Injection Pump Timing on 93 12valve?

[1stgen]

Does anyone know where i can find technical help on timing this pump? Any help appreciated.

 

[BushWakr - RIP]

Hey 1stgen..... what sort of/or what degree of technical help are you looking for... . ???



There are a number of "levels" for help on this topic.

d

Lets start with some of the basics first, if that's ok. .



There are three methods of timing these pumps:



1) you can use the "mm, or plunger lift" method. That requires a dial indicator, magnetic base, some crows foot wrenchs and some time... a fair bit actually. This is the most accurate method of doing the timing on a VE pump... in fact it's also used on other pump types as well.

If you look on your gear case, drivers side, midway right next to the injection pump you'll see the truck/engine data plate.

This will have a number of different things on it but the one you're looking for is pump timing... . it will say you pump's timing is/should be 1. 25mm lift.

If your truck is stock and the pump is original and untouched then you are fairly secure in thinking that your pump timing is pretty close to that spec.

(**NOTE** earlier trucks ran between 1. 35 and 1. 40mm lift... . also note, that this is were some of the head scratching can come in... )



When you use that method you'd be "right in the zone" for timing your pump by setting to 1. 5mm to 1. 6mm

Now, that is a bit of advance but still fairly safe... (here's the confusing part... ) there are no set "tables" for converting your mm plunger lift to traditional "degrees advance/retarded" style measurement, at least none I have ever seen.

So... . you gotta use some of the tried and fairly true methods when it comes to this (second) method. . (degrees)



What you are trying to accomplish is setting your timing with some advance to address four things... smoke, compensating for injection timing delay (retarded timing) caused by higher release pressure on upgrade injectors, responsiveness and, overall power. To a degree more advance will improve these things... to a degree. .

When you use the second method, (degrees), you'll find that rotating the pump body upward towards the head will advance your timing. It is fairly common to use 1/8" seperation between the two index marks, one of the pump flange, one on the gear case. Coincidentally when you use this method it will equate to roughly 1. 50 to 1. 6mm lift... .

So..... 1. 25mm equate to approx 12. 5-13* advance and to raise it you need to rotate the pump upward by 1/8" and this will result in a total advance of approx 15. 5-16*.

Wild huh... .



Oh ya... . the third method... find someone who has done a few of these and has a good ear... . that person should be able to get within a degree in determining your advance just by listening and doing a couple simple tests... .

Piers has won more dinners and drinks by getting within 1/2 of 1* than you can shake a stick at... . I hate it when he's that close... it just,. . aint fair ya know...



Is that ANY help at all. . ???



pb... .