Prado won't go!

Submitted: Thursday, Mar 22, 2012 at 19:48
ThreadID: 92715 Views:4681 Replies:7 FollowUps:10
This Thread has been Archived
Hello fellow members.
Just thought i'd post an update re my Prado problems. About a month or 2 ago I posted a thread relating to the fact that my Prado lacks power when running on ULP. (It has gas and seems to run well on gas.) It has recently started to cut out altogether when switching from ULP to LPG, and once stopped working when idling on ULP. After cranking it over for about 5 minutes it finally got going again. I have changed the fuel filter, cleaned the MAF sensor, changed the fuel pump on the unleaded tank, but still not difference.
I am about to have the injectors cleaned and have decided to remove the gas altogether. Considering gas is now 90 odd cents a litre, can't see the benefits anymore and i'm also sick of the poor touring range.
I'm not sure if anyone has got any info to assist me or not, but thought it may interest other members, or a member may have had the same issues. The car has been well looked after, was converted to gas at 95k and has now done 190k. It doesn't leak or use any water or oil. It pulls a 2004 model Kimberley Kamper.

Cheers, Grant.
Back Expand Un-Read 0 Moderator

Reply By: 120scruiser (NSW) - Thursday, Mar 22, 2012 at 20:13

Thursday, Mar 22, 2012 at 20:13
Hi Grant
There are 2 problems when cars are converted to LPG.
When they aren't run on petrol often enough the fuel injectors will sieze, block or play up. An off car ultrasonic bath should fix them or at least pick up a problem with one or more when they are flow and pressure tested.
The other problem is the fuel pump stuffs up. Depending on how old the system is, some have the fuel pumps run all the time and others tap into the fuel pump system to cut it out when LPG is running. The ones that run all the time require about 1/4 tank of petrol to be in the tank to prevent the fuel pump from over heating.
By the sounds of it that it starts,, the fuel pump is working so I would try having the injectors done and see how it is. Probably whilst the injectors are being done have a fuel pressure test conducted.
Scott
AnswerID: 481117

Reply By: Member - Tour Boy ( Bundy QLD) - Thursday, Mar 22, 2012 at 20:17

Thursday, Mar 22, 2012 at 20:17
Hi Grant,
Have you confirmed that the MAF is actually working? Has the gas ever backfired?
Find someone that will let you borrow their MAF to see if it will run /idle properly. If it isn't working properly and giving false readings the computer may shut off the fuel but it won't affect the lpg.
Cheers,
Dave
2010 Isuzu FTS800 Expedition camper
2015 Fortuner
Had 72 cruisers in my time

Lifetime Member
My Profile  My Blog  My Position  Send Message

AnswerID: 481120

Follow Up By: Member - Grant- Thursday, Mar 22, 2012 at 20:37

Thursday, Mar 22, 2012 at 20:37
Hello Dave.
Yeh, I remember your input last time. I changed the fuel pump, which I think was one of your suggestions last time. It's actually gotten worse since then. I'll try and find someone with the same car and have a go at that. Yes the car has backfired a few times, probably not for a year or so now though. I've only really noticed it in the last few months.

Cheers for the input.
0
FollowupID: 756515

Follow Up By: Member - Tour Boy ( Bundy QLD) - Friday, Mar 23, 2012 at 07:05

Friday, Mar 23, 2012 at 07:05
Hi Grant,
Backfire will kill an maf. It could also explain the lack of power. If it doesn't think there is enough air going past the sensors the computer won't allow the fuel to be delivered.
Backfire is usually caused by worn plugs or leads, up keep of these items is crucial to prevent backfires.
At least by the end of this you won't have to worry for another 10 years.
Cheers,
Dave
2010 Isuzu FTS800 Expedition camper
2015 Fortuner
Had 72 cruisers in my time

Lifetime Member
My Profile  My Blog  My Position  Send Message

0
FollowupID: 756538

Follow Up By: Member - Grant- Friday, Mar 23, 2012 at 09:16

Friday, Mar 23, 2012 at 09:16
Yep, thanks Dave.
I'll keep you posted. At least I'm getting to know my car inside out I suppose.

PS, I still wouldn't dare to take my family out into the bush in anything but a TOJO!
0
FollowupID: 756555

Reply By: dindy - Friday, Mar 23, 2012 at 13:11

Friday, Mar 23, 2012 at 13:11
I have been running a 1984 4.5 litre petrol landcruiser on gas for the last ten years. It has a vapour system, I have over that period of time all of the issues others have related here. There is another possibility at that you need to consider and that is the gas converter may be faulty. It may be over fuelling or starving the motor. The symptoms you have described in may indicate this situation. The only way that you can check this for sure is to take the vehicle to a gas specialist who can test the system and converter.
AnswerID: 481188

Follow Up By: Member - Grant- Friday, Mar 23, 2012 at 17:19

Friday, Mar 23, 2012 at 17:19
Hello Dindy.

