Birdstheword

for the last couple of months i have been trying to figure out the cause of a rich condition in my 88' LO3 T/A . At first i thought it was my ignition system " turned out it was not . " . Then i checked for exhaust leaks before my o2 sensor and i got nothing . Until last night i was finally able to datalog "new laptop " and from what the logs tell me , it looks like my car might be running too cold . I think its my fan switch that either its gone bad or it was mislabeled because the fan came on at 168 * . i am running this thermostat " JET-10170 " opens @ 180* and my fan switch is a HYP-4028 on @ 200* of @ 185* . both part numbers are summit part numbers , my engine is bone stock . a second opinion would be appreciated

EagleMark

Get TunerPro!

You only go to 164.6 degrees in that log, O2 started working around 140 degrees, dosen't look rich...

Birdstheword

I will post up another log with the car at a warmer temp ASAP , still I get the smell of raw gas and bad gas mileage, is tunerpro free?

Base91

iTrader: (1)

TunerPro is free but you can give the guy some money to help out. He deserves it.

EagleMark

Bad gas mileage? What was it when good? What is it now? It's winter, milage drops in winter with cold starts and long warm up's.

Smell of raw gas? That would be a gas leak. You mean you smell hydrocarbons, like rich exhaust? Put your Catalytic converter back on and you won't smell it. Your nose is a horrible AFR gauge.. your log did not look bad at all as far as the BLM, little rich but then it should be when cold.

TunerPro is free, TunerPro RT is free but asks $39 if you like it, but after you use it and realize what it is worth you will pay the $39. We all encourage that people pay so the author can keep developing software we can afford.

Ronny

iTrader: (1)

His BLM log shows very few hits? Does the datalogger have a flag for CL? I bet you are falling out of CL.
You might consider a new 180 therm. My fan goes on at 190 I recall.

Birdstheword

Pn# and brand for your fan switch? , when dataloging I noticed that my car never saw north of 170* because the fan came on, I think the dam thing went bad, should be on @ 200* and off @ 185* . BTW when I said bone stock I meant all emissions and factory stuff is on the car.

Ronny

iTrader: (1)

Sorry dont know the part #. I recall it was purchased by me 10 years ago from Hypertech. I also used the 160 Hyper thermostat but when the headers went on I swapped in a 180(NAPA) as it flipped OL on xway on a cool day.

cool weather WI I run 180-186 and hot weather I run 200 with AC on

Birdstheword

I think its gonna be the fan switch because I remember sometimes I would cold start. The car and the fan would be on, like if the switch was stuck on ground, and now this whole this.g with it coming on @ 170*

freaky

will a bad fan switch cause the car to be pig rich starting an throw a code 21 ( tps high volt )

Ronny

iTrader: (1)

I dont see how?

freaky

ok

EagleMark

But if TPS is bad and reading high volt, when should be low volt, it will add fuel because the ECM is being told the throttle is open... when closed...

You could leave the fan on all the time if you want and it won't cool the motor off if thermostat is working properly. Thermostat should start to open around the temp on thermostat and let water flow to radiator to be cooled by fan.

Now if your ECM/chip/bin is stock and calls for 180 and you changed to 170 you will never be warmed up as far as ECM is concerned, so it will add choke and your fuel milage will suffer...

xch3no2

Technically off choke, but possibly running on colder thus richer modifiers to the CTS signal.

Birdstheword

the stock thermostat was open @ 195 and the fan switch was on @ like 220 " i think , fan came on @ 170 and i stopped the data log when the temps tarted dropping from 170 to 156 , the only way i got the car to go past 170 was by driving it at WOT alot , even then it only reached 197 . i will datalog with the fan disconnected . btw im getting the forced open loop flag and a inttermitent rich flag .

Birdstheword

ok , here's a new log , this one was taken when the car was operating around 188*