temp sensor

[nismoz]

Will the temp sensor on a gst cause them to run extremely rich as it will on some cars?thx

 

[92AWDHX40]

A sensor that makes it run rich, fill us in on that, I never knew once sensor that makes it run rich just the 02 sensor being bad.

 

[spyderdrifter]

The only way the ECT would have anything to do with running rich, would be if it was bad, therefore making your ECU think the engine is still cold and requesting more fuel to warm the engine. I think at that point the ECU is in open - loop and automatically requests more fuel (could be closed, but I'm sure it's open).

 

[nismoz]

The only way the ECT would have anything to do with running rich, would be if it was bad, therefore making your ECU think the engine is still cold and requesting more fuel to warm the engine. I think at that point the ECU is in open - loop and automatically requests more fuel (could be closed, but I'm sure it's open).

You understood that well, yes that's what I'm asking.
Does our ECU use the temp sensor as does Nissans, Fords, etc to determine fuel curves under closed/open loop modes?

My real prob is, changed MAF, upstream O2! Car runs pig rich as it hits boost and stays there, upon 5.5k it will sometimes buck like shyt also. No boost leak either what gives?

 

[spyderdrifter]

I honestly can't tell you one way or another about DSM ECUs behaving the same as other makes. If you've replaced that many components, I'd take a multimeter and test the ones you haven't replaced to narrow down the likely culprit to include the ECT, injectors, TPS, & IAC/ISC.

 

[92AWDHX40]

ECT will speak to the ECU causing a hard start, sound like a O2 sensor isn't working, again like said, I have no idea about other cars but never knew it to be the coolant temp sensor.

 

[nismoz]

Ets,ect. Dude i work on bmws an chevys n all they use terms like dme an hfm... Why cant they jus call them all by the same name.... Anywho what are the sensors by name and it starts easily as it should only prob is as boost comes.

 

[spyderdrifter]

Engine Coolant Temp sensor
Throttle Position Sensor
Idle Air Control sensor/ Idle Speed Control sensor

 

[92AWDHX40]

So the boost comes on and you get rich is the car tuned do you have a wideband? What injectors sounds like you running rich and cant figure out why, is that what im understanding.

 

[GST with PSI]

How do you know the car is running rich? Do you have a wideband, or some way to monitor your A/F ratio?

 

[93gs_t]

So it only runs rich under boost?

 

[nismoz]

Car is stock with exception of a FMIC and SAFC. CAR WAS RUNNING RICH WHEN COMPLETELY STOCK. AEM wideband says its rich, I can make it run fine with the SAFC but not with it off. Should run fine without it though it's not modded beyond FMIC.

 

[spyderdrifter]

I'm willing to bet it's one of your sensors at this point. Back when I was in school for automotive tech, I had idle surge issues that I cured with a new ECT sensor even though I thought it was absolutely pointless. I thought the ECT had no affect on idle or fuel trims, but it does, although it is an indirect way.

 

[nismoz]

Engine Coolant Temp sensor
Throttle Position Sensor
Idle Air Control sensor/ Idle Speed Control sensor

Bone stock runs, idles, starts fine only rich as boost is there. If temp sensor was bad it may stay in open loop but at WOT its open loop anyway so shouldn't it run fine under boost at WOT? At least I think it would, also did see that the temp sensor prong was corroded a bit. Cleaned it but not tested yet working with my bro-n-law on a ka-t engine build at the same time.

TPS reads through SAFC and on the scan tool so shouldn't that be good enough as verification that its working.
Idles fine wouldn't that be giveaway to a bad IAC or no?

Thx for my DSM families help BTW.

 

[spyderdrifter]

Sensors as old as these can be can be problematic at varied times. The TPS will read whatever percentage it's at, but could still be bad. Testing it is the best way to see for sure, or even if the TPS for example is functioning properly, it may not be adjusted properly. There's a thread on Vfaq.com that shows how to adjust it. It's how I adjusted mine and eliminated it as a problem.

 

[nismoz]

Shame my windows phone wont play the tps video, an been6yrs since i replaced the one on my awd tsi and dont remember the voltages.... Any help

 

[spyderdrifter]

A TPS shouldn't die in 6 years. Maybe out of adjustment, but not dead. Maybe I misunderstood you, but yeah.

 

[nismoz]

Im by no means trying to be rude, i only want to make sure for future reference to ppls questions that there isnt misleading info because about 5 times in this post or others,ppl arent reading the entire post an are mistakinly posting info not relevant to thread....

Im not working on a tsi,its been gone for 4yrs. Workin on a 98 gst, i was only stating that its been awhile since I had to set a dsm tps. An cant view the video on vfaq can someone tell me the voltages and at what percentage they should be what?thx

 

[sydkic295]

You should try replacing the o2 sensor. It could be worn out and not sending out right data anymore. how many miles do you have on the car?

 

[spyderdrifter]

I've never seen a video for it on vfaq. Here's the link I used TPS Adjustment


Miles on his car may differ from miles on his engine.

 

[nismoz]

You should try replacing the o2 sensor. It could be worn out and not sending out right data anymore. how many miles do you have on the car?

Stated earlier new bosch upstream sensor... Was my first thought.. No good that done.. An damn was the old one stuck, torch or 2 o2 sockets wouldnt get it. Ended up cuttin a good sensor down to get a impact socket on with a 16" pipe on the 1/2"drive ratchet...

Tps was good,set an still same. Beginning to think intake gasket is gone on the bottom.... Maybe?????

 

[spyderdrifter]

That'd be another possibility. Excessive air being sacked in will present a lean mixture condition which will in turn call for more fuel to compensate.

 

[nismoz]

Ok so,i have many cars an the monitors obd2 bs has kept me from drivin it over the past few mths but i drove it earlier and noticed the boost fell to 8psi. I pressure checked the intake. Finds- intake elbo leaking,4 inj orings leaking at intake and throttle plate leaking at bushings.this was at 2psi and the tp was whistling at the bushing, 8psi was a whooshhh. Maybe this is the infamous answer to this question that I've seen asked so many times on the net but never an answer. I will prob fix them tomarrow as well as clean the injs if the parts are available at 1 of the 5 local robberies.
And unlike most i will update so that the info is out there.
If anyone comes up with something not mentioned, pls post it can only help someone later on.

 

[spyderdrifter]

Nice. A few months back I was doing leak down tests on my engine and found my cyl 4 injector o-ring to be leaking. But I knew they were most likely original from the factory (since the average person won't replace them) and I bought a new set to replace all 8 O-rings/bushings. Things were fine until I ramped up the psi on the follow up leak down test. Everything sealed at 10psi, but I decided to go higher since I can get my car to 12-13psi of boost. I went to 12 and found my OEM BOV was bad. So luckily I had a spare knock off Greddy BOV that is currently under my hood performing just fine. No more leaks. Leak down tests are vital. Was a good use of your time.

 

[nismoz]

Stock bovs do lift at 13-14 psi,all of them..,
My fix for that- a shotgun magazine tube spring about 2.5" long spun around the shaft in the bov....good for up of 20psi