I'm working on an intermittent starting problem on my '93 945 turbo. It has 215k miles on it, I've had it for a few months and a few thousand miles.

Most of the time it starts and purrs fine. Perhaps idling a bit low, but the IAC responds to the AC running, so it may not be low after all.

Sometimes it needs to be cranked (~10 seconds per time) several to many times before it will start to run. When it starts to run, it kind of stumbles around, backfiring if you try to rev it. Then the problem just clears up, and off you go with it purring normally. Once running properly, the rough running does not seem to come back until it is shut off again.

It is less likely to have this problem with a warm start vs. a cold start, but it will have the problem intermittently with both.

Today it had 5 bouts of cranking with no fire, then 5 bouts where it would start to run, run badly for ~5 seconds, then just stop. (very consistent on the 5 seconds, without touching gas pedal or anything.) We gave up because we had to go, and took the other Volvo instead. This was the first day we didn't get it going in the end.

When I bought it, I went through it and did a lot of neglected maintenance. List (not all relevant) includes:
Relevant includes:
- new cap, rotor, plugs, wires (Bosch, NGK, Bougicord)
- rebuild distributor (replace oil seals)
- replace hose from oil trap to "y" fitting
- replace several other vacuum hoses in questionable condition
- Checked fuel pressure - on spec, varies in response to vacuum on FPR, no gas in FPR vacuum line.
Not necessarily relevant includes:
- replace struts/bushings in front end, shocks in rear
- timing belt
- timing belt cover (brittle and melted from prior overheat)
- 3 front oil seals
- fix multiple oil leaks
- re-seat water pump to stop water leak

Known issues:
- Air cleaner housing clips all broken. Sealing well on filter, so low priorty to fix. (Means replacing entire air filter housing.)

Car has LH-2.4 fuel injection, and this behavior does not set any trouble codes.

I've searched the archives and FAQ multiple times, but have not come up with anything that seems to match this "bad on startup, then runs ok" scenario. Most of what I found there seems to be no-starts (bad fuel pump relay), throttle body cleaning, or vacuum leaks. I'll have another go searching for vacuum leaks, but wanted to ask if anyone had any other suggestions.

Would a '93 with LH-2.4 have an additional injector or cold start valve? I don't think so, and can't find anything, but I came across some references that made me wonder. It would make sense if it had one that was activated for ~5 seconds - that would explain the 5 second run-then-stop.

Is there anything else that would be triggered for ~5 seconds on startup?

Thanks in advance for your help!

Roger

95 854T 257k miles
93 945T 215k miles
87 245 297k miles M47

PS - one upside to all my FAQ reading is I found a solution I wrote in ~1997 included, though without attribution. I think that was when it was an email list, not a web site. It's nice to be published! 8-)