Problems with 1HDT on SVO

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

I have some issues with a 1HDT on SVO.

It runs fine up to about 90kmh and then it loses power and won't rev any further. Switching back to dino in the sub tank makes a bit of an improvement but not much - it struggles to get past 100kmh. Even washing the SVO down to 50% with dino makes not much difference. If I turn the engine off on V100 the engine keeps running. I have to switch back to dino for a few minutes for the engine to stop. It has nowhere near as much power as the 1HZ that I used to have with an aftermarket turbo.

Here's what I know:

1. The SVO is fine. I've been using it in other vehicles with no probs
2. The engine is fine
3. The injectors are fine.

That leaves two options I can see - the IP and the turbo. The turbo has 340k on it

Comments?

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: Problems with 1HDT on SVO

I dont have any experience on 1HDT, but a fair bit on its older brother, the 1HZ with power issues. My first thought on your problem was fuel starvation, either through blockage in the fuel cut solenoid gauze (crap might be built up around the plunger o rings preventing the shutoff from occuring) or the rubber o rings have died and fallen apart, partly blocking the ports. If the fuel cut off plunger is ok, the power issues might be solvable with a pusher pump. I saw huge increase in drive ability of the 1HZ after fitting a pusher pump, as I couldn't stop it from pulling air in the line through the stock filter housing. a clear hose installed before the pump will tell you if you have air leaks. Now i know the Ihdt has a different fuel pump to the 1HZ, but I reckon it will still have a fuel cut off plunger.

Good luck.

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: Problems with 1HDT on SVO

Thanks for the repluy. If by pusher pump you mean a lift pump it already has one, and it makes no difference. Which probably means that the IP needs a rebuild.

Or I could give it to GTurbo, get them to replace the original turbo with a Bad Boy, and add an upgraded IP and intercooler.... Still doing the sums

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Problems with 1HDT on SVO

How about going to someone who knows these engines and have them diagnose the fault. They will know the common failures and be able to make suggestions or repair it if you want to go that way.
Throwing money at the IP or turbo is unlikely to find the fault as you will have disturbed the system significantly. It may fix the fault if you are lucku, defer the fault (comes back later) or not fix the fault and it is as bad as before.

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: Problems with 1HDT on SVO

How about going to someone who knows these engines and have them diagnose the fault. They will know the common failures and be able to make suggestions or repair it if you want to go that way.
Throwing money at the IP or turbo is unlikely to find the fault as you will have disturbed the system significantly. It may fix the fault if you are lucku, defer the fault (comes back later) or not fix the fault and it is as bad as before.

Good idea. Any suggestions?

[Alga Senior Member Find all posts View Profile Close Alga]

Re: Problems with 1HDT on SVO

Just purchased a hdj80r last week for a song and sold my old cruiser (678000klm). Am about to convert the hd to vo and would like to ask the following of Mark.

Are you using throw away inline filters, a secondary pump on the vo line from the tank, 12mm fuel lines from the tank and re plumbed your return line into the fuel line after the main filter. This way you always have hot fuel going into the iP. Used to have a turbo triton with the rotary pimp and had nothing but trouble until looped the return line

In the past have found leaving the return line to the tank, means hot oil getting in and effecting the oil

My 12HT engines tend to struggle without a secondary pump on the fuel line after the tank, as does just about all my vehicles, have found these turbo's need a constant big supply of fuel and any slow down makes them struggle.

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: Problems with 1HDT on SVO

Just purchased a hdj80r last week for a song and sold my old cruiser (678000klm). Am about to convert the hd to vo and would like to ask the following of Mark.

Are you using throw away inline filters, a secondary pump on the vo line from the tank, 12mm fuel lines from the tank and re plumbed your return line into the fuel line after the main filter.

1. Not using inline filters, but oil clarity isn't the issue
2. Yes there is a lift pump. But it doesn't make any difference.

I don't understand the bit about the return line, but can't see how fuel temperature is the issue. Once the oil enters the engine bay it'll heat up pretty quickly, particularly after it's gone through the filter.

