1990 300E Stalls or sputters when accelarating

I just found this site, and you guys seem to be giving really sound advice. Here is one that has stumped my mechanic.. (he refuses to charge me if he can't solve the problem, but he has run out of ideas and apparently, spare
time :-))
1990 300E with 255k miles. Car runs perfect except... After the car comes up to temperature, it will sputter, and sometimes stall when accelarating (hard or soft) from a stop. Runs fine otherwise, with no problems at speed.
This next part is weird. It will ALWAYS sputter/stall when headed downhill, or turning right. It will rarely (if ever) sputter if headed up hill or turning left. Seems electrical to me, but mechanic was focused on fuel.
Seperate, but perhaps related: I live in Seattle, and we rarely get any really hot weather, but a few weeks ago, it went over 100. I stopped to get gas, and the car would not start (at all) after that. I pushed it out of the gas lane and into the shade, and waited 1.5 hours. Car started fine and ran fine all the way home. Problem never repeated itself, but the weather hasn't been over 80 since that day. I don't think the two are related, but I could be wrong. Based on some other postings, this 2nd problem may be an overheated ignition coil.
Both of these problems happened about 3 weeks after the car overheated (badly! ) due to a shot radiator. Guess I need to replace those every 250k miles whether they need it or not..!
Any thoughts about the downhill/righthand turn sputters?
Rick
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Fuel filters... change them out.
Fuel pump relay... change it out too.
Check fuel pressure. after everything is changed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I read your post a couple of times and suggest the fuel pressure is causing the problem.
The pressure is created by the electric fuel pump and modulated or regulated by a small can on the fuel rail. The can is a spring loaded valve and whose modulation comes from a vacuum connection to the intake manifold.
These fail over time. The regulator can be tested by simply disconnecting its rubber vacuum line. If fuel dribbles out the regulator is shot and is the culprit, if not, disregard everything here!
--
© 2007 T.G.Lambach. Publication in any form requires prior written
permission.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.