I have had neglected my Coolant for too long... My Radiator had developed a very very small leak... so small that I could only see about a drop of coolant.. and once warmed up it was invisible if it wasnt by for the residue left over after the coolant evaporated.

So I flushed the coolant and pumped it up with water and Prestone Radiator flush ... the prestone that requires you to drive the car for 3 hrs before dumping it... well it didnt do much... the residue inside the radiator was not even affected... so I flushed it again!!! and something... something opened up inside the rad cause this time around a whole bunch of liquid came out... I said about two gallons.. as apposed to about one gallon the previous times...


Here is the kicker... I was scanning the PCM before during and after the flush times...

No change in Idle quality nor vacum... before and after... but what really caught my eyes was the fact that before the Radiator flush my injector pulse were around 3.1 and 3.2 milliseconds and after the sendond rad flush... Now I am getting between 2.5 and 2.6 milliseconds... steady. The Timing advance is now a very steady 20 degrees... before it was fluctuating down to 17 and sometimes up to 21 degrees.. also the long term fuel trims have moved up from a 112 back up to 119 and I saw them up to 126 right before I parked her yesterday afternoon. meaning the PCM is not pulling that much fuel anymore... not runing so rich I guess...

The Air intake was at roughly 8grms now it dropped down to in between 6 and seven grms mostly 6grms... I even saw it down to 5grms for a couple of seconds... I will have to take a few logs just to make sure its not some vacum leak somewhere.


The in dash temp sensor is more more acuratelly matched to the PCM temp sensor reading.... meaning... before the rad flush the in board temp meter would goo all the way up to the red line and the pcm was reporting 210* degrees... right now the PCM will report about 227* and the inboard dash meter will be still shy of the redline.


In conclusion: Flushing the system twice appear as helping to reduce the fuel needed to keep a decent vacum and idle. I think this is due to deposits thay may have been keeping the sensors from reporting the right engine temp.
I have driven the car just once and I did one pull to 65mph and it was very very smooth pull.... I will need to do it again on a hot day and log it... cause it may be just a figment of my imagination... and I rather have hard data.


Oh I am using the regular Green stuff together with Blue Ice..... I fix the rad leak too.

I wanted to share this info... for those people who have fuel problems... I will keep the scanner on today again and see if there are any further changes.


Have all a nice day.

Marvin

--Edit... My fan comes on at 227* and goes off at about 215* .. all the testing was done parked at idle exept for the one time I drove and back from work. PCM has never been reprogramed.

 

Just an update... car runing good. Did a smooth pull to 75 without a glitch.

is basically using less fuel by looking at the reduced Injector times... steady now at 2.7 ms at idle.

The coolant temp sensor and the in-dash meter are even more closely aligned.... For those guys who have the fan not coming on till it hits the redline... it may very well be just a case of clogged/dirty coolant system. Superficially it appears as if my fan comes on earlier but its the same temp reported by the PCM.... the in-dash meter its showing a lower temp.. thats all.


Marvin