Isuzu Engine Astra MK3

[andyamos]

Hi guys

I am sorry this is again repeating LOTS of already answered questions, but I am in a little state of confusion. I have tried the links on here and read all I can about the white polo etc, but am not sure of the exact process. I have recently bought my dad a 1.7Td Isuzu engined astra and to be honest there is more power being dragged along by a pet dog than in this thing. I doubt it would pull the skin of a rice pudding as the saying goes....

Basically I am questioning the Turbo or at least whether or not the thing is indeed working. Chances are it is and because I am comparing it to the C20Let Cally I am driving, it is going to appear somewhat underpowered. My question really is:

Does anyone have a link for the guide of how to increase power of these engines... I have tried the obvious ones but the pics are down and am not sure of what I am supposed to be looking / searching for. I had a good look and couldnt see the 4 10mm bolts described anywhere. Do I need to take the inlet manifold off to get to it?

There were LOTS of problems with the car, from a non working Temp gauge to a melted alternator-starter cable. I have repaired all that and found a split in the turbo to intercooler pipe. That too has now been repaired, but the car just doesnt seem to pull very hard at all.

If anyone has any idea of a site that still hosts the pics as well as instructions, I will be MOST grateful.

Cheers guys )

[ajg1974]

I used to have a Corsa 1.5td that one of my mates had increased the boost on (I think thats what he did anyway) by undoing a lock nut on the waste gate and turning the nut underneath by a couple of turns (or maybe less!) it defo went quicker, not sure what effect it had on its long term reliablility though cos I only had it just over a year!

[DutchNovaDiesel]

Taking the inlet manifold off is the best way to get to it,
the guide on cs says to cut the polo ring, but there is no need for that. (i.e. reversible mod)
taking it off however isn't as easy as it seems, it's held on by two 12mm nuts and five 8mm bolts,
the bolts are the problem:

as you can see they are not regular bolts, i bought a socket for them, was
a stahlwille item part no. 50 size 8 (12 edges...dunno the proper name)

Here you can see that there isn't much working space between manifold and pump.
(this used to be the big flat manifold which also houses the filter)
the safety valve can also be seen sticking out of the manifold, not all isuzu's have this btw.


From this point, make sure you're working as clean as possible,
you don't want any dirt getting in the pump, onto the plunger etc.

Once the manifold is off you can easily see the four 10mm bolts, undo the four bolts,
slightly bend the fuel return pipe and gently take off the cover

Then you'll see the rubber diaphram: DO NOT rip it out, firstly mark the nut on top of the diaphram
(turning it = adjusting it, so you'll need to know it's original position),
then take it out (you may need to turn it a little to get it out)


The pump without plunger & diaphram:

The plunger with diaphram:

the white polo, i knew it was in there somewhere !
(note: the cone at the end of the plunger is eccentric, therefore if u turn it, you're adjusting it...
look at it closely and you can see the markings on the cone made by the follower in the pump )

now, take it off:

Hammering the dimple out of the cover will make the plunger come up higher
and only affects the smoking when it's idling / not boosting (not really necessary i'd say)

Now, put the plunger back in it's original position (again: you may need to turn it to put it in),
make sure the edges of the rubber diaphram are in the groove,
then put the cover back on, push the fuel pipe back and tighten the four bolts.

The mysterious antitamper cover....can easily be removed with a big flat screwdriver:
just put it between the pump and the base of the cover and turn it and it should come off
If not, use all means necessary to get it off !

Underneath it is a 13mm lock nut and the max fuel screw, mark it's original position,
then undo the nut and turn the screw, how much is up to you: 1/2 a turn is a lot and
you might want to adjust it to your own need.

If u start the car it will idle a lot higher (remember turning the max fuel screw)
therefore you need to adjust both the cold and hot idle screws: (blue for cold, red for hot):
these also have a lock nut on them (8 or 10 mm spanner will help you out)


Turning up the boost, using a bleedvalve or MBC.
Extra parts needed: 4mm boost hose (or fuel hose, which is also very strong),
clips or hose clamps AND a boost gauge with parts to install it (t-piece and pipe)

Look at the turbo and source the pipe that goes to the actuator (sits on the back of the turbo),
use some pliers to undo the clips and take off the hose, depending on the car
and turbo you could either cut this hose in half and put the bleedvalve/mbc inbetween
or use some extra boosthose to fit it (that's what i did):

don't know which way to put it? it's from turbo->bleedvalve/mbc->actuator

How much boost ? Can't tell you; in original form the nova's/corsa's run 0.68 bar and the astra/cav runs 0.8 bar...
i.e. you're on your own here (and i take no responsibility if something goes BANG!)