But the bottom line is that I know there's something wrong with the IP anyway, as the car doesn't even run right on Dino.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Problems with 1HDT on SVO

Good idea. Any suggestions?

Mark,
Not having a Landcruiser, I cannot make any recommendations. Perhaps you may like to ask others in WA, who have a Toyota, and see who they would recommend.
Perhaps Tim may be able to advise.

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: Problems with 1HDT on SVO

Actually I was up talking to Graham at GTurbo yesterday. The turbo needs an upgrade anyway - the standard Toyo turbo is was too mild. T=He said that the issues with the IP may just be a tuning issue (I doubt it). So I'll get the turbo upgraded to a Bad Boy and then he'll have a go at tuning the IP accordingly. If the the pump does need a rebuild, then so be it

How do you construct a sig file? I couldn't see anything in the menu structure

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Problems with 1HDT on SVO

Mark.
Click on "Settings" (Top RHS of screen)
When window opens you will see a series of boxes down the LHS of screen. Go down to My Settings.
In there you can edit your profile, create / edit your signature, etc
Save when happy with your efforts.

[smithw Senior Member Find all posts View Profile Close smithw]

Re: Problems with 1HDT on SVO

Have you taken the injector pumps inlet banjo off and had a look down the hole? There is often a small metal gorse filter in there which gets blocked, sometimes they are inside the bolt, its very hard to see and you will have to hook it out with a with a wire.

[Johnnojack Senior Member Find all posts View Profile Close Johnnojack]

Re: Problems with 1HDT on SVO

Dr Mark there are several things which could happen with the IP which can reduce power output. First is blockage from WVO polymerising in the inlet to the pressure head, there is often a small piece of brass or stainless gauze at that point. Or there can on Toyotas be a small tube of gauze inside the port the stop solenoid screws into. Another thing which can happen is the regulating valve o rings can desintegrate causing loss of pump primary pressure and subsequently injection pressure. The high pressure piston can wear also reducing pressure and causing starting problems.
All these faults, by themselves or combined in various degrees will starve the engine of fuel. This can lead some people to blame the turbo as it fails to make as much boost. However any turbo needs exhaust pressure to make boost and if there is insufficient fuel there is less exhaust so less boost. QThe last thing you should do is change the turbo without getting the fuel right. A bigger turbo will possibly make it worse while the IP is underperforming as it needs more exhaust flow than the smaller standard one.
Have someone follow you and if the vehicle smokes (black) while you are flat out at 90ks then maybe there is a turbo problem, if no smoke there is a fuel problem. This will only apply if the injectors are good as you claim they are.

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: Problems with 1HDT on SVO

Have you taken the injector pumps inlet banjo off and had a look down the hole? There is often a small metal gorse filter in there which gets blocked, sometimes they are inside the bolt,[ATTACH=CONFIG]2256[/ATTACH] its very hard to see and you will have to hook it out with a with a wire.

Thanks for the tip - I'll have a look

[Dr Mark Senior Member Find all posts View Profile Close Dr Mark]

Re: Problems with 1HDT on SVO

Have you taken the injector pumps inlet banjo off and had a look down the hole? There is often a small metal gorse filter in there which gets blocked, sometimes they are inside the bolt,[ATTACH=CONFIG]2256[/ATTACH] its very hard to see and you will have to hook it out with a with a wire.

No filter in mine.

It looks like I'll just get the IP rebuilt as part of the turbo upgrade. I tried the trick with flooring it and there's no smoke coming out. Definately a fuel starvation issue.

Main reason I'm going for a turbo upgrade is the mild nature of the 1HDT - only 870kw at the rear wheels. With a GTurbo Bad Boy on it I can get 120-160kW depending on tune. They will fix that IP as part of the upgrade

[Johnnojack Senior Member Find all posts View Profile Close Johnnojack]

Re: Problems with 1HDT on SVO

Only 870kw at the rear wheels! Pathetic. Sounds like you are determined to rev her up a bit regardless, money must be burning a hole in your pocket Dr Mark. Good luck with it.