VR Statesman 304 – Flooding on startup?

[MannyParticipant AdelaideVR Statesman 5.0 View build HERE Member since: July 19, 2016 Posts: 9]

Hi, Apologies if this is in the incorrect area. I’ve a 304 Statesman with (for me) a perplexing fueling issue.

Starts fine cold. If shutoff and restarted at operating temp will not start. If i remove the Fuel Pump relay the car will start and run for up to 5-10 seconds. If i replace the relay while running car will bog down for 15-20 seconds but eventually return to normal running.

Does not bring up any error codes when shorted.

I initially thought this a failed FPR, replaced stock reg and rectified the issue for a week then failed again. Replaced with another fuel regulator but did not fix the issue. Replaced injectors and while improved running, did not fix starting issue.

I’ve recently fitted billet rails, brained lines, an A1000 and new injectors but issue remains. Pump and filters are essentially new. Thankfully i’m fitting a old TA45 i’ve laying round in the near future so the fuel system isn’t entirely wasted.

I’m stumped. Has been suggested possibly blocked return line but the Fuel Pressure Gauge doesn’t show a spike. Infact the Fuel Pressure drops off quite rapidly after prime?

Thinking it has to be electrical at this point as everything else is basically new?

Any thought on this issue appreciated.

 

Thanks

Manny

[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

What is the actual pressure when the engine is running?

I’d suggest that the stock FPR with A1000 pump might be on the small side possibly causing excessive fuel pressures.

Do you have a non-return valve in the supply side after the pump but before the rail?  If not that would explain why the pressure drops after priming.

[MannyParticipant AdelaideVR Statesman 5.0 View build HERE Member since: July 19, 2016 Posts: 9]

What is the actual pressure when the engine is running?

I’d suggest that the stock FPR with A1000 pump might be on the small side possibly causing excessive fuel pressures.

Do you have a non-return valve in the supply side after the pump but before the rail?  If not that would explain why the pressure drops after priming.

Standard pump. Aeromotive A1000 Regulator that came off another project.

Fuel Pressure is set at 47psi.

Using standard configuration, Feed into drivers rail, crossover into passanger rails, into reg then back to tank. Reg is bypass.

Don’t have non return valve.

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[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

Right, my bad.

Standard pressure is 43psi with no manifold reference (at idle with the manifold reference hose fitted you will see less fuel pressure) try that and see how it goes.

 

BTW, what injectors are you using?

• This reply was modified 8 years, 2 months ago by  Immortality.

[MannyParticipant AdelaideVR Statesman 5.0 View build HERE Member since: July 19, 2016 Posts: 9]

Injectors are VT items. I’ll try the black tops and drop the rails too 43psi in the morning.

Honestly have no idea at this point.

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[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

Do you know the injector part number?

It is very possible that those injectors flow more than standard + a higher fuel rail pressure will mean it’s getting to much fuel.

[MannyParticipant AdelaideVR Statesman 5.0 View build HERE Member since: July 19, 2016 Posts: 9]

Possibly. But the issue remains with standard 304 injectors and standard pressures.

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[MannyParticipant AdelaideVR Statesman 5.0 View build HERE Member since: July 19, 2016 Posts: 9]

Further to this.

Checked return line with external line, Clear.

Double checked injectors for leak during prime, All fine.

Pretty much ruled out all mechanical issues, almost has to be electrical but not sure how to go about diagnosing electrical issues?

Another theory is fouled plugs but that doesn’t work with the fact the car runs fine on cold start.

Picked up a second hand ECU form a VS v6, i’ll swap the memcals over and give that a try see if the driver is shorted.

 

 

[bombasticParticipant bombasticHolden Commodore VR Wagon View build HERE Member since: September 11, 2016 Posts: 3]

Hi Manny

Changing standard items on injection systems brings up problems of a wierd nature sometimes. But knowing how a problem that would develop on the standard for your car might reveal a mod issue that can be worked around.

For example I am noting that you are using non standard fuel pressure regulator. In standard set up if the fuel pressure regluator develops a leak in the units internals fuel will leak up the vaccum control line.

The symptoms might be; starts well cold  because the fuel/oxygen mix is richer but starts poorly in warm or operating temperature.

To test; Depress accelerator pedal slightly during cranking/starting, when engine is at operating temperature or warm day. If engine starts the fault is confirmed/maybe.

If engine exhibits rough idle after starting it also could indicate the same problem. But generally once running after a 20 seconds all is well.

To see proof of this problem, if you disconnect the vacuum hose to the regulator after the engine has been turned off for an hour or two, a little fuel will flow from the vacuum line hose. No fuel should be present. (Care not to loosen any pressurised hoses)

After the fuel has come out of the vacuum hose the engine should start even when hot. (Caution; Beware fuel ignition in engine bay should fuel contact sparks or exhaust manifold. Ensure Ignition switch is tured off and not in accessory position before disconnecting fuel pressure regulator vacuum hose)(Fire extinguisher is handy)

Note; If installing non standard units/regulators it is essential to correctly connect any inlet and return hose to allow for flow in and out in any modification. Any standard hose just blocked off will cause issues in flow. It may also prevent the ability to diagnose problems.

In old cars more than five years old. Crap fitted by Holden to new cars can be vacuum hoses that simply fall away behind the fuel filler to fuel tank. Plastic guard may need removal for view. If any fuel return hose leaks it can be a serious safety issue. Although vacuum lines may only leak fuel vapour it can ignite.

Similar problems can arise when there is an inlet manifold leak. Intermitancy of the problem can change on engine temperature. Sometimes green coolant can be seen around manifolds that leak.

My 2cents worth.

Good luck.

 

[MannyParticipant AdelaideVR Statesman 5.0 View build HERE Member since: July 19, 2016 Posts: 9]

Thanks for all the tips, I’ll give ti the once over agian but 99% it’s not mechanical at this point

Done all the other basics like compression test etc.. Next is dump exhaust/intake see if there is a restriction there (dead cat?) causing the over fueling then move onto the ignition system.

Attached the diagnostics from today, problem being today is one of the days the problem didn’t arise..

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[MannyParticipant AdelaideVR Statesman 5.0 View build HERE Member since: July 19, 2016 Posts: 9]

Just a follow up on this encase anyone is interested.

Issue was the coolant temperature sensor. Replaced and all is well in the world

Thanks
Manny

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[cava454Moderator 93 VR BT1 View build HERE Member since: February 20, 2015 Posts: 2 390]

<p style=”text-align: left;”>Don’t you love it when you bust a nut trying to find a problem and it ends up being a shitty little $5 sensor.</p>

[vs manta 218Participant Vs hsv manta View build HERE Member since: March 2, 2015 Posts: 796]

<p style=”text-align: left;”>Have had the same years ago, coolent temp was telling ECU it’s minus 35 degrees and ECU thinks fuck yeah and pumps in loads of fuel</p>
<p style=”text-align: left;”></p>
<p style=”text-align: left;”> Myn was back firing then when changing gears sometimes just stall</p>

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