If u have a safety valve, then +/- 1.1 bar is as high as you can go, want to go up, mod it !
Put the valve in a vice (upsidedown), then drill into the center until the center comes off:
(center is on the right), then you can take the valve apart:
I welded a big nut (14 or 16mm...dunno exactly) in the valve and removed the ring on top:

Removing ring on top:


Cheers, J

[TDNova]

J you are a legond how far is your car on now is it near finished? i still havent got another nova/corsa to do yet but i will one day. the police think i shouldent drive anymore iether so that kind of stands in the way a bit.
i do miss my turbo diesel tho!

[vxlgsi]

cool, my bro will need this info

[andynova1389]

what happens if you dont take this white ring off, but just turn the max fuel screw and turn up the boost????

[DutchNovaDiesel]

That will also spice it up a little...but not as much as you'd like
i.e. it's worth the effort, inlet gasket should be around £3-4, socket cost me £6,-

Cheers, J

P.S. cars not even near finished, rebuilding engine, going to put side windows in again (it's a van) and have a lot of plans to carry out

Recently connected a VDO sensor to the oil pressure telltale:

[TDNova]

i know andy already knows but to anyone else that doesent, i never removed the polo (i was told 15 qui for the inlet gasket so said no, tho i would have done it by now if it was still on the road) and i got a 16.400 sec quarter mile, i want another one and go further!

[andynova1389]

i havent removed the 'polo' yet but have turned the screw 1/2 turn. I cant seem to get over 12psi, even with the actuator pipe totaly off. I also took the air filter out and it did give me an exta 1-2psi. I blocked up the boost safy valve but it didnt make any difference. Only thing i can think of is ive got a weak wastegate, i might try taking the polo off anyway just to see what happens!!!!! It seem strange TDNova got over 1 bar without taking the polo out and i cant. Anyone else experienced this problem??

[DutchNovaDiesel]

Is that when driving ?

Mine went off the scale:

[andynova1389]

yeh when i floor it in 2nd or 3rd upto about 4000rpm. it wont go over 12/13psi. I blocked the boost safty valve off with gaffa tape and then wraped an elesctic band tightly around it. this should hold plus when i checked it after a run it was still stuck tightly.

[TDNova]

maybee it is a boost leak somewere else, maybee if your creative enough you cald try and jam the wastegate shut some how, have a look see what you can do but keep ur eye on the guage, obviusly lol. i know my dump valve would only hold 10psi then leak off, so i took it off, you dont have one do you?.
i am quite stumped other than that, lol
mine went right off the scale too but my guage was only a 10psi one, i honestly dont know what boost it ras running but i guarantee it was a lot more than 1 bar.

Dan

[andynova1389]

i assume i have my boost gauge take off in the right place. its tee'd of from the pipe which runs from the top of the cover u take off to get to the white ring!!!!!

[andynova1389]

does anyone know if the wastegate or actuator can be adjusted????

[mystery machine]

i did somit similar to my wife's 1.5td.... i wished i'd done it years ago. still returned 50+mpg taking it easy, and ran out of gears when driving it hard. easy mod to do, so much fun forever more.

[andynova1389]

so much fun forever more.

well not for me at the moment any ideas?

[TDNova]

i would love to help you out with this but i am right out of ideas apart from air leak, do the polo mod and check the manifold gasket it might just be this thats at fault. hope you sort it mate cos it really is great fun hehe.

[Paul]

What kind of BHP increase would you guess from these?

[DutchNovaDiesel]

Depends on how far you take it, Kris TD's corsa had 99Bhp and 132Lb/ft (coming from 67Bhp and 97Lb-ft) and that's without intercooler.

[TDNova]

i dont knwo what the most anyone has had out of the 1.7s but i saw one with a quoted output of 130 bhp, cant remeber the torque figure. and that was in a nova with no intercooler.

[Paul]

How did you go about making your inlet manifold pal?

Paul

[DutchNovaDiesel]

I took a couple of angle grinders and went mental on it !


J

[Mullen2006]

hi i have a 1.7tds astra was wondering if putting an induction kit on would be ok and a back box jst thinking of the sound it will make as diesels sound like a truck also if there are any other ways to increase bhp on it please could you tell me

[Paul]

I think there is enough ideas if you read the above mate!

[Mullen2006]

all sounds a bit complicated to me dont wonna blow the thing up or do summit wrong to it anyone in the north east who cud do it for me increase the boost and let more fuel through