1993 Bonneville stalling while driving

[M2116x6]

My father's 1993 Bonny has been stalling at random while driving. No particular pattern to it. It's not giving any error codes. Usually restarts in a couple of minutes. The mileage is 160,000. Otherwise it runs great and has been maintained well. Stalling in traffic is not a good situation.

What should we be looking for with no codes? The fuel filter has recently been replaced.

[maxwedge]

Forget codes, check for spark and /or injector pulse, if none the crank sensor is the usual culprit this assumes fuel pressure naturally.

[dontbesosure]

Check fuel pressure under a variety of conditions. Start with turning on the ignition for the initial priming of the pump, note the peak pressure, leave it on for a few minutes and watch to see if the pressure drops by itself and how much it drops. Then check it again while idling.

Now, if all this checks out and you're seeing good numbers, you'll want to swap the ICM and coils if possible. Not hard or expensive to grab a set from a local yard.

If its a sensor failure like cam or crank, you'd be getting a code by now.

One other thing..that sometimes won't throw a code..is the MAF....usually you'll get a code 34 right after a heavy stutter or stall, but it can't hurt to rule it out. Take a trip to your local parts store and grab a can of MAF sensor cleaner... Take out the screws on the maf sensor (the flat black sensor on the front of the throttle body, pull it out, and spray the sensor elements with the spray and throw it back in there. Usually cleaning this will get you better mileage and throttle reponse, so doing it now would help in your diagnostic efforts.

This covers your air intake, fuel intake, and ignition...if its not one of these...it'd be very surprising.

[Jrs3800]

On every 3800 made its possible to have the Crank sensor failure without any codes.. I have seen and dealt with this time and time again..

Maxwedge I completely agree with you bud

[big white bufflo]

simptom of crank sensor is an occasional buck like eng shut off then runs fine while driveing ,no start , will throw code 43 ,42 but most of the time the code gets erased after restarte it a hard one to pin point but most likely proublem

[Jrs3800]

IIRC off the top of my head.. Code 18 would be the cam / crank error.. 41 would be loss of cam sensor pulse( loss of signal )..

Again.. Its very rare to actually get a Crank error code even when the Crank sensor is failing..

42 - Electronic Spark Timing Circuit
43 - Electronic Spark Control Circuit

[scooter72908]

I've a 93 Bonneville and thought I had enough fuel pressure but when I took it in to the Pontiac Dealer and they found that the fuel filter in the gas tank which is connected to the fuel pump had collapsed and was restricting fuel flow. they of course replaced the pump and filter and is working fine.