95 v8 not running right

[redjohnlx]

hi all,

long time reader first time poster.

anyway, i have a 95 v8 discovery duel fuel and its not running right.

it stopped starting on gas a week ago but would still run if it was started on petrol and switched to gas. now it sometimes does sometimes doesnt.

also the engine revs very high. on start up (petrol) it will go to 1900rpm cold. then settle down to about 1000rpm when warmed up. what causes the high idling.

the engine also doesnt decellerate properly. ie, when you are rolling to a stop the revs will jump higher and then settle down to about 1000rpm,

which sensors affect these characteristics, i have cleaned the MAF and it helped a bit but not enough.

what should i check next?

cheers
john

[roverspec]

Hi there is a few thing you can check.

1. check your timing and the vacum advance
2. Clean the vac T-Piece near the plenum chamber
3. The absolute last thing is to check the stepper motor, it is very rare we have never come across a faulty stepper motor yet.
4. You can get the air mass meter tested it could be breaking down.

Good luck

carla

[roverv8]

hi all,

long time reader first time poster.

anyway, i have a 95 v8 discovery duel fuel and its not running right.

it stopped starting on gas a week ago but would still run if it was started on petrol and switched to gas. now it sometimes does sometimes doesnt.

also the engine revs very high. on start up (petrol) it will go to 1900rpm cold. then settle down to about 1000rpm when warmed up. what causes the high idling.

the engine also doesnt decellerate properly. ie, when you are rolling to a stop the revs will jump higher and then settle down to about 1000rpm,

which sensors affect these characteristics, i have cleaned the MAF and it helped a bit but not enough.

what should i check next?

cheers
john

Given your vehicle is not running good on either fuel,
I'd start with a basic tune -up.
New plugs & leads, clean the rotor button and dizzy cap, set the timing.

Basic LPG systems don't really use the EFI sensors to run,
It simply just delivers gas into the plentium and the engine sucks it in and runs. (unless you have fancy gas injection system)
So with a tune it should run fine on LPG, unless you have a problem with the converter or something, then it should go to an LPG specialist to sort it out.

If at this stage it's running well on LPG but crap on fuel, it's really a process of elimation.
the MAF, TPS, Coolant temp sensor back to the ECU,
cleaning the t-piece Carla mentioned

I had a similar problem when starting on petrol with the high idleing at startup, also it wouldn't rev past about 1400rpm,
it turned out to be the MAF, but yours could be different,
it's a matter of going through it all.
Hope this helps
Luke

[justinc]

hi all,

long time reader first time poster.

anyway, i have a 95 v8 discovery duel fuel and its not running right.

it stopped starting on gas a week ago but would still run if it was started on petrol and switched to gas. now it sometimes does sometimes doesnt.

also the engine revs very high. on start up (petrol) it will go to 1900rpm cold. then settle down to about 1000rpm when warmed up. what causes the high idling.

the engine also doesnt decellerate properly. ie, when you are rolling to a stop the revs will jump higher and then settle down to about 1000rpm,

which sensors affect these characteristics, i have cleaned the MAF and it helped a bit but not enough.

what should i check next?

cheers
john

Most likely the TPS is out of adjustment/ faulty, check the voltage across the switch, throttle at rest, ignition on. Should be 320mV. If it is in fault mode, it will read a steady 500mV, and this is the cause of high idle. The 1994 on 3.9's have different plugs and wiring colours to the early ones, IIRC the wires to check are the 2 outer ones, in the early RRC and D1 with the round plug for the TPS, you check the voltage between the red and green wires.
If I remember tomorrow I'll post the correct wire colours up for you to check, or you can give me a call at work on (03) 6229 1102 and I'll take a squiz straight away.:)
JC

[LOVEMYRANGIE]

Or try this http://www.aulro.com/afvb/1092934-post12.html

Cheers

Andrew

[redjohnlx]

thanks for all the info guys. the car has already had most things replaced (dist. cap/leads/plugs etc) it has been a problem child in the past and normally every 3 or 4 months something tends to go wrong.

thanks for the link, i'll try that tomorrow.

cheers
john

[Waxenwane]

Ahh the beauty of Megasquirt, just ask the ECU to Calibrate and press the pedal:D

[redjohnlx]

ok, i have checked the MAF, TPS and engine coolent temp sensor at the front of the inlet manifold , and they all seem to be functioning ok.

does anyone know a good Land rover mechanic in sydney?

cheers
john

[redjohnlx]

anyone?

[PhilipA]

You could try Graeme Cooper, Bruce Davis, A&R automotive

A & R Automotive Brookvale: Mechanic & car service businesses (http://www.mechanicfinder.com.au/brookvale-mechanic/a-r-automotive.html)

Range Rover, Discovery, Defender & Freelander parts-supply and expert service from Graeme Cooper Automotive - Home (http://www.graemecooper.com.au/)

Davis Performance Landys
Amaroo Park Complex
233 Annangrove Road
Annangrove NSW 2156

Ph: 9679 1978
Fax: 9679 1993
Regards Philip A

[roverv8]

ok, i have checked the MAF, TPS and engine coolent temp sensor at the front of the inlet manifold , and they all seem to be functioning ok.

does anyone know a good Land rover mechanic in sydney?

cheers
john

What did you do to check the MAF,
I set the voltage on my MAF, also cleaned it,
the 2 elements looked ok, but still had a problem.
I took a punt and got a second hand one, came off a car thats only been run on petrol, and presto, problem solved.
Backfiring from LPG stuffs them up.

Is there anyone close by to you with a known working MAF you could try,
you can swap them over in less than a minute.

[Flybouy75]

Have you tried the stepper motor to resolve the high idle issue?........ Mine would behave the same, high idle and would not drop down, pulled the stepper out, cleaned it, put it back in tighten the 3 bolt's on the rear of the steeper motor housing, hey presto, a cheap fix.... for once!


Good luck with it.......