Just picked up another 400. This one a 93 w/ 135,000 miles. All services don at 120,000 miles.
I'm experiencing the hesitation around 1100-1500 rpm like my other. I had my machanic look it over, and he said he gets a DTC 31 . We tried a used Volume Air Flow Meter, but no haps. He told me if a new Volume Air Flow Meter doesn't solve the problem the problem is the ECM. He gave me a printout w/ the circuit desrciption, diagnostic chart, and inspection procedures.

My question is if I spend the cash to get a new Volume Air Flow Meter and it doesn't cure the problem, how much is a new ECM? Or better yet, can I upgrade to an aftermarket stand alone system?

Thanks

Mousiee

 

What type of "400" ?
Get a second opinion. Sometimes different eyes result in a different analysis. Used parts are sometimes expected to fail.

 

i would have the mechanic check the EGR valve.

 

Sorry for the delay in response. I have a 95 SC400.
I took it to another mechanic and he insist nothing is wrong with it. He said it may be the spark plug wires, but they were done last year.

 

I'll ask them to check that out when I take it back.

They left a old Air Flow Meter under my hood. I installed it and reset the ecu. When I started the car up the check engine light came right on when the rpms dropped. Then I re-installed the one that was in there and reset the ecu; no check engine light. The car ran great for a while then the hesitation came back.


The DTC no. from the printout the mechanic gve me is 31 and the Diagnostic Trouble Code Detecting Condition says:
All conditions below are detected.
(a) No volume air flow meter signal to ECM for 2 sec. when engine speed is above 300 rpm.
(b) engine stall