hard start in cold weather

mcvic66 · Post by **mcvic66** » 27 Dec 2010, 15:00

so after the cold stsrt valve was replaced it didn't change the way it was being started if anything got worse. so your saying by erasing the codes then it should return to normal operation but if the code is still there since i have not erased it nothing will change and how do you erase the codes

Post by **billofdurham** » 28 Dec 2010, 11:51

The codes must be erased when the repair has been done.

740 erasing fault codes..pdf: (38.05 KiB) Downloaded 626 times

Bill.

andys240 · Post by **andys240** » 29 Dec 2010, 21:16

mine wasnt backfiring but hard starting in cold weather (especially if it sat for more than 2 days) and i ran heet in the gas tank, next day didnt want to start, but added heet to the next tank, some gumout injector cleaner/water remover to the next tank, and iso heet to the next, after the second day with it in the system its started first time every time, even when it sat the better part of 4 days with 3-5 inches of snow on it. a lot easier then changing parts, might look into a water remover if erasing the codes doesnt work.

mcvic66 · Post by **mcvic66** » 04 Jan 2011, 21:10

i erased the codes it seems to be working a little better now but when cruising down from a high speed my car will backfire several times any knowledge on that

Post by **billofdurham** » 05 Jan 2011, 11:18

Check the radio suppression relay as this can cause back firing and low idle speed.

740 radio suppression relay.pdf: (151.81 KiB) Downloaded 465 times

Bill.

mcvic66 · Post by **mcvic66** » 07 Jan 2011, 09:51

how do you check these to see if they are bad or not

Post by **billofdurham** » 07 Jan 2011, 12:21

You can either replace it with a known good one or follow the instructions here.

Bill.

mcvic66 · Post by **mcvic66** » 14 Jan 2011, 17:16

the two places shown in the pic you provided there is nothing that looks like a relay so i am stumped on this one any other ideas where they could be or what could be wrong and the other day i cleaned out my throttle body to only find it was caked in oil and the intake was as well what could this be from and is it something i should be concerned about

mcvic66 · Post by **mcvic66** » 19 Jan 2011, 12:06

is the radio suppression relay locatedc in the coil pack and is there any reason y i am only getting 10 to 14 miles to the gallon and thats on a good day any input would be much ablidged

Post by **jimmy57** » 19 Jan 2011, 12:30

A problem that plagued the b230's is the throttle switch being out of adjustment.
The amount of fuel injected for cold start enrichment is based on the idle control system going to the proper air flow amount. The idle control system goes to a wider fixed opening when the throttle contacts are open and it dilutes the fuel and it may be too lean to start.
When the idle contacts of throttle switch are not closed the computer does not do the injector cut off on closed throttle coast and back fire in exhaust will happen for that reason.
The link rod from throttle spool to the throttle arm does contract when cold and the throttle getting dirty has effects as well as the cold affecting the throttle shaft making it twist a bit.
The adjustment procedure is to have a clean throttle and then loosen the 3mm screws holding the switch assembly. Rotate the switch back and forth and listen for the click of the idle switch closing and opening. It should be adjusted to where the throttle arm moves slightly when opened before you hear the click of the idle switch and the click occurs just before the throttle goes fully closed. Recheck the setting after tightening the screws, the switch may "crawl" when the screws are turned holding it. "Hair trigger" adjustment of throttle switch is an invitation for it to be wrongly adjusted for very cold temps.
The procedure from Volvo years back when the won't start cold issue cropped up was to use a feeler gauge between stop screw for throttle and the tab and it was adjusted properly when it clicked with 0.010 inch feeler gauge inserted and didn't click with 0.020 feeler gauge inserted. The feeler gauge method is not done throttle assembly mounted to intake, there really isn't room to do it.
To see if this is it go ut to car when it is at the cold temp when it fails to start. Raise the hood and rotate the throttle spool/linkage and see if that makes the audible "click" occur signalling the throttle switch is closed. Then reach in and operte ignition switch and see if it starts. Do not touch accel pedal before you try or you may get switch opened again.
If you can't hear the switch click in spite of your efforts that also tells you it is a problem.

hard start in cold weather

Re: hard start in cold weather