Offroad-Express

just installed a manual boost gauge in my 93 vx cruiser. question is should i be getting a vaccum reading at idle as the only reading im getting is boost, the needle just sits at zero when idling.

cheers jono.

Mine sits at nothing, diesels don't create vacuum like a petrol does.

Most toyotas have a vacuum pump run off the back of the alternator.

Correct me if I'm wrong, one of the things I've always been unsure of...

sound right,iv only ever had -ve boost when coasting down hill under engine braking

dirty diesel motors dont have a butterfly this is wot causes the vacuum in the petrol motor.

Yes you should a little vac when using the engine as a brake down hill

jono

cheers for that, thawt that was the case. out of curiosity what boost readings are you getting

mmmm factory i dont know as my truck not factroy when i got it

currenlty running 15 psi with a fuel pump adjusted. have just got it back from a tune up again. have have it spike up to 18 - 19 psi when out in the mud.

what reading are you getting

10 psi factory.

It's seen 18, but I think the majority of it was escaping out the headgasket somewhere

mines reading 12. what will they safely run at if i want to increase as the local turbo guy at turbo tech wanted to increase it. do you just increase fuel to get more boost.

jono

yes and no

need to increase air pressure then allow the right amount of fuel.

ned to watch temps very closely. or the motor will stop with a bang,

its taking some time for me to get this far. and a very freindly man ith all the know how. i would hate to have to pay for it all

all im after is a little more to run the 35's nicly. i wont to run down the basteds that tail gate me hehehehe.

im happy at the mo the truck gets up and buggies now very nicely. if only i have a set of standard tyres i think i would be worried.

wife has the truck during the day and she keep gettin it crossed up in the rain.

firestonecruiser wrote:just installed a manual boost gauge in my 93 vx cruiser. question is should i be getting a vaccum reading at idle as the only reading im getting is boost, the needle just sits at zero when idling.

cheers jono.

some motors will read vacuum at times. thats generally due to the EGR butterfly closing and the EGR valve staying shut (or blocked)

sound right,iv only ever had -ve boost when coasting down hill under engine braking

Yes you should a little vac when using the engine as a brake down hill

i can get a couple of lb's of boost going down hill even under fuel cut in the navara. thats due to the EGR system being disabled.