I have an interesting problem with my 89 that I cannot seem to nail down. The code produced is 44 which indicates a lean exhaust condition.

Symptom: In the AM 70 degree been in the garage all night, starts right up can drive to work - 5 or so miles no problems whatever. No code

Park it, do not drive it all day sits in the sun 90 ish day can be humid or not, start it up it sputters like mad have to jam the gas pedal, etc stagger home code 44.

It does not do it all the time, sometimes I go weeks and it does not do it at all but the above is the only pattern I can find. Tried higher octane gas, changed plugs, replaced exhaust header gaskets (headman) checked for any exhaust leaks, replaced tps, all sensors seem to check out.

edit: TPI 305 all stock

Has anyone run into this before?

 

im just stabbing in the dark here but have you checked your MAF?

youve got a burn off relay with it and if i remember correctly my friends 89 gta had a similar issue, swapped 3 MAFs and it was his relay

 

no I have not checked that yet. When I purchased the car last year the previous owner had recently 12-18 month installed a new MAF, fuel tank and pump and had all new gaskets done on the top end.. So ruled those out just due to age of other parts.. But I will give it a shot... thanks for the suggestion

 

Well I don't know if it fixed it or not, but I ran a can of seafoam through the engine and gas tank, and some crc maf cleaner... So far no problem 3 weeks, the only difference is we have not had a humid day but so far so good.. guess maintenance is key....