Thanks for your feedback. There will be nothing to test on the gas system however, because its being removed.

Cheers
0
FollowupID: 756581

Reply By: GT Campers - Friday, Mar 23, 2012 at 13:35

Friday, Mar 23, 2012 at 13:35
not nuch use to you until your problem is fixed, but as you have an old-school system that doens't start the engine on petrol, you should run 1/4 tank ULP (or 2-300km) through your car AT LEAST once per month to keep fuel fresh and injectors happy
AnswerID: 481190

Follow Up By: Member - Grant- Friday, Mar 23, 2012 at 17:17

Friday, Mar 23, 2012 at 17:17
Hello mate. It's not really an old gas system. It's 3 years old. It automatically starts on ULP and runs regularly on ULP.
The brand is IMPCO or IMCO or something similar.
0
FollowupID: 756580

Follow Up By: GT Campers - Friday, Mar 23, 2012 at 18:39

Friday, Mar 23, 2012 at 18:39
hey sorry my mistake, someone mentioned backfiring - I assumed yours, and non-sequential feed as the new-tech systems can't backfire.

I can imagine your frustration - I also have the electronic multi-point sequential LPG on my Toyota V6 and it is sensational. I would be getting things checked out by the installer - AFAIK there is a diagnostics protocol that should help pinpoint the problem
0
FollowupID: 756586

Follow Up By: Member - Tour Boy ( Bundy QLD) - Friday, Mar 23, 2012 at 20:21

Friday, Mar 23, 2012 at 20:21
Hi Dindy and GT Campers,
Grant isn't having problems with the gas he is removing it for other reasons.
The problem is with the ULP not running well and sometimes not running at all.
Cheers,
Dave
2010 Isuzu FTS800 Expedition camper
2015 Fortuner
Had 72 cruisers in my time

Lifetime Member
My Profile  My Blog  My Position  Send Message

0
FollowupID: 756590

Reply By: olcoolone - Saturday, Mar 24, 2012 at 08:19

Saturday, Mar 24, 2012 at 08:19
Have you thought about getting professional help with the problem..... we see DIYers come into our workshop with a list of things they have changed trying to fix a problem...... only to find out it was something simple.

Had a guy who had a car that would not run uphills.... from advice from friends and forums he changed the fuel pump (drop tank to do 5+ hours), coil pack, sparkplugs and leads only for use to find out it was a dented fuel line under the car.

You might find with the right help and professional advice it might be a simple fix.

AnswerID: 481226

Follow Up By: Member - Grant- Monday, Mar 26, 2012 at 19:54

Monday, Mar 26, 2012 at 19:54
Hello Olcoolone.

Yes, very good point that. The car now won't start so it's in for professional help tomorrow. First thing, the gas is being removed.
That's the price you get for trying to be a cheap skate I suppose, but yes, probably just should have done that in the first place, and yes, it probably is an easy fix.

Cheers.
0
FollowupID: 756825

Reply By: Member - Paul B (WA) - Saturday, Mar 24, 2012 at 10:27

Saturday, Mar 24, 2012 at 10:27
Get rid of the gas and you will love your car again. It will have power up hills and towing again. It will go back to having a 1200km fuel range instead of 700km so you will be able to throw your Jerry cans away.

And best of all, all these annoying silly problems will just vanish. And if you're really lucky, having only done 100-odd thousand km on gas, you probably won't need a top end rebuild costing $6,500.

And when you've taken it all off, go and find the w@nker who installed it and shove it where the sun don't shine. You will feel totally liberated!

AnswerID: 481238

Follow Up By: GT Campers - Saturday, Mar 24, 2012 at 21:08

Saturday, Mar 24, 2012 at 21:08
Paul,
I've done 50,000km in 11 months
I see 20L/100km
and can do 170km/h


...all while towing on LPG :)

I reckon there might be an electrical problem that is interfering with (petrol) injector actuation, maybe in the switching/disabling circuit switched by the LPG ECU
0
FollowupID: 756655

Follow Up By: Member - Grant- Monday, Mar 26, 2012 at 19:59

Monday, Mar 26, 2012 at 19:59
Hello Paul and GT Campers.

The car actually won't start now, so it's going to a professional tomorrow. The gas is being removed and hopefully it will be an easy cheapish fix.

Thanks all for your replies, luv ExplorOz.
0
FollowupID: 756826

Reply By: Begaboy - Saturday, Mar 31, 2012 at 14:03

Saturday, Mar 31, 2012 at 14:03
our second 4bie is a prado on gas also - and now do not see a benifit at all - now with the price of LPG it costs the same to run the prado as it does my diesel patrol with additional expenses like leads , spark plugs ect

selling the prado soon and getting second diesel maybe a Terrican -- was great when LPg was 39 cpl now at 90 cpl + its not worth the hassle


AnswerID: 481976

Sponsored Links