Help! My 1990 740 Wagon (nonturbo, Bendix Regina fuel injection) has on-again-off-again fuel injection/ignition problems. I tried to diagnose the problem myself, but to no avail, so I took it to my mechanic (actually had it towed, because it wouldn't start). The first mechanic got it started, but couldn't fix the problem entirely. He isn't really a "Volvo specialist", he mostly works on VWs, so I took it to a second mechanic who specializes in Volvos. The second mechanic also had trouble figuring it out. Unfortunately, I'm not sure exactly what the 1st mechanic did to get it started, but all the second mechanic did was to restrain the primary ignition wire so it wouldn't come in contact with the secondary ignition wire (?). Note, I was able to drive it to the second mechanic. He thought this would do the job, but I stalled in traffic last night, and I had trouble restarting it (not a good situation to be in!). Anyway, here is a list of the symptoms:

- When idling in stop and go traffic, it will idle rough- the RPMs will cycle between 600 and 1000 with a 1-2 sec period. It doesn't so much miss on a cylinder, but cycles up and down (?) This has decreased since going to the 1st mechanic. Actually, I haven't experienced it since.

-Also, when idling in stop-and-go traffic for any length of time (10-15 minutes), It will get an intermittent surge for just a second. This has continued, even after taking it to the mechanics.

-Sometimes, after idling in stop and go traffic for 10-15 min, when I finally get up to hi-way speed, it will get what feels like an intermittent miss. This lasts only a few seconds (approx. 5 sec).

- Prior to going to the 1st mechanic, the rough idle and the miss at speed seemed to be less common after running some fuel injection cleaner through the system. Also it seemed if I used Chevron gas (with Techron), the rough idling was less frequent.

- When I've checked the diagnostic computer, I have gotten an Idle Air Control Valve fault code - some times. But, when I've checked the idle air control valve manually, it worked properly. Both mechanics seemed to think this component was ok (could we all be wrong?)

- By far the worst symptom (and most dangerous), is it can suddenly stall after I've been idling in traffic for a period of time. It won't restart immediately, and I have to wait 30 to 60 sec, then it will restart (?). The people behind me don't seem to appreciate this.

- On two occasions, after sitting overnight (overnight low in the mid 30s) it didn't want to start. I pulled a plug, and it had good spark. But, even after cranking the motor over for a good 30 sec, the plugs were bone dry.

Any insight into my problem would be appreciated.