850T, hard to start, then won't hold idle.....
 

Hi,
I have a '95 850T which over the past few months has been hard to start in the morning. Usually starts after cranking for about 15 sec's....
I have a new battery, but now it won't start unless I give it a pump of gas, then it fires up, but won't hold the idle (keeps dropping down and cutting out). I have been holding my foot on the gas for about 2 mins at 2000rpm and then it seems to warm up and idles fine. Sometimes in this process it seems to speed up while idling, kind of revving up on it's own...?
Then it drives perfectly, no stalling at lights, or sluggishness. For the rest of the day it usually starts up just fine too.
I tried disconnecting the MAF when it's running and it continued to run for about 30 sec then died.....could it be the MAF sensor? It looks clean inside.
I'm assuming ignition wires are not the issue since, once started it runs fine?

Any suggestions would be appreciated.
Thanks!

Could be a few things - when was the last full tune up? rotor/cap, wires, plugs. Next it could be the MAF - have your tried cleaning it with some MAF cleaner? Next is to check for vacuum leaks and the intake ductwork for any oddities. Last thing I'd check is the idle control valve (ICV) as a possible cause. Given the note it runs fine when warmed up I'd suspect the MAF as once the O2 sensors heat up they start tuning the mix...

Rotor, cap, wires, aprox 10yrs old, plugs 3yrs old.
I did clean the MAF, and it looks almost new, very clean inside.

Is there a way to check the MAF? Should I try starting it with that disconnected ?

Thanks for your help!

...and as a follow up...
Got it started this morning after all the symptoms described above (slow to turn over, then needs foot on gas to maintain idle and stop cutting out), drove 5 miles to work.
Some of the issue could be cold weather (I'm in the midwest where it was 20F this morning).

Came out half hour later, put the key in and it started up like a brand new car. Turned over immediately, idling at the correct speed etc....!
Very frustrating!

It sucks doing wires etc when its 20 out - but I'd start with the easy and replace the wires/cap/rotor and plugs just since the car is due. Next is I'd look for vacuum leaks - cracked tubes etc. I take it you don't have the check engine light on / codes showing up?

Also, if the car is due for an oil change, do that as well to help it spin up. The slow crank could also be due to the temp and an old battery.

I have two bits of advice:
1. Hook up an OBDII scanner and see what temperature the car thinks it is.
2. Contemplate how much plumbing for air is between the MAF and the spark plugs. If there is any leak anywhere in any of that, your MAF measurement will be inaccurate. Idle is that point at which the known airflow is smallest, and therefore the error from leaks presents itself as a larger problem at idle than it does above idle.

the progress, so far....
 

OK, I did replace today the wires / cap/ rotor/ and put new plugs in....
also, took off and cleaned the idle air control (ICV or is it IAC, sorry I'm not an expert in this stuff?) which was all gummed up and didn't seem to be moving when I shook it. After spraying in some IAC cleaner (lot's of brown gunk came pouring out) it was moving freely, and had clean metal inside (see before after photo).

The spark plugs were really black and sooty (see photos).

Also, one spark plug area seemed to be really dirty (the one closest to the oil cap), as if maybe the oil leaked out the top and into that compartment. Also there was some oil on the top of that area when I took the cover off to the spark plug wires.Is this a problem? Ididn't clean inside where the spark plug was as I was afraid of getting more dirt into that chamber? (see photo of the dirty one and the rest were much cleaner)

The most difficult thing of all was trying to replace the cover over the spark plug wires which I finally gave up on!! Not matter how I tried it just seemed impossible for it to squeeze back in there without removing the big (Turbo?) hose above it? Is it ok to just leave that Volvo cover off? Or any tips on how to get it back in place?

So, how's the car running after all this.....seems to be better, definitely the idle is "normal" when starting, you don't have to rev it for a few minutes. I'll see how it goes for the next few days, how well it starts etc and report back.

A BIG thank you to everyone for their advice!! I really appreciate it.
I don't know much about cars so this was a big project for me and saved me a lot of money!

Temp sensor.

Thanks rspi,
I'll look into this also if needed.

closing note - to get the spark plug cover back on you need to play with the wiring clips to get the wires in the right order where they lie flat and where the clip can slot into the edge of the cover. I usually wind up lining up the clips first by eye before trying to place the cover back on.

Final follow up....
 

Just to let anyone interested know, after about 2 weeks, the car starts immediately, and idles perfectly. Even after sitting for 2 or 3 days, starts right up.
The problem was definitely the clogged idle air control valve, but I'm sure the new wires and plugs helped as well (they were probably stressed from the clogged IAC valve anyway).
Thanks again for all the advice.

Alan.

I just cleaned mine thoroughly. I wasn't having any problems, but while I was there I thought I should. I was mainly replacing the brake booster vacuum hose. It was pretty dirty from what came out.