hello i am asking for a friend since we both are stumped on this car
1990 prelude si
b21
automatic
150,000 miles

the car runs perfect except when you come to a stop it slowly just cuts off and dies, you can turn the key off and prime the pump one time and will start right back up.

there is no CEL and the car is all stock ive tried cleaning the idle air control valve and did a full tune up. he bought the car this way guy just said it needed a tune up and problem still accures.

the next thing i may try is checking the fuel pressure. maybe fuel pump going out?

any ideas would be great thanks

 

bump

 

anyone???????????

 

can anyone help please

 

1990, OBDI, maybe no scan date for the IACV, you will have to do an AMP Clamp test with an Oscilloscope to see how each of the coils in the IACV are operating, also make damn sure the throttlebody and butterfly valve are very clean, did you clean the passage from the throttlebody to the IACV. Is the TPS set at the proper idle setting, maybe .5 volts (look it up). Do you have any vacuum leaks, probably not.

On the other hand, the EGR valve could be sticking open until the engine dies, if the engine has one, disconnect and plug the vacuum hose and see if it makes a difference. Also drop the tranny into N before coming to a stop and see if the torq convertor is staying locked up, although on a 90 model, I dont think so. Anyways, dropping the tranny out of gear also affects the IACV operation.