Greetings all. First time poster here. I've searched and read posts for similar issues but still not sure what steps to take. At colder temps (below 40*f) on initial start up the idle is rough and takes multiple attempts to keep running. Seems and smells like overly rich combustion. Pulled plugs once and they wet. Once running it is smooth as can be and will not have any troubles restarting until cooling off overnight. I've taken throttle body apart and cleaned. ISC valve appears to be functioning. Air diverter valve is intact. Map sensor is clean but I don't know how to test it or if it has any bearing on the issue. I assume coolant temp sensor is working as temp gauge works and radiator fan operates as required. I'm thinking it's not getting enough air to go along with the extra fuel required for cold start but dunno......Any ideas or input appreciated. Thanks
Don't know your knowledge base, so here is a start. Search for & download the PARTS MANUAL & the SERVICE MANUAL for Haulster Police Vehicle Model 898487. This particular vehicle uses the F6A engine rather than the K6A yours has in it but the engine control system is the same with very minor differences. The maintenance manual quite extensively covers the EFI system as used by Suzuki and is a good little crash course of Suzuki rendering of EFI. Kind of sound like possibly the ISC valve is sticky and not compensating as per your thoughts. A certain amount of fuel is injected in the starting mode and the ISC should open to the amount necessary to create the proper A/F mix for the temperature. Is it possible that the ISC is opening enough but there may be some port blockage restricting the airflow? My 2002 always started good but immediately after firing off it would do a 'blip' and then settle to a high idle which I felt was the ISC quickly adjusting for A/F ratio needed, then would come down to normal idle as temp came up. Note that I live in the Philippines and it never gets below 70 Deg. at my location. Fred
Thanks for the response Fred. Yes I'd been studying the service manual that you recommended online and that's what had led me to think it is a lack of air during initial cold startup. I've cleaned the throttle body air passages etc. Pulled ISC valve and observed it move in and out calibrating? when key is turned on. As I'm understanding the description and schematic, the bypass air valve is a thermo wax type that opens when cold to bypasses ISC valve for cold start then closes as temp increases and ISC takes over air regulation. I pulled the air bypass valve and it appears to be intact. Heated it with a heat gun and the flapper/ diverter rotated as I would expect. So I'm stumped.....It's getting cold overnight so as a test I left air bypass valve out and plugged the opening and will try a cold start in the morning.......
Your thoughts seem to be about the same as mine. The 'blip' immediately after starting apparently is when the ISC actively takes control of the A/F. I never gave it much thought as it did it every start. I can't really offer any more as I am somewhat limited as to my knowledge base of EFI plus I no longer have it in my possession. I have steadily fought the battle of encroaching technology since the 1970s and have now dug myself into a deeper pit by purchasing a 2022 Suzuki Spresso vehicle with it's CanBus, Engine Control Computer, Body Control Computer, Digital Instrument Panel, Remote Locking, AirBags, and all the rest of the 'modern' electronics it contains. Seems to make one more dependant on the Dealers. Makes me wish I still owned my trusty 1962 Ford F100 that I drove until 2012. Fred Sorry for the mini-rant, just feels good to vent now & then.
Well leaving the air valve out made no difference for cold start. We've had some unusually warm weather lately so haven't done much experimenting but tonight should be down in the mid 30's f so I'm going to pull the ISC valve out and try a start in the morning. And haha Fred I can relate to your mini rant! I tend to lag about 20 years behind modern technology myself!
Hmmm my last reply seems to have vanished. No doubt something I messed up...! Anyway back to the story... Tried separate times to cold start with air valve and ISC valve out to allow for max air flow through throttle body. Same results, rough idle for 5-10 seconds then picked up and settled into high idle. Have also unplugged TPS and O2 sensor as a trial per Big Joe at G&R imports (great guy btw). No change there either. Still no joy...
Fugdup, did you figure out what the problem was with your cold start? I have a 02 Carry doing the same thing. Hoping to learn how to fix!
Mine is doing the same. Runs fine after it’s warmed up. Until then, I have to keep it running with the throttle. Not much, a good pump and half. It also seems to choke out a bit as I pump it then the RPMs pick up and engine runs. But if I let off it will settle into idle and then die. Once the temp gauge gets up it stays running but does still seam to lag a bit with too much throttle on takeoff and possibly in between gears. This is an 1990 carry that’s new to me. Says 48km on dash.
