HELP - Vectra won't start.

lynnbearse · 03-28-2018, 01:30 PM

We have a 2004 Vectra with a Cummins 350 ISC 8.3 Liter CAPS fuel System and it won't start. It turns over but won't start. It is driving us crazy because it has been up to now intermittent. Engine shows no code. We have replaced the lift pump, replaced the fuel supply line. Checked the all the relays, wiring and everything we can think of. Has anyone had this problem or have any ideas. We sure could use any suggestions. Thank you in advance!!

Jim_HiTek · 03-28-2018, 09:37 PM

Check the banjo connector after the lift pump. Up on the fuel rail. If it's leaking air, you'll get that symptom. There's usually a bit of fuel nearby showing that it's leaking. A good mobile diesel mechanic should be able to pin point the problem given how simple diesel engines are. Plus it's not throwing a code so that should tell a mechanic something.

Here's an after market CAPS pump but have a tech determine if yours is bad or if it's a leak: https://www.ultrarvproducts.com/UP95...PS-Fuel-System

"The CAPS fuel system is known to be a weak fuel system as the factory lift pump only engages for the first 30-45 seconds after the key-switch is engaged. After this, the CAPS pump "pulls" the fuel and acts as the only pump in the system. By adding this heavy duty pump, not only are you taking away a lot of stress on the CAPS pump but you are also providing a steady flow of fuel that will help cool and lubricate the pump to increase the reliability and longevity of the CAPS pump. This adjustable pump is rated at 95 gallons of diesel fuel per hour and come preset at 15 PSI. Using a 1/8" Allen plug, you can make a quick clockwise adjustment to increase pressure or counter clockwise to decrease pressure."

If it were me, I'd try adding a simple external fuel pump near the engine as an assist before I'd pay $500 for that pump shown in the link above. Or try to find a generic replacement for the CAPS pump.

lynnbearse · 03-29-2018, 08:43 AM

Hi Jim

What do you mean by a simple external fuel pump and where would I find one?

As, I have already replaced the lift pump.

I have replaced the incoming fuel line, now I'm in the process of replacing the return line.

I have checked the banjo connectors and they are fine.

I appreciate the help, thank you !

Lynn

Podivin · 03-29-2018, 12:12 PM

How's the air filter - could it be plugged?

Jim_HiTek · 03-29-2018, 01:21 PM

Quote:

Originally Posted by lynnbearse

Hi Jim

What do you mean by a simple external fuel pump and where would I find one?

As, I have already replaced the lift pump.

I have replaced the incoming fuel line, now I'm in the process of replacing the return line.

I have checked the banjo connectors and they are fine.

I appreciate the help, thank you !

Lynn

First: It's hard to guesstimate what your problem might be...your engine is sufficiently different then mine (I use to have a 5.9 Cummins, now I have a Cat 3126) so take whatever I say with a grain of salt.

I used an Airtex External Electric Pump that I bought at Napa along with the fuel hose and brass adapters needed to match hose IDs. It preceded the lift pump. But I didn't need a super high pressure pump either. The one I used was a 8 GPM pump. I believe it pumped at 15 PSI but can't recall for sure.

Mounted it just below the engine's lift pump on the frame rail and wired it to a convenient IGN wire that happened to be nearby. It was to be an assist for the in-tank pump 20 feet away (at the front of the RV) and to assist the Cummins mechanical lift pump, giving it longer life.

It was pumping diesel and worked fine for the 12 years I owned the RV.

Matterbery · 03-29-2018, 03:04 PM

If that engine is a common rail system and the pump is putting the correct pressure to the common rail and the relief is not stuck open you could have a bad injector that is not letting the common rail build enough pressure to over ride the bad injector and put enough fuel to the other injectors for the engine to start.

lynnbearse · 03-29-2018, 04:40 PM

Thank you..... changed the air filter ! I have tried all the common stuff. I'm baffled!

lynnbearse · 03-29-2018, 04:42 PM

Thank you, its a Cummins ISC CAPS 8.3........ tried all the common stuff and i'm baffled!

lynnbearse · 03-29-2018, 04:44 PM

Thank you for your input it is appreciated. I ran the return fuel line today and will hook it up tomorrow! Fingers crossed, if not on the adding the external pump !

lynnbearse · 04-01-2018, 09:30 AM

New return line and fittings and no difference, UGH !

Matterbery · 04-01-2018, 09:37 AM

I don't know where you are at but I have about 40 years experience in the diesel field of repairs and could help but it is hard to post all of the troubleshooting that needs to be done.

