dirty idle control valve? or just throttle body in general?
Technical Stuttering loss of power on acceleration
- Thread starter DRSIK
- Start date
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Technical Stuttering loss of power on acceleration
Does anyone know what was the culprit for this one ?
I have something that from the description sounds very similar.
in my case, the following parts were swapped just a year ago (when diagnosing a different issue, which turned to be a vacum leak)
MAP
lambda
TPS
plugs
coils
leads
fuel pump
vacum pipe from MAP to engine
Ive also checked the resistance across the CTS that is at the top of the thermostat, and it is changing as the coolant gets hotter, but i dont know if the readings are within spec (because i didnt know the temperature, neither the spec)
just to re-iterate, in my case.
when cold
car seems to be ok, both idle as well as revving the engine and theres power delivery.
when hot
idle is ok. but engine stalls if i open the throtle.
the strange thing about it is that just a couple of weeks ago. i drove it for a 40 mile return trip and it didnt miss a beat. admitedly it was mostly motorway driving, but the next time it started it barely made it out of the housing estate before it was turned around.
I have something that from the description sounds very similar.
in my case, the following parts were swapped just a year ago (when diagnosing a different issue, which turned to be a vacum leak)
MAP
lambda
TPS
plugs
coils
leads
fuel pump
vacum pipe from MAP to engine
Ive also checked the resistance across the CTS that is at the top of the thermostat, and it is changing as the coolant gets hotter, but i dont know if the readings are within spec (because i didnt know the temperature, neither the spec)
just to re-iterate, in my case.
when cold
car seems to be ok, both idle as well as revving the engine and theres power delivery.
when hot
idle is ok. but engine stalls if i open the throtle.
the strange thing about it is that just a couple of weeks ago. i drove it for a 40 mile return trip and it didnt miss a beat. admitedly it was mostly motorway driving, but the next time it started it barely made it out of the housing estate before it was turned around.
mine was also doing the same ,,changed all the usual bits,,,and found the car runs better after i took the TB off and properly cleaned it and had found that the pipe where the oil breather attached was clogged after rebuilding used new gasket paper with a fi e smear of rtv sealant and also fitted a proper ICV a good oem branded one not one of those cheap crap ebay chinese ones also fitted ngk plugs at the correct gap for the 1.1 sei 0.7mm and also fitted a new magnetti marrelli lambda sensor again dont buy cheapo ebay junk parts stick with oem these cars ive found dont get on with non oem also run the car on super unleaded preferably shell and also keep the oil changed regularly took me a long time to get mine sorted ....but id deffo 1st of all take the TB off anfd properly clean it if its an SPI the tb splits in two parts and make sure its cleaned inside and out through all the pipes etc and reassemble carefully and if using a sealant as a gasket go easy and only a thin smear ,issues can also happen if the tb is sucking in air due to gasket/seal leaks to quickly check is to spray some carb/brake cleaner or wd40 around the TB when the car is running and listen for any changes to the idle you can also spray around hoses to also check for leaks .....also check your spark plugs are clean and gapped properly and dont waste money on so called fancy plugs
ive cleanred the thrthle body and as a result all the hoses got new clamps (because the old ones were the crimp type that is not reusable.
also fitted new cranshfat sesnor and new coolant sesnor.
still bogs down when hot.
did the brake cleaner spray around the hoses near the TB and also no issues there.
i have no idea what to look at next. even compression test seems pointless since the car would be cold then i do that.
also fitted new cranshfat sesnor and new coolant sesnor.
still bogs down when hot.
did the brake cleaner spray around the hoses near the TB and also no issues there.
i have no idea what to look at next. even compression test seems pointless since the car would be cold then i do that.
i'd not be so sure on that tbh.. Do a cold test and then get it nice and hot, ideally the temp it starts being silly and then do another test, see if it changes. Things move around with heat cycles, it really could be early head gasket failure and if you keep going you'll get to doesnt work cold either.
I would say as well just because parts were changed within a year don't assume they still work, even more so depending on what stuff was used to replace them. Remember even if you use genuine parts at this point most of them will have been sat on a shelf in god knows what storage conditions for who knows how many years. It might be a new sensor, it might be a 15 year old sensor that spent 10 years in a damp unconditioned storage unit - you just don't know. So really if its been working fine for i assume about a year you need to start diagnosing from the start to eliminate things. Which i hope without reading this whole thread back should give you some stuff to try. So start with the easy/free things to check - compression, timing etc
Hi Tuga. As Blu says, the heat can make head gasket leak, missfires etc. Also check vacuum line to brake servo is in good condition.
Only other thing i'd add to the list above is that cheap coil packs are faulty from the start and can be intermittent. Buy branded coil packs only. I've learnt this from experience. The coil packs can also be affected by water, after the wet winter we've had this could be a potential cause of failure.
Compression testers are not expensive and useful to have.
