1999 Volvo 5.0 gxi starting issues

[noot74]

Hey everyone. I’m about at my wits end with this boat. Bought it last summer told it needed a fuel pump. Replaced the fuel pump and it started a little difficult but then ran for 45 minutes. Turned it off and tried to restart. Fires off and dies. Does this around 10 times before it finally starts again. Does this every time. Last summer it would do it while boating along in the water. Just die.
have replaced all plugs and capn and the computer with the updated model after being suggested it by a local shop. They took it in and could not figure out the problem and wanted to begin replacing eveyr wire. Any suggestions?
thanks in advance!
corey

 

[alldodge]

Howdy
What is the motor serial number?

 

[BRICH1260]

GXI`s are totally computer (ECM) controlled. All the engines sensors must be working in unison, sending the correct signals to the ECM at the same time or it will not fire. It would help if you had a Rhinda diagnostic tool to plug in to see if it is throwing any codes.

 

[noot74]

Here is the numbers off of it.

 

[alldodge]

Thanks for the SN
GXI-E
Check your fuel pressure Low side 8 psi +/-4 , High side 50-60 psi

When its cranking does the tach show around 300 rpm?

Try starting after disconnection the cam sensor on the distributor

 

[noot74]

Alldodge,
when I am checking fuel pressure does that mean while it’s running? When it does fire off and run the low side is 10psi and the high is 50psi. When it’s sitting prior to starting the low side is non existent. When I turn the key sometimes it primed the pump and sometimes it doesn’t. When I’m cranking it over the low side will get to about 4psi. The tach is around 300rpm while cranking. I’m assuming the only sensor plugged into the distributor is the cam position sensor. I unplugged that and turned it over. Then plugged it back in and it fired right off and rpm stayed super high. Turned it off and repeated the process with same results. Tried a third time and back to not starting completely

 

[noot74]

Brich1206. I’m debating on getting the software or not. It’s just under $600 at this point. We shall see what happens. Partly I just want to buy it because we plan on keeping the boat.

 

[alldodge]

Pressure should be close with key ON (but may not stay there) and while running.

With the low pressure side not coming on, there may be a bad connection and would cause a problem starting

You do have a crank position sensor (CPS) and its on the front timing chain cover

The Cam sensor on the distributor is used, but it should start without it connected, it just takes more cranking to get it to fire.

Not wanting to throw parts at a problem, but without a scanner, its looking like the CPS

 

[noot74]

Is the crank position sensor under the timing chain cover ? Near the front of the motor ? The computer on top is brand new upgraded version as well.

 

[alldodge]

The CPS is on the front of the timing chain cover and looks like item 7

https://www.volvopentashop.com/epc/...asolineEngines/7744400/7744400_28/7744400_026

 

[noot74]

Alldodge. I really appreciate your help on this. It appears mine is just under the motor plugged in? Looks the same. Also, would the rinda diagnostic software help to determine if the cps is bad or not? I’m looking and it’s $170 to replace

 

[alldodge]

Yes the software would indicate a failure
The only test I found is to measure between pins B+C and it should be infinite, anything less and it needs to be replaced.

If the CPS has a bad connection it will also cause a failure to start

Your motor is a GM 5.0 and the sensor should also be Delco, Standard or Delphi.
I looked up a 1999 Chevy 1500 with 5.0 and came back with

AC Delco 2134761
Delphi SS10125
Standard PC123

There are also other makes. I would stop by the local GM dealer and get one, take part with. Should not be more then $50

There are other brands which are less, and things like same brands which have cheaper model numbers like Standard PC123T

 

[BRICH1260]

Brich1206. I’m debating on getting the software or not. It’s just under $600 at this point. We shall see what happens. Partly I just want to buy it because we plan on keeping the boat.

I broke down and bought one two years ago thinking I would use it to resolve some issues and then re-sale on ebay to get some of my money back. I ended up keeping mine as they do give a lot of assistance is diagnostic troubleshooting.

 

[noot74]

Ok. So was finally able to scan the motor and came back with two codes.
code 22 and code 41. Motor has 174 hours on it.
now the low pressure pump is not turning on when you put the key in the on position. It will only turn on while cranking. The pressure is 10lbs while cranking. High side is 55psi
now, if you hold the key in the crank position instead of returning it to normal it will start and stay running every time. Which I believe is bypassing all of the sensors and circuits in this position.
also looking at some diagrams it showed a purple wire that went to the starter and I don’t have one on mine. I’m cleaning up all the contacts as we speak. Grounds etc and hoping that helps. Any other ideas ?

 

[alldodge]

Code 22 - TP sensor low
Code 41 - IC open (another member has the same code and same motor which MUC is helping with)
https://forums.iboats.com/forum/eng.../10898723-volvo-penta-5-0-gxi-e-fault-code-41

if you hold the key in the crank position instead of returning it to normal it will start and stay running every time.

This is probably the entire issue
The LP pump stops and pressure starts dropping, then the ECM tries to keep the motor running by open/closing the TB.

I have GXI A thru D but don't have the E model. All A thru D use a single relay to power both pumps, but keeping the key to start would mean on the E model this is not the case. Trace the wiring on the LP pump and see where it goes

 

[noot74]

I will check more on this when I get home. I feel like at least we are on the scent of a solution!

 

[QBhoy]

Sounds like a throttle position sensor or IAC issue.
just out of interest. This new ecu you have. Is it defo the right one ? Are they not crazy expensive? What is upgraded about them ?

 

[noot74]

Good morning. I wanted to stop in and give and update. Both ground studs on the back of the block were in terrible shape. Replaced those and the fittings on the grounds. Did not resolve but gave me peace of mind.
I had read on this forum another guy with the exact same symptoms and ended up being a bad connection in the J connector (big blue plug). He created a jumper for the purple wire and problem solved. He had replaced everything he could.
My plug had some corrosion in it. Cleaned the male ends easily. For the female part took the dremel and a small wire brush fitting and teamed out each one. Applied some marine dielectric grease. All back together and bam. Fired right up and restarts every time. Tested it 30 times to make sure.
The new ECU has done suspension grommet things to help with the shaking as it sits atop the engine. Also something was better with the soldering joints to help.
Overall, I didn’t need to replace it but did anyhow.
This boat has been to 4 shops and one additional boat guru without the issue resolving. My dad came over and started looking through things and pulled the connector and said it was pretty ugly.
Thank you to everyone that helped with this and I really appreciate it!
corey

 

[QBhoy]

Is 1999 perhaps a little early for a GXi ? Can’t think. Wonder if it’s a mix and match you have

 

[Volvo cool]

Good morning. I wanted to stop in and give and update. Both ground studs on the back of the block were in terrible shape. Replaced those and the fittings on the grounds. Did not resolve but gave me peace of mind.
I had read on this forum another guy with the exact same symptoms and ended up being a bad connection in the J connector (big blue plug). He created a jumper for the purple wire and problem solved. He had replaced everything he could.
My plug had some corrosion in it. Cleaned the male ends easily. For the female part took the dremel and a small wire brush fitting and teamed out each one. Applied some marine dielectric grease. All back together and bam. Fired right up and restarts every time. Tested it 30 times to make sure.
The new ECU has done suspension grommet things to help with the shaking as it sits atop the engine. Also something was better with the soldering joints to help.
Overall, I didn’t need to replace it but did anyhow.
This boat has been to 4 shops and one additional boat guru without the issue resolving. My dad came over and started looking through things and pulled the connector and said it was pretty ugly.
Thank you to everyone that helped with this and I really appreciate it!
corey

I'm having the same problem with mine