VN fuel pressure regulator

[85commolux]

Hi all, would like some help with a problem I have. I am 99% of the way through fitting a VN series2 (or possibly VP as that is what the Memcal is out of) to my Hilux. I had some probs with ECU but I am pretty sure that has been sorted and I had issues with MAP sensor but I am pretty sure that was just the vacuum line to the heater controls (mine is cable operated).
Anyway today I took the ute down to the exhaust place and it took about 10 goes to get it to start, just kept stalling straight away. When I went to pick it up it wouldn't start at all, sprayed aerostart into intake and away it went then died. This happened several times until we crimped the return line and away it went, then down the road I gave it a bit of right boot and it almost stalled then kept going. I checked the vacuum line to the regulator and it smells of fuel. So my question is, regulator buggered?
Any help would be appreciated.

[Cheap6]

With the fuel in the vac. line it does sound like the reg. diaphram is leaking. Can you put a presssure gauge on the fuel feed line? It should read inlet manifold pressure + 320kPa i.e. ~422kPa absolute/320 kPa gauge with the engine off, ~352kPa absolute/250kPa gauge at idle, A/C off out of gear (auto.). It should also hold pressure with the engine off or at least bleed down very slowly.

[Zuicider]

map sensor is plugged into the elbow not the heater controls

[85commolux]

map sensor is plugged into the elbow not the heater controls

The vacuum line for the heater controls is plugged into the elbow too. At least I think thats what the line is for, its the hose just above the hose for the fuel regulator. If I am wrong and this has to be plugged in somewhere else then could someone tell me please.
Thanks

[85commolux]

With the fuel in the vac. line it does sound like the reg. diaphram is leaking. Can you put a presssure gauge on the fuel feed line? It should read inlet manifold pressure + 320kPa i.e. ~422kPa absolute/320 kPa gauge with the engine off, ~352kPa absolute/250kPa gauge at idle, A/C off out of gear (auto.). It should also hold pressure with the engine off or at least bleed down very slowly.

I'm not sure if I can, the car just won't run without the fuel line crimped and I am assuming that this would give a false reading.

[FXST01]

The fuel pressure regulator and the heater vacuum should be connected at the elbow (each with their own connection).
The MAP sensor should be getting its vacuum from the throttle body (near the firewall) its connection points at the firewall and is hidden from easy viewing.

[85commolux]

Today I went to the wreckers and got 2 pressure regulators, these things supposedly don't stuff up very often and I had hoped that I would get 1 good one out of it. I cleaned the TB and IAC and put it back together and it now runs for a few seconds and even idled a couple of times, till I tried to rev it. I am now thinking that it might be a blocked fuel filter as the tank I put in had been sitting around for a while. I did put a new filter on it. I will be peed off and happy at the same time if that is all it is.

[Cheap6]

I'm not sure if I can, the car just won't run without the fuel line crimped and I am assuming that this would give a false reading.

Because it's referenced to manifold pressure, you would get at least part of the story with the 422/320kPa, engine off, pump running (bridged relay terminals). That would tell you if the reg. was leaking and also check the filter and pump at the max. pressure (OK, with a lower flow rate) that it will see.

The vac. hose for the heater to the elbow - small spigot, 3-mm dia.? - sounds right. With it unblocked, vac. leak => high MAP voltage/pressure at idle.

Hope it is just the filter.

[85commolux]

Put new filter on this morning and still no go. Cleared codes on ECU and is coming up with 33 again. I pulled the vacuum hose off the regulator and fuel actually came out of it so that one is cactus. I still have the other one to put on, working off the theory that they can't all be rooted. fingers crossed

[85commolux]

Okay so I put the other regulator in and still no go. After I cleaned the TB I can hear and feel the IAC valve knocking when in diagnostic mode but not any other time. It has me stuffed

[delcowizzid]

thats a map sensor voltage to high code

[Zuicider]

85commolux are u loated in wa by any chance?

[85commolux]

No I'm in TUMUT NSW. Why is that?

[Cheap6]

If the MAP voltage is registering as high it will be overfuelling. That would explain the hard/no start and perhaps even the wet fuel pressure reg, although not the start by crimping the return line .

If you unplug the MAP sensor terminal connector the ECM will use the TPS instead to estimate the air and thus fuel flows - might be useful for diagnosis, maybe to at least get a running engine.

