Author Topic: mtdi running issue  (Read 4310 times)

July 17, 2011, 11:11:01 am

monkey magic

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mtdi running issue
« on: July 17, 2011, 11:11:01 am »
Hi all,

just had to swap engines in my vanagon, and cannot get the engine to run happily.

I had an AHU with a landrover 200tdi pump on, pump was part serviced (a seal had failed), and i have done several thousand miles on this setup without issues. I killed the engine with oil issues, and had chance at a 1Z unit. The 1Z was in a car so i got to drive it etc, was happy with the engine, ran well.

So, once all the important bits were swapped to the 1Z, new cambelt kit on, i put it in the van and ran it.

With no timing dial adapter (my mate lost it : ( and i forgot to mark the pump/bracket position) i planned on timing by ear, at least to get started. What I found was it fired up first time where i set the pump, but tickover was high, and power was low. I drove it like this for 5 miles. On stopping and checking the engine, I found that the cylinder head seemed MUCH hotter than I expected, and so i limped back to the workshop.

I tried adjusting timing manually, but the high revving at tickover didnt change at either end of the adjustment range. I thought this high revving and extra heat was a symptom of too much advance, but altering static timing didnt affect this one bit.

Is it possible I just have the pump 180 degrees out? I have read that they will run like this. The 1Z was a happy engine whilst in its donor car, and the landrover pump was happy when bolted to the AHU.

Im going to go and double check crude (ie to the tooth) cam and pump timing, and hope this is where the solution lies. It confuses me that the engine can rev high with no mods to the pump since removing it,

confused.. Anybody got any thoughts/ideas?...

Monkey Phil... ; )


mTDi syncro

Reply #1July 18, 2011, 04:39:03 am

svenakela

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Re: mtdi running issue
« Reply #1 on: July 18, 2011, 04:39:03 am »
I did put my pump -180 and it didn't run at all.

Do you have any digital calliper? That's what I use and it works really well. I extend the depth measure stick and and fix the calliper by the vacuum pump with a piece of tape. :)


Reply #2July 18, 2011, 05:08:49 am

monkey magic

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Re: mtdi running issue
« Reply #2 on: July 18, 2011, 05:08:49 am »
Hi Svenakela,

like your style! Couldn't do that on mine, its very crowded in that area. Im had to buy another adapter, so Im just waiting for it to arrive in the post.

The plot thickens anyway, : I did get this unit running well yesterday, the problem is kind of solved, but the mystery is not.

The cam was timed properly to the crank, and the IP pulley was in the correct place (at least the correct cylinder is firing at approx the correct time).

All we did in the end was shift the pump to the middle of its adjustment (which didnt alter high revving tickover), and then back the idle stop off, a LOT (several turns)!!

I didnt like doing this, as I still dont understand why it was needed. The same pump on the AHU unit, tickover was just right, with no adjustment needed (the pump is not modified in any way).

The only differences between the two engines/setups I can think of are:

1) I swapped over the TDI delivery valves, I hadnt done this 1st time around
2) The current engine has different breaking pressures on the injectors (190 compared to 220/300 I believe)

Could either of these things affect idle speed drastically? The engine did 40 miles last night, and while it was slightly down on power compared to the previous engine (fine tuning the timing will no doubt fix this), it ran without issue..

Anybody got any ideas on this?
mTDi syncro

Reply #3July 18, 2011, 09:16:50 am

theman53

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Re: mtdi running issue
« Reply #3 on: July 18, 2011, 09:16:50 am »
THe breaking pressure alone will change the timing value and probably the idle as well. The pump doesn't have to get to the higher pressure to open the injector and inject fuel so it is like advancing the pump you used to have in there. The delivery valves may also have the same affect/effect...never was good at english :D

Reply #4July 18, 2011, 02:42:10 pm

svenakela

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Re: mtdi running issue
« Reply #4 on: July 18, 2011, 02:42:10 pm »
i agree with theman53, different injectors - different setup. :)

Reply #5July 18, 2011, 06:17:30 pm

snakemaster

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Re: mtdi running issue
« Reply #5 on: July 18, 2011, 06:17:30 pm »
i agree with theman53, different injectors - different setup. :)
i will thrd that, comming down to 190bar will put the idle up , change your injectors
Glenmorangie  single highland malt

Reply #6July 18, 2011, 06:38:16 pm

monkey magic

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Re: mtdi running issue
« Reply #6 on: July 18, 2011, 06:38:16 pm »
Cheers for the replies guys. i kind of had the same theory myself, but the thing that contradicts is: the fast idle didnt alter when i manually advanced and retarded the pump, so if the advance from the lower breaking injector firing early is enough to affect idle, then so should advancing timing manually. I agree though, I can see how the lower breaking injectors would interact somehow with the pump and cause random issues like this.

Well, i just happen to have a set of 110bhp injectors (afn?), serviced and ready to go. I'm going to time up the pump on wednesday when the adapter arrives, and see what happens then. If all is well, ill put the 110 injectors on and see what difference it makes.

I got to spend 5 minutes this evening with the guy who serviced the pump when i 1st got it. He said that one of the fuel screws (not sure which is which, the one with a collar on to limit adjustment) looks to be further in than it should be, but its exactly where he set it when he serviced the pump. He also thinks it could be a contamination issue, but it still doesnt explain why it happened EXACTLY the same time as the engine swap. He has advised me to back this screw out and see if it lowers the idle.. Im not doing anything until timing is properly set and these injectors are on though.

Cheers again guys, hopefully you're all bang on the money, and these injectors will sort it out. I'll post back with updates : )

Monkey Phil  ;D
mTDi syncro

 

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