hi, i am trying to time my 1.7 dtl gm engine astra diesel and cant do it . i have tried to time it without a dti gauge is it possible ?? i had it running but it takes a real long time to start and alot of the time i am having to use jump leads because the battery goes flat through turning it over to much I really need information as to whether I use a DTI gauge.
any info would be really greatfull
cheers
shouting removed
Edited by Pugugly on 03/10/2008 at 00:59
|
Every GM diesel engine from 16D onwards(early 1980s) with conventional injector pumps needs the pump to be timed with a DTI.
For cam timing, 16DA onwards (mid/late 1980s) should be timed using a DTI on the cam rather than via the locking plate fitted to the vac pump/distributor flange.
So, the short answer is yes, you need to use a DTI to time it properly.
|
hi, thanks for reply, today its been set up with dti gauge correctly but still taking a time to start, any other ideas as to why this could be "PLEASE"
thanks
|
Let's go back a step. Why are you trying to time the engine? When did the problem starting begin? Give us the full story.
|
right, i bought the car with faulty diesel pump, this was aparently diagnosed by vauxhall, i took the rocker cover off to check tdc when fitting a new pump and new belt and noticed 2 followers had snapped hence the rough running "that was the problem not the pump" anyways thats the update.
any info please matey
cheers
|
>>matey
Careful now!
OK, the snapped rockers mean that the valves have hit the pistons. Do you know why this happened?, i.e., have you found the root cause?
When you say that you have timed the engine, have you timed both the fuel pump AND the cam? To time the cam is more than lining up some marks on the pulley, because there's no key between the pulley and camshaft - you need to use a DTI in a fixture to set the cam position with the pulley loose on its taper.
When you've got the cam timing and the pump timing right, doing a comression test would be the next step - sometimes, you can get away with just putting new rockers in, as the genuine GM rockers are designed to fail like this if there's any contact. Spurious aftermarket rockers don't have this nice feature.
|
easy,
genuine vauxhall ones snapped, i dont think the valves could of touched it sounds to nice when it does run
cheers mate
|
|
they break cos the valves have kissed the pistons (they are designed like that) sounds like the pump timming is out to me, the mark on the pump pulley is a base setting, you need to set the pump with a dti (where the injector pipes come out of the pump there is a plug with a copper washer remove and fit the gauge there)
|
|
|
>>easy,
If it's so easy, how come your engine isn't running?
:-)
>>genuine vauxhall ones snapped
They don't snap unless the valves hit the pistons - as Topbloke says. Sometimes, you can get away with it, and you don't have to take the head off - hence my suggestion of a compression test, once you're sure the engine is properly timed.
Have you checked all the other rockers - sometimes, you'll find them cracked underneath at the weak spot, but not fully broken after there has been an "incident".
How did you fit the new rockers?
Valves which have hit, and are slightly deformed may reduce your compressions enough to make the engie difficult to start, but, once running, it will seal sufficiently to allow the engine to sound sweet enough.
You haven't said what it was that you were timing with a DTI - it should be both. Unless you do this properly, I don't rate your chances of ending up with an engine that will run well.
|
i used the vauxhall tool to comprese the rockers then slid the cam out.
i have only used dti to time the cam, i havnt timed the pump thats something i didnt no !! is it a hard job ??
|
|
|
|
|
