Already did a search and saw a variety of answers. Need some advice.

Hard Starting when cold soaked (it's been between low 20F and 32F here in the morning. Cranks a long time, then it tries to catch. Crank again for a long time and then it fires. Rough at idle and some stumbling until the engine temp needle starts to move.

I'm 99.99999% sure there is no cold start injector and based on some searched posts, the computer keeps the injectors open longer during cold start. So the possibilities so far are:

- IAC sticky (will pull and check freedom of movement and clean if necessary)
- Temp sensor bad (will check resistance at the sensor using the numbers from Bentley's manual)
- Wiring from temp sensor to computer bad (same test as above)

Any other thoughts on items I should be checking?

Results of this morning's investigation:

- Coil. OK
- Coil wire. OK
- 12V to coil. OK
- Spark plug wires. Not okay. 3 had no resistance what so ever. Suspecting a broken connection between the wire and the spark plug boot I put a dental pick down the spark plug boot opening and touched the end of the wire. That checked out ok. So i had three broken wires #1, #2 and #4. Bougicord wires. Second set in 2.5 years with the same issue. I don't want to condemn this brand. I'm careful to only lift the wires off the spark plug using the boot, not the wire. Maybe my technique is bad. I guess it's possible for the boot to stick to the plug (or spark plug electrical connection), I pull the end of the boot, which is stuck to the wire and "snap" the connection breaks? Helpful thoughts are welcome.

Fortunately, I've got a collection of "old" spares that I could make a complete set from. Started right up.

Lucid is right on the money about air leaks causing rough starts and idle issues. There are lots of places you can get air leaks, from holes in the bottom side of the air intake hose (oily air intake hose) to things like the hose going to the flame trap splitting or coming loose, or any one of the vacuum lines being cracked or split.

Every time I have gotten a hitch or shake in the idle (large or small), replacing air and vacuum hoses has been the fix.

I would go with the overkill method. Pull of the large intake hose, check for holes, clean the oil and gunk out of it. Pull the flame trap off the breather box and check the hoses and check for cracks, leaks, and a if you have one for a mushy adapter where it connects to the breather box. Your model already has the relocated flame trap I believe. Clean the flame trap just because you have it out. Clean the hose and lube the IAC motor with a good light turbine oil. Remove the throttle body and give it a good cleaning, install new gaskets.

Check every vacuum line that goes to the vapor recovery system, the cruise control if you have one, the interior vents, and any other connections. If in doubt, change them out was my approach.

There is a pretty easy test for a bad IAC by the way, you do it with your foot. Before you start the car, hold the accelerator down enough to disengage the switch on the throttle body. An open throttle body takes the IAC out of the loop. If it starts and purrs like a kitten with the petal held in, your IAC might be suspect. Does not mean you should not go ahead and clean the hoses and lube the little motor. A sticky IAC will make it idle like heck.

Good Luck,

Paul

Look for intake air leaks after the AMM, making the mixture leaner than the ECU thinks it is for that cold temp. Once the engine warms a little, the ECU-O2 sensor can compensate to some degree, masking the "false air" roughness.
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Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

You make some great points. Looks like I've got a place to start this weekend looking for vac leaks. Any suggestions on how best to find airleaks in those accordian hoses going in and out of the AMM?

S,
J.R.

"Any suggestions on how best to find airleaks in those accordian hoses going in and out of the AMM?"

Don't sweat the one going INTO the AMM, except for loosening it as needed. As Paul and Philvo point out, it's the "downstream" one that develops leaks where it rubs on the inner fender. Remove it for a close visual inspection.

Other possibilities for "false air" (air not sensed by AMM) include any vacuum hoses, the intake manifold gasket, injector seals, etc. A search on vacuum leaks should turn up several methods for testing if nothing is found visually. Below is a canned post on a method I've used in the past.

===========>
I use Propane to test for vacuum leaks. It's less messy and no more volatile than carb cleaner or other sprays. Take the nozzle tip off a propane torch and replace it with some snug fitting rubber hose about 2 feet long. Practice with the valve to get a moderate gas flow (not a roaring blast).

With the engine at a warm idle, open the gas valve and poke the end of the hose around each injector for a couple of seconds. If the seals leak, you should hear an RPM change when the propane gets sucked in and burned**.

Do the same around any other suspected areas, like hidden vacuum hose ends and don't forget the intake manifold gasket itself.

To block the breeze from the fan, lay a piece of cardboard from the fan shroud to the engine

**If you use a Digital Volt Meter to "read" the O2 sensor output voltage (O2 signal wire disconnected from ECU, you'll see the signal voltage rise instantly if any propane gets drawn in.
<===============
--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Pulled the following:

- Hose from AMM to intake (no issues)
- IAC. Very little gunk. good freedom of movement. cleaned it anyway
- Throttle body. fair amount of gunk. Cleaned it out and installed new gasket
- checked vacuum line connections and lines. No issues
- cleaned and reseated electrical connections at AMM, IAC and throttle body
- pulled fuze 6 to reset the brain

I have not tried the propane trick, but that is next, unless someone chimes in with another idea, and I'm looking for them right now, it maybe time for my local Volvo independent.

Tried starting it and same symptoms. takes about 10 seconds of continuous cranking before you detect a spark, continue cranking and it all starts to catch. When it does, there is a hefty cloud of "smoke" at the exhaust. I suspect it is because the injectors keep doing their job even if there is not a light off of the engine. So there is a pretty hefty rich mixture burn off. Idle it at 2000 rpm for about 30 seconds and everything is okay.

Thoughts?

S,
J.R.

That suggests it's getting fuel, which means the ignition is "working", but how well? Do you have a history on cap, rotor, wires and plugs? How about pulling a plug after cranking (but before it runs much, if any). If it looks or smells gassy, the spark may not be good.

Try reseating the coil primary connectors as well as at both ends of the high tension wire.

Also try spraying the distributor cap and wires with WD40. It can temporarily cure bad wires that are leaking off the high voltage if damp.

--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Bruce,

Thanks for the thoughts. I had in fact reseated the primary coil connections, but I have not begun to trace the ignition yet. I did a major tune-up about 50k miles ago (30 months ago) and installed new plugs about 5-8k miles ago. Coil has never been replaced and the car has about 160k on it.

I saw this one other time on my 1981 Volvo. When the coil started to go bad it took longer and longer to start until it never started. It was finally traced to the coil. Curious thing was it would show some spark at a plug and at the coil wire when grounded, but it wasn't a bright arceee spark as I recall and it also tested okay across the terminals. I've got some more work to do tomorrow.

S,
J.R.

Would most likely look something like this:



Regards.

Paul

it often chafes from undeneath, you need to take it off and visually inspect the bottom. I have been able to "gorilla tape" the bellow until I got a replacement.
Philvo
'93 245 alive and well at 305k.