I have that code 33 will set if:

Codes 21 or 22 aren't active

Engine is running

MAP signal voltage indicates that the manifold pressure is nearly equal to atmospheric pressure and...

TPS indicates the throttle < 2% open

Wiring:

C14 at the ECM, grey wire at the MAP sensor is the ~5V reference

C11 at the ECM, light green wire at the sensor is the input signal; - ~1-2V @ idle => ~4-5V at WOT/engine off.

A11 at the ECM, black wire is the sensor earth

The 5V reference is shared with the TPS, the earth is shared with the MAT sensor

The XXreferenceXX sorry, I mean signal voltage should change with vacuum applied to the sensor port eg. if you sucked on the end of the vacuum hose that goes to the manifold, the voltage between:

the LG wire and the black wire, at the MAP sensor

and between C11 and A11 at the ECM

and between the LG wire (at both the sensor and ECM) and the battery earth terminal (to check for a poor ECM earth

should drop as the vacuum (suction) is increased and all be same (within 0.1V or so).

Any huge manifold vacuum leaks anywhere?

It won't cause a hard/no start but the length (actually volume) of the vacuum hose affects the sensor response and should really be kept the same length as it is in the donor Commodore (used in transient load changes).

[85commolux]

I put a vacuum gauge on and with the fuel line pinched got it to run (allbeit very rough) and it was at 22 inches of Hg @ idle. When I cracked the throttle it went down to 0 then back up to 22, so I guess it isn't a vacuum leak. Regarding the fuel smell in the regulator, I took the vacuum hose off my VX last night and it also has a fuel smell and it runs fine. At one point I took the crimp off the return line and it kept running but stalled again after awhile, then wouldn't go again till I crimped it again. So you are saying to disconnect the MAP sensor alltogether and see if it still does it?

[85commolux]

OK I disconnected the MAP sensor and it idles but I can't rev it, plugged it back in and it just stalls. I have replaced the ECU with a second hand unit that my mechanic had, as I had troubles with the old one showing a 51 code and checked the memcal and it was fine.
How many earth wires are supposed to be on the system?. I have one on the engine mount, one going to the battery and one from the battery to the body.

[Cheap6]

Maybe also try it the other way around i.e. reconnect the MAP sensor and disconnect the TPS. The engine should run fine without the MAP sensor connected off The TPS signal. Obviously it can't do that if the TPS signal isn't there/working.

The TPS codes require:

21:

TPS > 2.5V

and rpm < 1600

and MAP < 60 kPa

for 2 seconds

22:

engine running and TPS < 0.15V

Also for 2 seconds

(That's for an early VN)

The earths I'm not sure about. I recall one earth terminal on the water pump/timing case but that may be for a different series engine and possibly derived via the other earth wires you have already connected.

Edit: one ECM earth is under the DFI module on one of the bracket studs. That's for A12, D6, and D10 (VP).

[85commolux]

I will try that tommorrow. I am very grateful for the help and suggestions so far.

[Cheap6]

Let us know how you get on. I'm curious to find out what it was.

[85commolux]

I tried having the TPS disconnected and the MAP connected and I get the same thing, starts runs rough and idles high then dies when I rev it. There is also a fuel smell in the vacuum line to the MAP. I am picking up a new regulator on Friday so I will see how that goes. I checked the voltage to the MAP and was getting 4.7 v, then sucked on the line and the volts dropped.

[Not_An_Abba_Fan]

I'd also look at the fuel pump. Crimping off the return line boosts pressure in the fuel rail so maybe the pump is on its way out and doesn't pressurize the system enough.

[85commolux]

This might sound silly but could it have anything to do with the length of rubber hose I have used. This problem has only come on since I turned the tank around and now I have 1.2 m of high pressure hose running to my steel line.

[Not_An_Abba_Fan]

If it is proper high pressure EFI fuel hose, it shouldn't matter. Unless it is a larger diameter than the steel line, then I think it will lose pressure.

[85commolux]

No its 5/16" premium EFI hose.

[Not_An_Abba_Fan]

Could be just coincidence.

The pump hasn't been run dry?

Just had another thought, the vacuum hose off the regulator is connected directly to manifold vacuum isn't it?