v Motronic Wiring (1).pdf
 

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1991 164L
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Wait a minute, have you verified you have good grounding of Fuel Injection system wires G131 grounding bolts to end of intake plenum and that intake plenum is also grounded to valve cover or engine block? Later models intake plenum set on rubber mounts so not grounded to engine unless a ground strap from throttle body allen head bolt to rear of head.
 

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Discussion Starter · #15 ·
So... new ground cable installed, still the same. The ignition switch and cables are looking good, nothing burned or loose.

The drive back home from my workshop was a nightmare. Very foggy weather this evening, so it was stalling like hell. And: Not before 60° Celsius. Cold she was running fine despite the weather conditions.

Wait a minute, have you verified you have good grounding of Fuel Injection system wires G131 grounding bolts to end of intake plenum and that intake plenum is also grounded to valve cover or engine block? Later models intake plenum set on rubber mounts so not grounded to engine unless a ground strap from throttle body allen head bolt to rear of head.
Pretty sure thats good, yes. I have cleaned that from oxidation and used new fasteners. The intake plenum is not mounted on rubber mounts. So ground there should be fine.

Vehicle Auto part Car Engine Automotive super charger part

The two relais looking good as well. I guess you mean these?

Engine Auto part Vehicle Automotive engine part Car


The car is on the road for ~6 months now and i never had this issue. Only now in cold weather. I also tested the MAF. While running i pulled the plug and the engine instantly stalled.


BTW, what is very weird to me is that since the temperature sensor (For the gauge) is new the red warning light is always on. But other than that its working fine.
 

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We owned a 164 years ago, a 24 valver, and I note the position of the ignition coil in photos of 12 valve motor cars. The coil appears to be installed horizontally just in front of the distributor, correct? Is it mounted securely, are the low and high tension wires securely seated with boots on them?
I don't recall this detail either, but is there (was there) any type of splash shield on the bottom of the chassis underneath that side of the engine bay? I would carry a can of WD40, or other spray moisture displacer, with me, during these conditions, and spray the coil connections, the wire leads and the crown of the coil and distributor cap with WD40, then step back and see if you get any results.
 

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1991 164L
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So... new ground cable installed, still the same. The ignition switch and cables are looking good, nothing burned or loose.

The drive back home from my workshop was a nightmare. Very foggy weather this evening, so it was stalling like hell. And: Not before 60° Celsius. Cold she was running fine despite the weather conditions.



Pretty sure thats good, yes. I have cleaned that from oxidation and used new fasteners. The intake plenum is not mounted on rubber mounts. So ground there should be fine.

View attachment 1659466

The two relais looking good as well. I guess you mean these?

View attachment 1659465


The car is on the road for ~6 months now and i never had this issue. Only now in cold weather. I also tested the MAF. While running i pulled the plug and the engine instantly stalled.


BTW, what is very weird to me is that since the temperature sensor (For the gauge) is new the red warning light is always on. But other than that its working fine.
Prolly you got the wrong gauge/red light sender for the 91-93 164 so red light dot will stay on. I bet you got one for GTV6/Milano(75) and 94-95 164. There is one of the correct ones for 91-93 on Taiwan ebay now but shipping very high.

You can turn out the over temp red dot light by disconnecting wire (small terminal) from sender and ground it to engine or chassis to keep red dot off.

I guess you need to jump red wire to brown and pink wires at ignition switch connector and see if your cutting out issue stops.
 

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Prolly you got the wrong gauge/red light sender for the 91-93 164 so red light dot will stay on. I bet you got one for GTV6/Milano(75) and 94-95 164. There is one of the correct ones for 91-93 on Taiwan ebay now but shipping very high.

You can turn out the over temp red dot light by disconnecting wire (small terminal) from sender and ground it to engine or chassis to keep red dot off.

I guess you need to jump red wire to brown and pink wires at ignition switch connector and see if your cutting out issue stops.
Steve, isn't there an air temp sensor built into the AFM? I know the Motronic system on my S4 Spider has one, and the fault code on that is 1221, as I recall. What if that temp sensor isn't reading the colder air correctly??? Have you seen that happen with any of your 164s?

EDIT: Checking the 164 forum, and the Motronic fault codes, looks like that would be 1225 on the 164. See
file:///C:/Users/Dave/Downloads/Alfa%20164%20Motronic%20Self-Diagnosis%20(1).pdf
 
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Yes there is an air temp sensor in AFM.
 

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Yes there is an air temp sensor in AFM.
Well then, based on the symptoms described, I think he should run the diagnostic routine using the pushbutton, and see what codes pop up. After all, this rough running seems to be connected with ambient air temperature. I could be wrong, but I think it's worth a try. If he has access to another AFM, he could change them out and test by substitution, also.

Relinquished, what do you say?
 
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