Odd Cold Start issue

COS850Turbo · Post by **COS850Turbo** » 31 Dec 2019, 11:49

It is cold here in Colorado. Like in the low 20's to 40's during the day and even colder at night. My car will crank and try to fire a couple of times but will not start. If I keep cranking and hold my foot to the floor it will eventually catch but does not rev up or high idle. It just goes to a smooth steady idle at about 700 RPM ish. Once it starts the first time I can immediately shut it off and it will start just fine after that with no extended crank. It still does not rev or high idle but it does start and low idle just fine. The car runs and drives just fine with no other issues and no CEL lights.

I have jumped the Fuel Pump Relay to test that with no change so I don't think it's the relay. I have also changed out the coolant temp sensor under the thermostat with one from the junk yard. Can't say the temp sensor is 100% working but the odds of 2 bad ones? I'm not sure where to go from here or what else could cause these kind of issues. What do you guys think?

COS850Turbo · Post by **COS850Turbo** » 31 Dec 2019, 11:51

Sorry you likely want some details on the car. It's a 94 850 Turbo Sedan. Pretty much stock. I currently trying to get it to stage 0. It has 126K miles on it.

Post by **SonicAdventure** » 31 Dec 2019, 13:32

Hi,

I also have been having cold start issues with a non-turbo 96 850. I think mine is also the fuel pump relay which I plan to swap out next time it acts up. As long as the ambient temp is 35 F or higher it gives no issues. Distinct clicking/whirring sound from fuel pump relay when it does finally start up. I also suspected the ECT sensor and replaced that but it made no difference.

Since you seem fairly confident its not the fuel pump relay (or the fuel pump?), how is your cap, rotor, wires, plugs? I was having lots of stumbling and stalling issues this summer and after a good tune up using all OEM parts I haven't had any issues. PO had incorrect and incorrectly gapped (but OEM Volvo!) plugs in the car, the cap was fouled, the rotor was shot and the wires were junk. If you go this route, only use OEM parts and Bougicord wires. They are not that much more than generic brand and are just the go-to brand for this series.

Good luck!

Post by **abscate** » 31 Dec 2019, 14:56

The Volvo version of the cilice is the KAE fuel pump relay, which will soon have you chasing your tail with another round of fuel delivery problems, long after the Siren Song of its’ low price is forgotten.

COS850Turbo · Post by **COS850Turbo** » 31 Dec 2019, 15:13

I have replaced the plugs with new ones not 30 miles ago. I have not done the cap, rotor, or wires yet but they looked OK. I think the proper test to take the fuel pump relay out of the question is to put a jumper wire in pins 15 and 87 and that bypasses the whole relay and runs the fuel pump. If the relay is bad then this should fix the issue. Right? I also have 2 spare relays that I took out of the junk yard and I have also put all of them in as well and have not seen any change in the issue. Once it starts it runs great. Normal boost, plenty of power, no stumbles or sputtering at any throttle position, and a silky smooth idle. I'm not sure what to test from here? IAC maybe?

Post by **misha** » 31 Dec 2019, 18:12

Ect,fpr,weak fuel pump or clogged fuel filter.
There is nothing else left.
What you can do is to check fuel pressure at fuel rail on cold engine.

Post by **erikv11** » 31 Dec 2019, 18:16

You have it right about the relay. Go ahead and jumper it to be sure but I agree with your original posts that it sounds like you have already covered that with your junkyard relays.

I also agree swapping in the junkyard ECT pretty much rules that out. Unless the problem is the wiring in the ECT connector is frayed.

No good ideas where to go next ... cleaning the IAC never hurts though. Could also clean the throttle body for that matter, but again no good logic to connect that to the issue. Misha would be onto something with the FPR though.