Engine vibration 1HD-T

[Shayne]

To a point , compressed air allows a good burn but when you decelerate there is limited amount of air and fuel can't burn without air . Its all just uneducated theory from me but i can picture it , too much fuel in the first 3 or 4 cylinders has enough air to burn clean , but 5 and 6 are struggling for air and so flood .

I could be way off the mark but these are simple and cheap things to check before you spend any more hard earned .

 

[StarCruiser]

Wouldn't I get black smoke though if there were too much fuel? I think the bottom line is that there must be an imbalance in one cylinder. I see what you're saying but unlike a petrol, the fuel mix is in the cylinder and most of the time will run air rich (I.e lean) unless under more load than the fuel air mix can overcome so excess fuel is then injected due to less air being sucked into the cylinders. But we're talking the other way round. Idle, with a tiniest squirt of fuel being sent in and a cylinder full of air, admittedly under natural aspiration. It's actually worse with a brand new K&N filter in it. I think it's too little fuel or too short a squirt for one of the cylinders, perhaps some muck got in the pump somehow due to me forgetting to change the fuel filter?

 

[Shayne]

I don't think your fuel is set too high . Your pump is manual but it also has an auto function which increases fuel without any input from you to compensate for boost pressure . More air more fuel , its timed mechanically to keep the fuel air mix right on boost off boost idle or racing . I think to auto bit is staying on and adding more fuel when it shouldn't and messing up the mix .

 

[StarCruiser]

Its certainly worth checking Shayne. And shouldn't be too tricky with a syringe on the tubing at the intake connection.

 

[Shayne]

I can't hear this but he is at where i would be looking for a fault https://www.youtube.com/watch?v=edlbQh3s5jU

 

[StarCruiser]

Thanks for that Shayne, that should come in handy, especially once this is sorted and I can fit my intercooler. [emoji83]

 

[frank rabbets]

I wonder if your vibration is inlet noise. The 24valve ones suffered from this so badly that Toyo added a resonance box on top of the filter air housing o later models. Mine was an early one and I managed to get a later top and it made a big difference. I've since added sound deadening to the out side of the box and it's even better. The vibration was evident on releasing the throttle from a very high rpm. It was worse in neutral. If I revved it to 4000 rpm then released the throttle there was a terrible vibration/noise down to idle. All the early models suffered. I don't know if the 12 valve suffered but it might be worth investigating whether or not you have a non standard inlet tract. My vibration/noise was just resonance in the inlet chamber but I would never have guessed . A friend of mine came for a ride in it and I took it up to 4000 rpm in 1st gear and on changing to second gear =vibration/noise he said " you have a lot of inlet resonance". I would never have thought it was just air. It made the whole car vibrate. I swopped box tops with Jon's later model to double check and bingo. Mine drove him mad lol.

 

[StarCruiser]

I know what you mean Frank and thanks for the thought but it's 100% not that as its resonant frequency is around 900 rpm.

 

[tenzhushoten]

mine had the same problem but I fixed it !

 

[StarCruiser]

mine had the same problem but I fixed it !

Hi and welcome, that's great to hear, may I ask how you fixed it please?

 

[jamesfickackerly]

I think there is a problem with these engines. It tends to vibrate a lot. Mine had the same issue.

 

[Dave2000]

The 1HD-T does have a problem with vibration and what seems like a misfire at idle or just off idle as the injectors wear, long story coming up!

