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Matt, Engineer
Category: Classic Car
Satisfied Customers: 21881
Experience:  BEng Hons mechanical engineering 20 years repairing my own cars and others, 8 yrs in formula 1 engin
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I have a 1971 p1800 starts cold runs well. When I shut it

Customer Question

I have a 1971 p1800 starts cold runs well. When I shut it off and
JA: Will the headlights turn on? Is the battery fully charged?
Customer: sorry. It's hard to start hot.
JA: What is the model of your '71 Volvo?
Customer: P1800 b20 eng.
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: Yes, I found the Throtel valve switch had cut wires. I found on a forum a wiring diagram and re wired. That's it solar.
JA: Anything else you think the mechanic should know?
Customer: The car has been sitting a wile i had to redu all vacuume lines.
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Volvo Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: Classic Car
Expert:  Matt replied 1 year ago.


I'd suggest to take a look at the coolant temperature sensor as this will help control the fueling as the engine warms

check over the wiring and connector for damaged insulation and or corroded connections 1st and if this looks OK then I'd replace the sensor as they're not expensive

it might also be worth replacing the spark plugs if in any doubt

Customer: replied 1 year ago.
Matt thank you for your advice. I'll check the sensor.Added info the plugs wires and cap are all new.
Expert:  Matt replied 1 year ago.


if the sensor doesn't help then I'd also check that the fuel pressure is correct with a running engine too as it should be about 2 bar ( 30 psi)

Expert:  Matt replied 1 year ago.


do you still need help?

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