Hey again BB.

I've been working on my "rescue" 1991 244 for a few months now, slowly doing little improvements. It's come a long way from where it was when I bought it (about to be seized and auctioned by the city) and has been working generally brilliantly. It's been a real pleasure to wrench on a 240 again, I had almost forgotten how much I love these cars and their little quirks. Particularly when you have a backup car they're a lot of fun to tinker with.

Generally my 240 starts on the first turn of the starter, like ~1 sec on position three, especially when cold. But sometimes, maybe 1 in 5 times when I've gotten it up to temp and park it for a while, say an hour or so, it takes a long time to start. Maybe I'll hold it for three or four seconds before it catches, otherwise I'll let go of the key and sometimes it stumbles a little and then starts, if not I'll just barely bump the starter again and it starts.

To be clear, it never fails to start, but sometimes it requires more cranking than I'd like. Like I said it's occasional and only happens when the car is both fully warmed up and was parked for a while. I can leave the car parked for a week or more and go in to start it and it takes very little crank time to start it in that case, so I think it must be something heat related.

It has a new aftermarket CPS on it but it did the same thing with the Bougicord one I got it with, I did that just as a precautionary measure. Anyone run into this before? It may just be that it's an old car with around a quarter million miles on it and I can definitely live with it as it's not my DD, but it's weird and I was wondering if anyone knew what is happening.

The parts responsible for permitting warm starts are the fuel pressure regulator and the fuel pump outlet check valve. The specific function of both keep pressure in the fuel rail well above the vapor point by keeping the fuel from returning to the tank after the pumps are shut off.

Without a pressure test (should hold for 20 minutes at least 15 psi) swapping in new parts has a chance of fixing it. Can't tell you which first. My experience is with the fuel pump check valve having a rusty spring, but those experiences date from long ago when the cars were new to me and came from previous owners with poor fuel habits and before 10% ethanol.

Beyond vapor lock, the hard warm starts are often blamed on electrical parts taking a heat soak, but no evidence proving it is written in the forums -- just a lot of suspect CPS and power stage replacements.
--
Art Benstein near Baltimore

King Ozymandias of Assyria was running low on cash after years of war with the Hittites. His last great possession was the Star of the Euphrates, the most valuable diamond in the ancient world. Desperate, he went to Croesus, the pawnbroker, to ask for a loan.

Croesus said, "I'll give you 100,000 dinars for it".

"But I paid a million dinars for it," the King protested. "Don't you know who I am? I am the king!"

Croesus replied, "When you wish to pawn a Star, makes no difference who you are."

Not certain the order, as it is a paradox to me:
- Check OBD codes (sockets 2 fuel and 6 ignition, repeat until no new fault code
- Fuses (corrosion in front and rear)
- Fuel injection relay (cranked colder welds or replace)
- Timing belt (unlikely, unless old or tension not regularly set to skip a gear tooth)
- Fuel delivery (fuel rail pressure regulator, other cause)

You'll read here on this board some replacement crank position sensors have been faulty. So, check codes.

If you reside in a humid, or AmeriKan rust belt salt and snow hell hole (Like St. Louis, MO), or near the seaside, consider wireline corrosion of the engine control wire harness and all connectors there in. Check sensor and devices (the OBD does not sensor the condition of the ignition power stage next to the battery).

Also, you do know of the issue with the thermostat-controlled preheat diverter flap inside the air filter box. Fails to hot, always. Will fry an AMM, and faster in the hot-hotter-hottest summ-summ-summertime. There is a silver hose, usually, between the air filter box bottom and the exhaust manifold heat shield. As your state or nation auto emission requirements mandate, replace the flap valve thermostat, remove or block the preheat hose, or, well, do something to halt hot air from the exhaust manifold preheater plate to the AMM.

Do you have EGR? Clean the flame trap?

The OBD may report on on a failed AMM or, with your trusty, yet not some crappy Harbor Freight, digital multimeter, use the many times oft-mentioned method to test the AMM.

And from the FAQ (clicks FAQ above) please review:
- https://www.brickboard.com/FAQ/700-900/EnginePerformanceSymptoms.htm
- https://www.brickboard.com/FAQ/700-900/EngineOBDCodes.htm
(LJ-Jetronic 2.4/3.1 and we all know EZK ignition 116k)
- https://www.brickboard.com/FAQ/700-900/EngineSensors.htm
- https://www.brickboard.com/FAQ/700-900/EngineFuelinjection.htm

I'm probably all wrong. So, here's a start to the conversation in reply to your post with those that can actually help you.

Bentley Volvo 240 service manual or other service manual?

Here comes link-boy, copying and pasting my way to familial and genetic oblivion; MK Ultra courtesy.
- https://www.brickboard.com/FAQ/700-900/
- http://www.k-jet.org/documents/greenbooks/200-series/
- http://www.volvowiringdiagrams.com/?dir=volvo/240%20Wiring%20Diagrams
- http://www.volvowiringdiagrams.com/?sort_by=size&sort_as=desc&dir=volvo/LH%202.4/
- www.cleanflametrap.com (an index or table of contents would help us all as the page you see does not link to all articles Art has up.)

Questions? Hope that helps you.

Misses WA-state Apple Cider, cheering on the Seahawks, and Hhhhut Not. Hates the AmeriKa Midwest Summ-Summ-Summertime (Weather) and Pollution
--
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