Jim_HiTek · 04-01-2018, 04:53 PM

You might check for a Mobile RV Mechanic service in your area. Check on Google, than enter the names in RVServiceReviews.com

Not all services have good reputations and it's best to know what fellow RV'ers think of who you're hiring.

lynnbearse · 04-02-2018, 11:12 AM

Quote:

Originally Posted by Matterbery

I don't know where you are at but I have about 40 years experience in the diesel field of repairs and could help but it is hard to post all of the troubleshooting that needs to be done.

I'm in NE FL - where are you located?

lynnbearse · 04-02-2018, 11:42 AM

Quote:

Originally Posted by Jim_HiTek

You might check for a Mobile RV Mechanic service in your area. Check on Google, than enter the names in RVServiceReviews.com

Not all services have good reputations and it's best to know what fellow RV'ers think of who you're hiring.

Will do ! Thank you

Matterbery · 04-02-2018, 12:21 PM

North of new Orleans

Matterbery · 04-02-2018, 12:28 PM

You can call me back at 913 669 6402

Rjb71 · 04-29-2018, 09:54 AM

If your battery voltage drops to 10v while cranking it can give you a no start without any codes. Just a suggestion but I start there before looking at the fuel system

imnprsd · 07-21-2019, 10:30 PM

I know you said your engine would not start and you are sure you are looking for an electrical problem, you might consider replacing your ignition switch? (Only $25 at Freightliner).

If you key cylinder cylinder rotates and the bezel is tight, then maybe the internal workings of your ignition switch is not passing a clean +12V to your ECM?

I replaced my ignition switch and I think my engine became more responsive. The mechanic says you can lose voltage to the ECM and it will not throw a fault code unless the voltage drops really low.

Other electrical checks:

* Your Fuel Metering Device
* You can check your ECM Suppressor Diode from underneath the coach, but if that's blown your ECM could be as well. That's why they say you should not continue to start your engine over-and-over; i.e., without the suppressor diode your ECM can blow with more engine cranking.
* * Stator is the next stop if you are sure you don't have a fuel blockage problem. There is a Cummins Care procedure you can follow to check for the correct Ohms. It's not complicated, but everything is daunting the fist time around.

How do you know you do not have a fuel delivery problem:

*Clogged CAPS-Accummulator for example. This is what happens when algae becomes a problem; and for the last 10 years the most common solution to add a 2nd fuel filter. Do you have 2 fuel filters or just 1?

SEPARATE SORRY IF YOUR ENGINE STARTS AND THEN STOPS 1-MINUTE LATER:

On 2 occasions spaced 6,000 miles apart, my engine started then stopped.

The first time I changed my filters and after 4 attempts to start the engine she finally kept running and I avoided a tow.

I also took the coach to a mechanic, but he said there was no telling how long it would take to find the problem since the engine was running fine.

So off I went. Then I stored my coach for 6-months in Houston; picked it up and drove 3,000 miles to Yellowstone when my engine coughed going up the grade.

Three days later, in my Montana camp spot, the engine started and the stopped 1 minute later. The solution: I tightened the 3-Lift Pump Bolts (not too tight) and all is good again.

Thanks for suggesting I tighten the banjo bolts. I didn't think about that.
...And maybe your problem are 3 loose Lift Bolts. (Note: My bolt had very little torque on them, and I think I put a 3/4 turn on each one.) So air was leaking through the lift pump gasket!

Now I'm putting together a plan to add a Fass Titanium Lift pump; as I found some metal in my fuel filter signalling lift pump wear. So I thought I should install a FASS Titanium pump (KIT# TSD08095G) for $673 on line + $150 for the FASS fuel return line), which is not much more than paying a mechanic to replace the stock lift pump.

Please let us know what solution your came up with to fix your fuel delivery problems? I have your sister ship: 2004 Itasca "Horizon" with 8.3L-ISC (CAPS).

...AND: HOW DID YOU KNOW IT WAS TIME TO REPLACE YOUR FUEL LINES?
...And are they 5/8" or 1/2" fuel lines?
I need to know if I should replace mine? And maybe you can tell the improvement you experienced after you replaced your supply line? (IF ANY?)

Note: As you can see in the picture, my CAPS fuel return line is made of nylon (not copper) so it does not need to be changed.

imnprsd · 10-27-2019, 12:50 AM

Here's a link that explains what we did after we tightened the 3-Lift Pump bolts:

Cummins ISC - Engine Starts But Then Quits & Why We Upgraded To FASS TS Pump!!!! - iRV2 Forums

And because we were so please with the FASS "TS" pump we decided to add an Ag Diesel Solutions "Power Module" #12100 to our engine and we now have all the HP and torque we need.

Go to this thread for more informaion on"Chipping" your engine:

Cummins ISC Power Module Upgrade (+20%) Turned My 350HP Into 420HP ($700) - iRV2 Forums