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Discussion Starter #1 (Edited)
HI all,

I have started to get a problem with my 146 1.8ts.

First thing in the morning and after I have let it stand for a while this happens, while driving it will suddenly lose power and start to backfire. this only happens for a few hundred meters or so, but I think its getting worse. Also when I come to a stop, the revs will bounce up to around 1500 rpm and then settle back down to around 850-900.

Anyone any idea what this could be?
 

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That would be the TPS, Throttle Position Sensor, it's on the side of the throttle body, it doubles up as the Idle Control Valve and this is the side of it at fault.
 

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Discussion Starter #5
I took off the cable that is connected to the MAF, this seems to have rectifed the problem, the power is back and no backfires/misfires, I think I need a new MAF or is there some way to clean it.

Please advise....
 

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Ah well, if it clears with the MAF unpluged then you've nailed it, get a BOSCH one not a replica, the cost of it is discerning but in time well worth it.
 

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i think my 146 has the same problem. affects more when room temperature suddenly decreases. sometimes it almost refuses to run. i have to really step on the accelerator, run a bit and then the symptoms are gone. strangely, when i took the car to the mechanics a year ago they didn’t detect anything.

thanks for all the info!
 

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Alfizta, what's your temp guage reading whilst the engine is running?
you mean the engine temp? (i’m not english) this happens when it’s bellow 40 ºC. but in very cold days, and when the engine is running for a while and still under 40 ºC i don't notice anything. yesterday the day was hot, the engine was around 80 ºC, and actually felt it was losing power :confused:

like i said, i think it doesn’t have directly to do with outside temperature. i notice more when last day was hot and next cold, or the vive-versa. i.e. during winter i can’t tell a thing cause it’s always cold.
 

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you mean the engine temp? (i’m not english) this happens when it’s bellow 40 ºC. but in very cold days, and when the engine is running for a while and still under 40 ºC i don't notice anything. yesterday the day was hot, the engine was around 80 ºC, and actually felt it was losing power :confused:

like i said, i think it doesn’t have directly to do with outside temperature. i notice more when last day was hot and next cold, or the vive-versa. i.e. during winter i can’t tell a thing cause it’s always cold.
If those figues are correct then I think your thermostat is faulty, replace that first and see if the engine runs at 90'C, then we can start with the fueling problem.
 

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If those figues are correct then I think your thermostat is faulty, replace that first and see if the engine runs at 90'C, then we can start with the fueling problem.
:confused: that “40 ºC” only happens when starting the engine or in very cold days, running at very low rotation and down hill... normally it runs between 80 and 90 ºC. i don’t see why the thermostat should be faulty. :confused:
 

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Even on a cold day, after the engine has been running for 5 minutes it should be sat dead on the 90 mark, if it's droping to 80 or not reaching that on cold days the the thermostat will be stuck open. this then cools the engine too much and as soon as the engine goes below 65'C the ECU ignores the Lamda and MAF and just chucks in more fuel as if it was a choke, this will then flame out your engine and give you the symptonms your geting.
 

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dropped the car in my alfa dealer yesterday. they didn’t do much. i think i could have done it myself. they opened the throttle body, cleaned it and putted all together again. about 40 euros for the job. i don’t know if the car is good, cause it didn’t have any symptoms by the time. but the mechanics say there shouldn’t be any problem anymore… hope not.

if you read this, thanks again smaky.
 

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I don't think that would have cured it, if they put it down to throttle body then it's the first one I've heard of on the 1.6, the IAC is common and that is on the throttle body and causes fluctuating idle but I would still get the thermostat done.
 

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hi there!

i hope the weather changes soon. only that way i'll find out :D it's been cold for summer here. and the car usually goes mad in hot days.

and pardon my ignorance,... aren't there temp sensors that could be faulty?
 

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I had the same symptoms (sp) on my 1800.

Took the lead off the air flow and went away, so replaced the afm with another one i had (good one) and it came back.

Dissconnected the lamba sensor and all ran fine.

Left it dissconnected for a long while then when i connected it back up the missfire came back.
 

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When the temp sensor fails you either get full scale deflecion, or it won't budge the needle, plus they seem to be very robust on the 145/146s, I've never see a faluty temp sender since the cars were released in '94, I still hold out that your thermostat is at fault.
 
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