car won't start until the engine cools down

memasarif · Post by **memasarif** » 19 Mar 2011, 22:18

Dear Users,
Here is my problem that i have in 1994 volvo 960
The problem is.. first thing in the morning, go to start the car it cranks and starts up perfect... if I shut it off after even 2 minutes of it running and I try to restart it, nothing.... it will crank and crank and crank but won't fire... if I wait about an hr or so and try to start it again I have to keep the motor cranking until it acts like it wants to start then I have to feather the gas to get it to fire... it looks like the fuel pump relay has been changed, so I am suspecting the IAC valve next, but I have heard also that the valves on these engines stick and won't close properly.. but will fully reseat after the engine is cool enough but yeah... I can start fine first thing but if I shut it off and try to restart it, it just cranks if I wait another twoo three hrs... try to start it it will fire no problem... its getting gas and spark so its either something electrical or the valve thing is true... or somethin else

Post by **billofdurham** » 20 Mar 2011, 11:51

Welcome to Matthew's Volvo Site.

Have you checked for fault codes using the On-Board Diagnostic (OBD) unit in the engine compartment? This is a first step in diagnosing these cars. Instructions for its use are pinned at the top of the forum.

Bill.

memasarif · Post by **memasarif** » 20 Mar 2011, 14:42

I pushed the button but no signals so it seems I do not have any error codes? I dropped the car to mechanic and I think he cleared the codes(i do not know why?). How can I get the codes back? or any idea to check?
Thank you.

Post by **kcodyjr** » 20 Mar 2011, 21:54

Just keep driving it, the codes will come back.

This sounds vaguely familiar. My 1981 turbo coupe did this for awhile when it was Dad's daily driver.

If memory serves - and we're talking a good 20 years - the fix was injector seals. That was the B20FT though, and I've never had a 700 or 900 series.

It does make a certain amount of sense; as it warms up, the seals soften, plus different metals expand at different rates and the plastic injectors really don't so much.

I can't begin to think what else might be affected by a lengthy cool-down, than temperature issues.

SkyVolvo · Post by **SkyVolvo** » 21 Mar 2011, 00:50

Perhaps since you checked for fuel and spark this isn't the issue, but I do like starting with simple, cheap things. I had a similar issue recently and knew that my fuel pump relay was fine. It turned out to be the radio interference suppression relay, which powers the fuel injectors. This was very easy to check: https://www.matthewsvolvosite.com/forums ... =2&t=32273

Just switch the fan relay with the radio suppression relay and see if the car starts. It worked for me, and I was able to order a replacement from FCP.

Colonialgirl · Post by **Colonialgirl** » 21 Mar 2011, 01:50

I had a similar problem with my 1984 760 GLE with the V-6; Finally figured out that the starter solenoid wasn't making good contact with the wire to the coil. The usual circuit is bypassed when you are starting the car. Don't ask me why it works after cooling down, after it starts and you release the key the voltage is supplied via another circuit.

danr960 · Post by **danr960** » 21 Mar 2011, 09:13

memasarif wrote:I pushed the button but no signals so it seems I do not have any error codes? I dropped the car to mechanic and I think he cleared the codes(i do not know why?). How can I get the codes back? or any idea to check?
Thank you.

At the very least you should get a blinking LED. The no stored codes signal is 1-1-1. Are you getting that? Maybe you are not doing it correctly, or there is some corrosion on the test lead and it is not working correctly?
Have you tried other suggestions made earlier? What have you look into and what have you not?

One thing I do with my '94 is to clean all under the hood electrical connectors, these connectors are prone to slight corrosion which causes electrical resistance and heat from a hot engine will make that resistance worse. There is also the fuel pump relay that can fail from heat.

DanR '94 964 356,000 miles (122,000 on the new engine)

memasarif · Post by **memasarif** » 21 Mar 2011, 13:45

For the check engine light I pressed the button but not even 1-1-1. You press the key and then release and count the lights on? Is that right?

1)interference suppression relay and fan relay switched but it did not help at all.
2)Starter selenoid? How do I check that or fix that?
3)Injector seals also how can that be fixed or check?

Thank you..

memasarif · Post by **memasarif** » 22 Mar 2011, 19:28

Dear Users,

What I noticed is when I jump the car, after long cranking car starts but the engine dies after 7-10 seconds. Is this an indication of any part? Is it familiar to anybody? If I do not jump the car, after a while battery is dead.
Thank you.

gyrene · Post by **gyrene** » 16 May 2011, 15:43

My 91 940SE turbo was doing the same thing. My fix was a new ECU, it was losing ground. No problem with that since.