Rough Running/Starting Issues (Fuel Injector??)

[BusinessConnected]

Hello All:
Range Rover (MY 1995 GEMS) has developed a slightly longer startup time in the last couple of weeks, culminating in not starting at all yesterday unless Accelerator was fully depressed.

Hooked it up to Nanocom and discovered only one Engine Code of P1204 which seems to be
"P1204 Injector 4 Open Circuit or Ground Short Fault"

So I had a look at HT Leads/Connections to Injector 4 (Cylinder 4) and checked for issues but seemed ok.

Further to this I hooked up my LPG Software (as the Injector Loom has the Split Connections for Injected LPG Setup) and it wasn't reading correct signals from this Injector. Pressed Firmly on the connector again and it started reading ok, idled better and ran ok.. but sure enough the "Shudders" happened after stopping again and a bit of extended driving.

My prognosis seems to be an issue with Injector staying on/open and allowing Fuel into the Cylinder, which is obviously why it's difficult to start/run initially but then drives ok afterwards. Does this seem consistent to your experiences?

My main question is whether this is likely to be a "Faulty Injector" Issue or "Faulty Wiring" Issue.

N.B: When I first start the car in the morning it is very hard to start and appears the Cylinder is flooded again....

Any Assistance/Advise appreciated.

[RR P38]

Sounds like more than one cylinder to cause such an issue.
Choke fault?
Stepper motor?

[bee utey]

After a few dud LPG patch looms I refuse to ever use them again. They are not well made. I solder and heat shrink the injector cuts directly to the main harness. Only OEM plugs connect to the injectors. This reduces wiring length and messy bunches of cables too.

Look for pins in the patch loom injector plugs falling out of their places by pulling back the heatshrink around the plug.

[BusinessConnected]

bee utey: I think that's what they have done... I'll begin having a closer look at this tomorrow.

RR P38: Once the Car is "Started" it runs fine... it's actually pretty hard to tell it's not fueling or running correctly on 1 Cylinder because it's only the 1 (I think)....

[RR P38]

Do you have an infrared temperature gun or access to one? I have a $10 hobby one its pretty handy for things like this reads up to 240C.

You could look at the exhaust temps at the headers.
Pull spark plug leads one at a time.
Disconnect the power to injectors one at a time.

Im sure you will get some other ideas from people.

[poleonpom]

Sounds like yours is coming out in sympathy for mine! ;)

One cylinder out shouldn't stop the car from starting - it would be missing on one cylinder and lumpy, but should start up with no other issue.

".....it wasn't reading correct signals from this Injector. Pressed Firmly on the connector again and it started reading ok, idled better and ran ok.. but sure enough the "Shudders" happened after stopping again and a bit of extended driving" - per description it seems connected to the wiring, perhaps the earth? seems to me it could be a loss of signal from the injectors that is affecting the whole car on.

Bit out of my depth on this one, but from your description I'd be thinking wiring.

[BusinessConnected]

When I say it doesn't start... it will start eventually (after perhaps a sustained 10-12 seconds of attempting to start).

I believe it's wiring myself... time to have a look at some of the "loom" connections.

[Rupert Prior]

slow to start can be many things, but a curly one and hard to find is a cam sensor to crank sensor miss-match. the engine takes a while to work out which stroke it is on before it can start. this is a fairly rare fault though.

[bee utey]

Do you have a way of forcing a gas start? Many systems have a method where you wait for the gauge lights to go out, then hold down the button and crank until it fires and runs on gas. I had a bloke with a D2 on injected gas, his fuel pump would leak down its pressure after about 1/2 hour and take ages to start on petrol. By forcing a gas start it started almost straight away and the petrol pump could fill the fuel rail at its leisure. Eventually he needed a new pump.

[poleonpom]

H how did you go? J

[BusinessConnected]

It's been a little bit bizarre recently... It seems to have been running fine on Petrol with no Hard Starting Issues this week... but having issues running on Gas.

It's taken back seat to the Lexus LS400 I've been getting going again... For your benefit J it was a Disintegrated Distributor Rotor that was causing our issues... Not Blocked Cat Convertors...

I'll be looking more at the Range Rover this week... However it's sort of on the Back Burner because the Panel Shop is getting to repair some accident damage in the next couple of weeks.