I know that there have been a lot of threads here about stalling, and it seems like there can be any number of reasons. I am not a DIY'er in this area, but need some advise to assist my mechanic.....seems they aren't sure what the problem is either....more on that later. (Sorry if this is too much detail)

Symptom: Warm car (at least driven for 10 miles at 55mph when this happens...so no longer "cold"). Driving 55-60mph, then fairly hard break to turn quick left. Near end of deceleration, car starts shaking pretty wildly as stall begins. At the end of the deceleration...now only going about 5mph, car stalls.

First time this happened last week, car would re-crank and seemed to idle fine even once put in gear, but as soon as accellerator pressed, car stalls again. Didn't trust it...so towed it in to shop. They ran diagnostics on car. Said it was "ignition circuit"...and basically replaced several plug wires and plugs. Adjusted fuel injector. Ran fine for a week.

Week later, happened second time, on exact same place on road during exact same maneuver. This time, let car sit for just a few seconds, re-crank fine, idle fine, let it idle for about a minute, put in gear, and was fine. This time, drove it to the shop later in day.

Shop ran diagnostics again, but couldn't find anything at all wrong. Now I am nervous that I'll get stranded. One question I have it that they told me that since it was a 1992, that there isn't too much info that they can get from actual diagnostics (at least not like a 1998 or newer). So, at this point if they can't recreate the problem, they don't want to just guess and start replacing things. The tech took the car home tonight, and will attempt to recreate the scenario that I told. Somehow I think the odds are against him since I didn't have a problem for a week in between incidents.

From this site, I see that there are several possibilities for this generic symptom. But, what is the most probable?
Fuel pump, fuel pump relay, OVP....


Any educated guesses would be appreciated. If I have to start replacing things I would hope to start with the most probable....or it could add up $$$ quick.

Thanks.

Stalls on hard deceleration are almost always the idle control valve. This will be worse since by now the idle control valve hoses are rock hard and probably leaking.

I would clean the idle control valve and replace the hoses if not pliable (they won't be), and check for and repair any other vacuum leaks found.

If that doesn't cure the problem, it's time to look at the fuel system -- bad injectors will drive you nuts, so will an out of adjustment mixture (although this will probably be cured by fixing the vac leaks you surely have).

A bad OVP can cause this, as can a bad fuel pump relay. Both will cause problems while driving, though -- if the car intermittantly stalls while driving, as opposed to stoping hard, replace the fuel pump relay. If the OVP has a single fuse on it, replace that too, it's about time. You should also have the fuel pump current draw checked, as a bad fuel pump will damage the new fuel pump relay.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

I've heard of this from different shops but never experienced it but as I was told it always turned out the fuel pump was the culprit.

If it is the idle control valve....what can I expect short term? Will it drive fine, just have potential problems when decreasing speed quickly? Or, will it eventually get worse so that it will not idle even after initial start?

The Fuel Pump Relay is in the MAS on my 92 300E with same issues. Is there a way to check the MAS, or are there codes that may be set and how can one get to read codes without taking to mechanic.

Have replaced rotor, cap , OVP Relay, plugs and checked hosed for leakage. Had to replace right side hose on Idle Control Valve. Still stumbles, just would like to know if MAS can fix this issue.

Sorry, found that I never posted the resolution to my issue here. After getting several suggestions, I had found another story (on another site) where user had exact same problem. Ends us simpler, and cheaper than thought. Again, symptoms seem to be that the car had to actually sit for a few days to make this happen, which is why it only happened on 3 successive Mondays. In other users case, was found to be the distributor. I talked to my mechanic, who did NOT believe that to be the issue. But agreed it had very slight chance to be the problem, and agree to change it since it was a cheap repair and probably needed to be done anyway due to age (was about $100-150 I think). Since replacement, have not had another single issue...at least not like this one. Seems that it was the distributor after all, and not idle control valve or fuel pump relay. Hope this info helps someone else...