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-   Volvo 240, 740 & 940 (https://volvoforums.com/forum/volvo-240-740-940-12/)
-   -   1990 740 is hard to start (https://volvoforums.com/forum/volvo-240-740-940-12/1990-740-hard-start-54799/)

badrad 06-11-2011 07:02 AM

1990 740 is hard to start
 
Once the car starts, it runs fine but it usually takes about three times before it starts. I have changed the timing belt, (it was due to be changed anyway) but this hasn't helped the hard start issue. This is my first Volvo and I am not too familiar with all of it's quirks yet. Any sugguestions. My mechanic says may be the fuel pump. If so, is that hard to do for someone who is somewhat mechanically inclined.

Burn Stains 06-11-2011 09:03 PM

As an extremely basic problem eliminator, check the fuel pump fuses and clean them (contacts, holder and all). Possibly consider replacing them with standard glass fuses. Otherwise, do some research, please. You will find plenty of suggestions on fixes and troubleshooting, then we would be glad to help you on any other problems you have.
Here is a few though
http://www.swedishautoparts.com/740/...ine+hard+start
http://www.matthewsvolvosite.com/for...hp?f=2&t=14033

swiftjustice44 06-11-2011 10:26 PM

As an alternative, you might consider searching this site as there have been no less than 4 threads on the subject in the last 6-8 months. Your mechanic might consider checking TSB's for your car. Assuming you have an n/a 740 GL, you have the single cam B230 w/ Regina ignition. Volvo identified an issue some 18 years ago concerning the cold start injector...was running too long. The solution was to rewire the injector to get it's power from the starter to cut down on run time.
Your car has a single intank high pressure fuel pump w/ filter sock but it also has an inline filter under the car as well as a one way check valve nearby to assist in faster restarts.
Have you pulled codes from the OBD?

Typhoon 06-12-2011 09:21 AM

Point of issue, the 1990 will likely be LH 2.4. LH had no cold start issues because the cold start injector is rarely used (sub -15c). LH 2.4 commands extra pulse width and also a double injector pulse for cold starts. With LH 2.4 and hard cold starts, I always suspect coolant temp sensor first. If it's signal is missing of ECU thinks the input is flawed, it subsitutes the value for coolant temp as 20c for ALL of it's fuelling. This shows up as poor mileage and hard cold starts. But I mentioned all this in one of the posts you alluded to!
A classic symptom for bad cold starts with LH2.4 and a bad temp sensor is a long crank, reluctant to catch and when engine catches, a low idle for a few seconds and roughness which smooths out as ECU opens up pulse width as it comes out of cold start map and into cold idle map.
As I keep saying, if an engine runs fine otherwise, fuel pump WILL NOT cause cold start issues, fuel demands are way, way higher at full throttle than any cold start. Mechanics always say fuel pump because they have no clue, can sell you one, then make more money trying to find the actual problem......not having a go at you there swiftjustice, more OP's mechanic.

swiftjustice44 06-12-2011 12:04 PM

Andrew, I think the Regina/Bosch issue may depend on market. Perhaps in Oz you were blessed with only a smattering of Regina cars...here in the US we were not so fortunate. Engine: Fuel Injection
As you can see, non-Cali emissions cars (49 state legal) that were n/a, were pretty much all Regina here in the US.
In actuality, I have nothing against the Regina set up other than it seems to be a bit more difficult to "play" with...actually seems to be a bullet proof overall.

Typhoon 06-13-2011 12:29 AM


Originally Posted by swiftjustice44 (Post 275824)
Andrew, I think the Regina/Bosch issue may depend on market. Perhaps in Oz you were blessed with only a smattering of Regina cars...here in the US we were not so fortunate. Engine: Fuel Injection
As you can see, non-Cali emissions cars (49 state legal) that were n/a, were pretty much all Regina here in the US.
In actuality, I have nothing against the Regina set up other than it seems to be a bit more difficult to "play" with...actually seems to be a bullet proof overall.

I think you are right, I believe Regina was a 1990 year cross over. In fact Regina is nothing more than LH 2.4 with integrated ignition control, think of it as an evolution of LH.
We got Regina here but the cutoff was probably more clear than there, when our 740's were discontinued in 90, the 940's all had Regina.
Regardless, the systems fundamentally work much the same, I think the codes are similar too?

lev 06-13-2011 06:59 PM

Hard cold start, I first look at the Engine Temp Sensor under the third rail of the intake manifold.

badrad 06-28-2011 12:44 PM

Thanks, i will check that out

Tdanze 06-11-2012 10:43 PM

It was the poor connection to the cold start device for me.
 
I have been enjoying/cursing the Volvo brand since I bought this car from a very responsible owner who was buying another Volvo. I would not have spent the money he spent at the dealer for maintanance and repairs. I currently am less than 2000 mi. From 300k. The cold start valve and timing belt replacement has restored this car to original performance. Yes, scalded dog at high RPM's, but good low end power out of the hole as well. You could go broke running at the fuel pump on this car. Simply jiggle the connection wire to the cold start valve. Voila! Problem solved,(until the next one). I've been dealing with this for a couple of years. This was way too easy. BTW, CSV is located center of the intake manifold on the bottom.


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