There are couple of 80's here that had a similar problem, but it only rears it's ugly head when the engine AND the weather is hot. That is they run perfect most of the year, as the temps get hotter then a short run down the motorway can set off this weird idle or low speed running. If it was a petrol engine you would have sworn it had an intake manifold air leak. We checked valve clearances hot and cold, new fuel filter, new pipes, new plunger primer head, injection timing perfect, by my calculations and the guy at the diesel specialist all to no avail. Eventually we narrowed it down to the fuel temperature, this was more by luck than judgement, it was running bad and the tank was low, this was on purpose so I could 'hoover' the tank bottom to get rid of any rust or sediment in there, a low tank makes it easier to see the bottom. There was a couple of gallons in there at a guess and when finished and within around 20 - 30 minutes of idling the roughness came back, we were about to call it a day and just popped down the garage and filled up with fuel. Drove out of the garage and a couple of miles down the road and pausing at a roundabout, the car was running perfect. So the following day a good hard run up the motorway, back to the garage with the poor idle and more or less full tank, we put a can of cold diesel on the roof of one of the cars (an auto), and then simply swapped the supply from the tank to the roof container. Within seconds of the engine getting the cooler fuel the car ran better, another few minutes and the idle was as near as dammit perfect in or out of gear. Swapped back the tank supply and within a minute or so the idle became bad again. We did try a temporary lift pump thinking the gravity feed was helping but no. After talking to a guy at the diesel pump specialist, he reckoned the injectors need an overhaul, we were losing something in the translation but gather it is to do with fuel density which changes with temperature, and it affects the size of the fuel droplets during atomisation. He said normally it is no big deal and we don't notice any difference hot or cold, as the injectors get worse the problem becomes more frequent. He said it is pointless doing the pump if the injectors had done more than 180,000kms, the car we were showing him had IIRC circa 180,000 + miles. There was something about not being able to just replace the jets or nozzles and they were way more expensive than my Land Rover I had at the time, the owner left it and decided to sell the car. I did check the fuel pick up and it was good, and we did run a couple of bottles of injector cleaner through the tank, still no change. We asked about the high pressure cleaning that can be done in situ and he reckoned it would not work. We had to trust that because the owner had thrown enough money at it and was not going any further. I have not seen that car since it was sold, another that was sold that had similar issues and I do know where it is, it is living in a colder climate and the guy has had no problems so.............?

regards

Dave

 

[StarCruiser]

That's all most interesting Dave and makes perfect sense to me. I.E with thicker fluid the pump seals better and the injectors etc get the pressures they need to perform as they should.

I've had the injectors reconditioned with new Denso parts. The test before showed poor injectors with one leaking badly. I was meticulous in putting them back not to get anything dirty though I didn't flush the pipes, pump or anything else for that matter. I can only assume that the injectors are still fine and within spec.

Compression comes up as 500psi +- 20psi

Nothing is loose or degraded on engine mountings or dampers.

The only thing I can think of is that the pump has a slight problem on one cylinder, perhaps a leaky delivery valve.

Symptoms are worse when the engine is cold and just up off idle. Cold weather makes it worse and has on the coldest morning shown some white smoke from the exhaust where normally there is none.

The video below is more for the audio really. Just after start, you can, if you listen carefully, hear what sounds like a regular knock which in my mind is one cylinder out of the 6. BEBs have been changed and this fault was present before and after, unchanged.

https://vimeo.com/162047394

By process of elimination, and by the fact that nothing I've done has altered the problem for better or worse, and that allowing better airflow (K&N filter) seemed to make it slightly worse, my thoughts are with a lower delivery of fuel into one cylinder. I suspect a delivery valve on the pump to be leaking allowing the standing pressure in the injector pipe to drop after each injection, something the subsequent injection has to make up before the pressure appears at the injector, causing less than the intended measure of fuel to be delivered.

My next planned move, when I get the chance, is to remove the pump for test and potential rebuild. I don't like condemning anything before finding it is at fault so a test should hopefully show up whether or not the pump has a problem. Getting a test done on a mechanical pump these days is getting more and more difficult (or so in told).

Hopefully better weather is coming so it may be time to bite the bullet soon and heave the pump out for test.

 

[Ian Chuter]

My next planned move, when I get the chance, is to remove the pump for test and potential rebuild. I don't like condemning anything before finding it is at fault so a test should hopefully show up whether or not the pump has a problem. Getting a test done on a mechanical pump these days is getting more and more difficult (or so in told).

Hopefully better weather is coming so it may be time to bite the bullet soon and heave the pump out for test.

Same place as you had your injectors done will do your pump Richard
Ian

 

[StarCruiser]

Yes, I thought about them. Thing is, first thing they said was 'of course it's not going to be the pump' which I suppose given my luck should have had me pulling the pump off next day and sending it to them. [emoji4]

 

[chapel gate]

Hi and welcome, that's great to hear, may I ask how you fixed it please?

I think he had a new engine from that place he and his mate james work at..

 

[StarCruiser]

I did wonder if that might be the case. A bit like fixing a non runner by buying a new car you mean? [emoji23]

 

[frank rabbets]

Ring the bloke at RVS Swindon for a chat. I've talked to him many times and he's very helpful.

 

[StarCruiser]

Thanks Frank, I may well do that.

 

[Shayne]

An hour and 20 minutes away that RSV Swindon place from me I wonder how long it would take then to overhaul my pump and injectors , check valve clearances and whatever else , just for longevity's sake . Would it be worth the cost at 130k miles ?