Engine needs lots of throttle for cold start, ??

[JaviP]

Hello everyone,

I need help. I am stumped. Ok so I have a 2003 chaparral with twin 2003 5.0 volvo penta engines. So the port engine starts great no problem cold or warm it starts at the turn of the key, first time everytime. The starboard engine is what is giving me the problem starting. When the engine has been sitting off for more than an hour or so I have to give a good amount of throttle to get it started. So since the engine hadnt been serviced in a while I changed the spark plugs, oil and oil filter also changed the fuel filter. So after all that its still giving me the same problem. The only thing I noticed was that the fuel pump was getting really hot really fast. The port engines fuel pump does not get nearly as hot. So I swaped the starboard high preasure fuel pump with the port high presure fuel pump to see if it was a bad fuel pump. Nothing, same problem. Its getting hot and if i leave the engine sitiing for more than an hour I need to throttle it again while cranking the engine to get it going. Only thing Im thinking is maybe the low preasure fuel pump is bad? or there is a clog in the line AFTER the pump to the engine? Would a clog between the pump and the engine make the fuel pump get hot like that? Or give me a hard time starting when its cold? Once I get it going it runs perfect. Any help would be greatly appreciated. Thanks guys...

 

[Don S]

Re: Engine needs lots of throttle for cold start, ??

Did you check the automatic choke to see if it was working properly?

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

Nope that I have not checked. Where is that located? And what should I look for?

Would that cause the fuel pump to get hot??

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

My mech says it's a "*It's a MPI engine, no automatic choke, multiple port fuel ignition engine"... My engine is a Volvo penta 5.0 GXi.

 

[Don S]

Re: Engine needs lots of throttle for cold start, ??

My engine is a Volvo penta 5.0 GXi.

Happens everytime I try to assume something. In this case I assumed you had a carbed engine, and that more throttle meant pumping the throttle.

Now, it time for a full Model number or a Volvo SN so I know exactly what you have.

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

ur just trying to help which is much appreciated. But that is exactly what I do is pump the throttle to get it going on a cold. Once it's warmed up I can turn it off and on with no throttle at all...

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

SN# 4092014218 5.0L GXI 2003 Volvo penta..

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

Is there a diagnostic software i can get to help me with this?I see people posting about rinda technologies . Diacom. Will that work with my engine?

SN# 4092014218 5.0L GXI 2003 Volvo penta..

 

[Don S]

Re: Engine needs lots of throttle for cold start, ??

The Diacom software is nice, but unless you already have a laptop (one you can view in the sunlight) and the experience to use the program, it's probably not what you need. It is also not something you hook to the engine and a screen comes up and says "This is what your problem is" YOU still have to read and interpret the information it gives you.
A better choice would be the Techmate from Rinda. Much cheaper, you can read it in the bright sunlight, will give you the same info as the Diacom software, it's just the screen is smaller and may take you a little longer to troubleshoot. But if you aren't a trained mechanic, that's the least of your your problem.
http://www.rinda.com/marine/mtspec.htm
You are also going to need a quality DVM, and fuel pressure gauges for EFI, along with some other specialized tools and test harnesses.
Then, you will need a manual. That's the easy part, you can download it right here.
Assuming you have a 5.0GXi-B or C, (you don't say, and your SN has a wrong number in it somewhere as nothing comes up) here is the manual you would use.
http://www.4shared.com/file/83596359/cdacddfb/7742218_EFI_Diagnostics.html

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

Thanks, and from the issues I explain above, fuel pump getting hot and the cold start needing throttle pump to get it going would it lead you to think that it's a fuel problem after the pump? What are the things that can cause the pump to get hot? Blocked line After the pump? Low preasure pump going bad?

 

[6meter]

Re: Engine needs lots of throttle for cold start, ??

Pumping the throttle on any injected motor does zip.

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

Ok so here is what my mech did. He tested fuel preasure and he says that the low preasure pump is not giving the correct preasure. He says the low preasure pump drops to 0 at a point when the engine is running and goes no higher than 2. We know it's not the pump because we got the pump from my port engine and tried it there and it does the samething. So what do you guys think it can be??? He says the volt going to the pump is good. Cloged line? But if it would be cloged line wouldn't the high preasure be lost to?

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

Pumping the throttle on any injected motor does zip.

well tell that to my boat, which won't start for nothing UNLESS I give it throttle while cranking the engine....

 

[Don S]

Re: Engine needs lots of throttle for cold start, ??

Gas in the fuel pump is what cools it. If it's getting hot, it's probably getting air in it. OR, the motor in the pump is bad.
Pumping the throttle does nothing, there is no carb and no accelerator pump. The accelerator pump in a carb is what pumps fuel when you pump it.
What is happening is when the throttle is up, the ECM sees through the TPS that the throttle is wide open and trying to clear a flooded condition.

EFI systems seldom get fixed in a forum. WAY to many variables, including the ones trying to do the testing without the proper equipment or abilities.

 

[JaviP]

Re: Engine needs lots of throttle for cold start, ??

mech is going to be pluging it into the computer tomorrow lets see what that yeilds...

 

[Icefire55]

Re: Engine needs lots of throttle for cold start, ??

kinked fuel line?
the gas does cool a fuel pump so if it's running really hot, could be that it's not pumping or it's kinked/clogged

 

[6meter]

Re: Engine needs lots of throttle for cold start, ??

well tell that to my boat, which won't start for nothing UNLESS I give it throttle while cranking the engine....

Said thought meant that no gas would be pumped. The only thing your boat is reading different is the throttle position sensor. Probably a computer glitch. And like Don S says, doubtful many would have the tools or knowledge to fix it. Good luck!