What should vacuum be??

[Inferno]

No cam, stock motor... trucks running funny.. orderd the moats stuff yesterday.. thinking before I start tuning I want to make sure I have no intake leaks.... can the vacuum reading tell me this ?? I have 20lbs at idle...

 

[bezerk]

Re: What should vacuum be??

No cam, stock motor... trucks running funny.. orderd the moats stuff yesterday.. thinking before I start tuning I want to make sure I have no intake leaks.... can the vacuum reading tell me this ?? I have 20lbs at idle...

that should be it on a stocker. 20-22. disrcibe funny

 

[Inferno]

Re: What should vacuum be??

on any type of load the truck bogs and misfires and sputters and sucks... I have been dealing with this for almost two years... and am now dead set on fixing it... I am gonna scan tomorrow night and post a bin and hopefully get some help on this..

 

[bezerk]

Re: What should vacuum be??

do a tune up first, check timing, plugs wires cap. than hook up scan tool. no check engine lights?

 

[Inferno]

Re: What should vacuum be??

bro... I have done a tune up every two months or so, hopeing I either missed something or got something defective.. PLugs, Cap, Rotor, Coil, Dist, Ign Module, Map sens, ECU, Prom, vac lines, even ran a bunch of cleaner through it and did noid checks on the injectors... I am so stumped...

 

[TYRODD]

Re: What should vacuum be??

Engine vacuum is different at varying altitudes/atmospheric pressure. My truck at 5300ft reads 15-16inHG at idle, but in KC it reads 20inHG, MUCH lower elevation, though I'm not sure what the elevation is there.

 

[bezerk]

Re: What should vacuum be??

bro... I have done a tune up every two months or so, hopeing I either missed something or got something defective.. PLugs, Cap, Rotor, Coil, Dist, Ign Module, Map sens, ECU, Prom, vac lines, even ran a bunch of cleaner through it and did noid checks on the injectors... I am so stumped...

checked timing? you can do a test to see if you have a leak somewhere, take of the tube that's between your turbo and intercooler and fab up a piece of rubber and put some presuure on it, you can check for leaks that way.

 

[Inferno]

Re: What should vacuum be??

Alt here is just over sea level... I have not checked timing.. I will do that tomorrow night.., and if I remember correct, just remove est wire, start, and make sure it reads 0 on the marker ??

 

[bezerk]

Re: What should vacuum be??

yes, but the marker might have slipped though. you might want to take the sparkplug out and check it with your finger or something like that, just to be sure

 

[SY2455]

Re: What should vacuum be??

After you check your timing, you may want to check for a bad Cat. If it is plugged or melted then you can't get the exhaust out and that will give you the same results as you talk about in post #3.

 

[Don W.]

Re: What should vacuum be??

Another thought would be to check fuel pressure, if you haven't done that already. What you say tells me it's ignition. Have you tried a different module? Coil? :2cents:

 

[Inferno]

Re: What should vacuum be??

funny you say fuel pressure, I am getting 40 at idle and 60 when accel... but my gauge ticks and oscilates... makes almost like an injector noise and goes with rpm...

 

[BoostedSUV]

Re: What should vacuum be??

What spark plug gap are you running? I had a similar issue and tightened up the gap and it made a word of difference. Turbo was blowing out the spark. Also u didn't put a 3 bar map in place of 2 bar did u? That will do what u are describing if chip isnt setup for a 3 bar...

 

[Inferno]

Re: What should vacuum be??

what about vice-versa, I thought I was supposed to have a 3 bar and just checka nd there is a two bar in there.....

 

[BoostedSUV]

Re: What should vacuum be??

It would do the same thing vise-virsa but our trucks come stock with a 2 bar map. If the chip was change to have a 3 bar it won't run right with a 2 bar.

 

[Inferno]

Re: What should vacuum be??

do you have a recomended gap ??

 

[Aeroking]

Re: What should vacuum be??

do you have a recomended gap ??

what do you plan to run, how much boost? any meth?


you mentioned your fuel pressure bounces. do you have the stock pump? your pressure should increase with your boost 1-to-1.

 

[BoostedSUV]

Re: What should vacuum be??

I run mine at .025 but I have an aftermarket turbo etc. I wouldn't gap them much more than .030 to .032 with a stock turbo