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98 S70, N/A Long crank... engine Temperature Switch related?

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

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theWIFES_S70
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theWIFES_S70

98 S70, N/A Long crank... engine Temperature Switch related?

Post by theWIFES_S70 » Tue May 10, 2016 11:52 am

Hey everyone,
Just wanted to get some feedback. I installed an FAE Coolant Fan Temperature Switch (https://www.fcpeuro.com/products/volvo- ... -9186486-1). Earlier in the Spring when I got the P0116 and P0117s and the car wouldn't start... I know, I know, always go OEM... Well, at the time, I was having a crisis of faith and was hoping I could get some goodness out of the FAE one...

Today, I noticed a really long crank to start the car. Could this be related to this sensor? Even on a cold car? I read the post on here a week ago about a warm engine start problem. (In which case, the non-OEM ECT would make sense...) Before the Fuel Pump and relay both went out, the car used to crank on immediately. (I really miss that feeling...) Ever since the Hella pump rebuild it's taken a little longer, but today, wow...

What are the common causes of a long crank? Thanks again for your input everyone!
1998 Volvo S70, N/A, 5-speed, 183K
2007 Volvo S40, 2.4i, 5-speed, 97K

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sleddriver
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sleddriver

Re: 98 S70, N/A Long crank... engine Temperature Switch related?

Post by sleddriver » Tue May 10, 2016 5:41 pm

What's the definition of a cold start in Queens this time of year?

Disconnect the ECT cable and see if it'll start. If so then it's Tango Uniform. If the sensor resistance is too low when cold, the ECU will think the engine is warm/hot and not dump in extra fuel (by increasing the duty cycle to the injectors). Pulling the harness, causes the resistance to go to infinity, telling the ECU the engine is VERY cold and to "pour-on-the-gas".

To my knowledge, the 98's only have one engine temp sensor and EVERYTHING engine/coolant/cold/hot is based on it.
1998 V70 T5 226,808 miles. Original Owner.
M1 10W-30 HM

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theWIFES_S70
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Re: 98 S70, N/A Long crank... engine Temperature Switch related?

Post by theWIFES_S70 » Wed May 11, 2016 8:19 am

sleddriver wrote:What's the definition of a cold start in Queens this time of year?

Disconnect the ECT cable and see if it'll start. If so then it's Tango Uniform. If the sensor resistance is too low when cold, the ECU will think the engine is warm/hot and not dump in extra fuel (by increasing the duty cycle to the injectors). Pulling the harness, causes the resistance to go to infinity, telling the ECU the engine is VERY cold and to "pour-on-the-gas".

To my knowledge, the 98's only have one engine temp sensor and EVERYTHING engine/coolant/cold/hot is based on it.
Well, a cold start as in, starting the car for the first time in two days! :D OK, will try that. Thanks for the advice.
1998 Volvo S70, N/A, 5-speed, 183K
2007 Volvo S40, 2.4i, 5-speed, 97K

jblackburn
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Re: 98 S70, N/A Long crank... engine Temperature Switch related?

Post by jblackburn » Wed May 11, 2016 9:30 am

For sure - a bad ECT left me with all kinds of starting issues.
'98 S70 T5
2016 Chevy Cruze Premier


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

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sleddriver
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Re: 98 S70, N/A Long crank... engine Temperature Switch related?

Post by sleddriver » Wed May 11, 2016 12:18 pm

I meant how cold is it in the mornings in Queens?
1998 V70 T5 226,808 miles. Original Owner.
M1 10W-30 HM

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theWIFES_S70
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Re: 98 S70, N/A Long crank... engine Temperature Switch related?

Post by theWIFES_S70 » Wed May 11, 2016 8:52 pm

I filmed a video of the crank... (This morning it was 55 degrees.) What do you guys think? I feel like it's fuel related (the engine, once at operating temperature, purrs like a kitten and starts like, well, like the groaning buffalo that our cars like to mimic)... I should just pony up the money for an OEM sensor, huh? :cry:
1998 Volvo S70, N/A, 5-speed, 183K
2007 Volvo S40, 2.4i, 5-speed, 97K

jblackburn
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Re: 98 S70, N/A Long crank... engine Temperature Switch related?

Post by jblackburn » Thu May 12, 2016 10:27 am

Flip the key on (to II) and make sure you have fuel pressure at the end of the fuel rail before replacing the temp sensor. A bad fuel pump check valve can do things like that as well.

That start doesn't seem too bad - mine took 45 seconds to a minute to get going when the sensor went bad - on a 70* day!
'98 S70 T5
2016 Chevy Cruze Premier


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

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theWIFES_S70
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theWIFES_S70

Re: 98 S70, N/A Long crank... engine Temperature Switch related?

Post by theWIFES_S70 » Thu May 12, 2016 10:34 am

jblackburn wrote:Flip the key on (to II) and make sure you have fuel pressure at the end of the fuel rail before replacing the temp sensor. A bad check valve can do things like that as well.

That start doesn't seem too bad - mine took 45 seconds to a minute to get going when the sensor went bad - on a 70* day!
Hey jblackburn, this thing?
Image

We only need this if we have taken the air pump out, right? I miss the instantaneous start we used to have before the fuel pump/relay hiccup. Maybe we should be putting the fuel pump in the "always use OEM" section, too, huh? I will keep an eye on it but won't worry about it too much. I really appreciate your feedback!
1998 Volvo S70, N/A, 5-speed, 183K
2007 Volvo S40, 2.4i, 5-speed, 97K

jblackburn
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Posts: 14049
Joined: Sun Jun 08, 2008 3:54 pm
Year and Model: 1998 S70 T5
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jblackburn

Re: 98 S70, N/A Long crank... engine Temperature Switch related?

Post by jblackburn » Thu May 12, 2016 10:45 am

Yes, splicing a check valve into a fuel line could work.

But in the meantime, just flip the key to II, don't crank, and look near the throttle body end of the fuel rail - there's a little blue cap and a port you can depress with a rag in hand to see if there is strong fuel pressure there or just a dribble.
'98 S70 T5
2016 Chevy Cruze Premier


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

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