S70 hard starting cold or warm
 

Seems there are plenty of problems out there with hard starting. I'm all of sudden having the same problem and it appears to be getting worse. Car sits over night in my garage and I go to start it and it cranks and starts but immediately dies. I step on the gas while turning the key and it finally catches. This takes about five times before it finally starts. Once it does start I have to keep my foot on the gas pedal to keep it idling. Once the car warms up a bit it will maintain idle and run fine. This starting issues appears to be getting worse time now doing it even when warm. I recently replaced the coolant, themostat, new front O2 sensor (Bosch), cleaned the throttle body, replaced oil trap, and replaced the IAC valve with a used one. No CEL and the car appears to run fine once I get it running and drive it a few minutes. Gas in it is about a year old since it sat for some time while I was repairing it. I now have two additional IAC valves at my house since I can pull them off of salvage cars on the cheap. I'm wondering if the IAC valve could be the problem or if there is some PCV clog.

You probably have a clogged fuel filter. I would get that GAS out of that car. Sometimes that old gas gels and can clog the entire fuel system, messing up the injectors and everything else in the system.

Add some Lucas fuel treatment. It really would not be a bad idea to pull the fuel filter and hit the starter to dump the fuel out of the tank into a gas can or something. You could also connect something to the fuel rail and dump the gas out that way. Old gas could be like pumping jelly through the system.

I think changing the fuel filter is probably the next thing to do but I still think there is something going on with the IAC valve. Seems so odd that this just started happening after I changed the O2 sensor.

i would do two things, a new iac valve, and an ect (engine cooling temp sensor). then go from there. it is possible you have mulitiple issues at one time. i would look at getting a fuel pump replay too.

crush

ard to start problem SOLVED
 

Dear Volvo owners.
I had very hard time finding a logic answer for the hard tostart when cold problem
I been reading many many many posting regarding this problembut no one (( I MEAN NO ONE )) ever really came up with solid answer on how toresolve this headache.
I am not a mechanic but I analyze everything in logical wayand I think I might find a very good answer (hints) to resolve this nightmareand help others.
I bought 2001 V70xc with about 190Kmiles and it came withhard to start (specially when cold ) problem, I did the usual things , Tuneup,plugs etc, etc,
Next day same problem,, came on line and start to read,, youtube, every available resource and still no luck.
I even replaced the ignition coils and still no difference
Finally I start to go little deeper in the problem which isthe spark plugs ,, every time I rook them out they are fully covered withsoot,, not light coat but a lot.
I realize it is RICH running issue, too much gas, less airand did every possible vacuum leak test you can think of, everything is tight.now time to think more about the gas, the supply, the fuel pressure and relatedmatters. I started with the filter was unusually heavy (after I drain the gasfrom it) which indicate tons of dirt inside, then checked the fuel pressure atthe fuel rail during running engine it was 55 PSI , Next day start fresh earlymorning,, fuel pressure is ZERO when the car is cold,, turn the ignition on andthe fuel pressures remain ZERO. :(,, I even changed the antenna ring, no luckstill.
back to the wiring diagram and replaced the fuel relay underthe dash board ,, now I got about 40 PSI when the ignition is on but still hardto start,,
My last resort was the readjust the fuel pressure and theidea came from watching something related on YouTube
I purchased ((ADJUSTABLE FUEL PRESSURE REGULATOR)) fromEBAY, under $20.00 and for extra assurance I purchased in-line CHECK VALVE for$6.00 from ebay
that was the answer for my problem,,
Damn I hit it right,, after 4 months of searching and tryingdifferent things ,, OMG what a release
Please review the attached pictures and see what I did,,that might help the next V70xc with a headache (NO START ) owner:)