Hey gus I've been noticing a drop in MPGs ever since I installed my Thermoblok IM/TB spacers ,cleaned my IM and TB and seafoam... I used to pull about 160 to half a tank 260ish to the full and now i'm getting about 125 to the half tank and 235-240 to the full.

I retorqued all of the bolts a week after I installed the spacers and still no change in MPG.

I let the car shift at 2500 rpm and sometimes at 3000 (but rarely)..

I do hear my purge valve solenoid making a lot of noise lately and idk if that's causing the problem or not...

I do have a CEL on for my Torque Converter, but I've always had that light on since I bought the car and the car still pulled about 260 miles until the gas light came on, so I don't think that is the culprit.. Currently, I'm pulling about 230-240 until the light comes on

 

soooo if the torque convertor is having a major issue and not locking up right
the trans is not operating correctly
your gas consumption would go up

the low numbers you report pre spacer indicate something is wrong overall
You have verified every gasket and bolt on the install is good???
no vac leaks???
No broken motor mounts??
I expect 300+ mixed driving before the low light in my 01
half tank isnt accurate--heat can affect reading of guage or sendor could be wrong~
go off miles driven to gas used in that time

there may still be a problem of: needs 2nd seafoam treatment for noobs to product /first time car has been done
--2nd time gets better cleaning.. now that you have an understanding of warm up drive, install- wait- blowout drive

Use of 1 can thru gas tank- to half tank of gas, is suggested for max effect for injector system
Home Depot has seafoam for 5 bucks!!! who woulda thunk!!!

How old are your spark plugs--running the correct NGK iridium, iridium ix or the stock ngk platinum
8 bucks each, not 2 bucks-those cheap plugs are not for the TL~~ I dont care what the parts counter guy said `the book says`

 

Yes every gasket is good and I have no vaccum leaks at all.

And yes, my torque converter is not locking up when i'm in 5th at highway speeds. That might be an issue too. I plan on getting the trans rebuilt in about a month or so.

When I did seafoam, I did 2/3 in my gas tank and 1/3 in my vac port. Do I need to do more? Should I have done 1/2 in my vac port and a whole can in my gas? I might do seafoam again just for the hell of it since the car wasn't maintainted too well by the previous owner besides oil changes.

And Yes I am running the correct NGK Irridiums. I made a thread about spark plugs a month ago and I had the wrong ones in there.

Hopefully fixing the transmission will fix the problems.

 

seafoam says to do 2 treatments the cars first time, then good for a year when you will do one treatment

2 ounces per gal of gas is max dose- cleaning strength..1 can to just under half tank works well --giving it time and heat cycles to get all the parts clean

vac port at TB--not some sideline that doesnt feed all 6 cylinders-
1/2 can or so is good there..as desired~
Also go thru the TB throat opening to get both sides and edges of the air plate

make deep creep from seafoam,, with a small spray bottle for that job

 

when you cleaned the intake manifold --you went all the way thru the manifold egr passage with a wire rod?
Lubed the egr valves arm?
cleaned the TB,, bottem part- accessed the IACV to clean?

beyond that-- its your trans screwing up the mpg

 

Yup I cleaned every single part of the TB and IM. Also went through with a metal hanger to clean the EGR. I did not lube the EGR valve arms because I never got an EGR code, but I thought it just needed a cleaning. Took me forever because there was so much gunk in there.

 

3 cans carb cleaner seem to be the trick to cleaning egr passage and ports
The actual valve, you lube the arm with spray lube
and make sure to poke the ports under it,,leading to the main passage

code only happens if the system is totally clogged

 

Yeah I used a lot of carb cleaner and a steam cleaner at my shop. I poked all those little ports in the IM too. They were all clogged up.

Well I'm at 200 Miles and sitting at 3/4 of a tank.We will see how my mileage is in the next 2-3 days

 

I'm still getting the code and I cleaned the ports this past weekend. I reset it and it came back about 75 miles later.

It was dirty, but not clogged. I wonder if the EGR valve could be bad.

Also, how does the car measure EGR Flow? Reason I asked is I had a ford that the monitoring sensor went bad, not the egr.

 

In addition to the manifold cleaning,,did you do the lower section on the engine block thats part of the egr ?/
there is usually lots of crud in there too,,use shop vac to remove as its poked loose

Might have dislodged some crud thats now getting stuck and interfering with flow rate?
Hate to say it but: take it back apart and recheck all your work-

if the egr valve arm moves freely its working (smog part guru's correct me if needed)
thats why I mention lube it and exercise arm to assure operation

 

WEll MPGs went back to normal. Around 260-270 before the light comes on. Going to work on the tranny this month...

 

all by itself its better?