No Vacuum

[ecbach82]

So I just swapped my stock ka24e from my 89 240 and i put a ka24de (92 240sx) in it. And now i have no vacuum at all. At any point. help appreciated. i looked through other forums and saw nothing like this

i have no knock sensor at the moment.

[dc1984]

ushould try explaining things a little better, u know, kind of paint a picture for us as we are not mind readers. i mean, is the engine starting, starting then dying? there aint much to go off here.

not trying to be a d!ck though so dont get the wrong idea

[ecbach82]

no offense taken. the engine started at first but i'm beginning to think it was just leftover fuel. now it wont start. it sounds like it wants to. the engine just isn't getting fuel. a buddy of mine told me check pumps and injectors. i checked and re-checked. so when i checked the vacuum i realized i had none. its not a leak because i have no vacuum from point a. little more helpful?

[dc1984]

so ur trying to check for vacum while the engine isnt running? cause i think it needs to be running in order for ther to be any vacum. try checking ur MAF and spark, timing too.

[ecbach82]

Does there need to be vacuum to allow fuel to get into the fuel rail? I don't think it is getting fuel and it seems that the regulator would need to open......

[nismoracingsx]

so you've confirmed that your fuel pump is in good working order? After you turn the key forward and the pump primes, turn it off and check a line near the fuel rail to see if there is fuel...if you have no vacuum and you think its the regulator..just unplug the vacuum source from the regulator and it should open all the way.

No vacuum is bad though...no vacuum means something isn't sealing if you have no leaks..i would check compression and timing there killer

Good luck.

Just remember your basic elements needed for an engine to start and run and it will help you diag. your vehicle. ie. fuel, air, timing, compression, etc. once you narrow it to a particular area, then start testing compenants instead of testing blindly. GL

[1KleenS13]

No vacuum...................huh, are there rings on the pistons?

The car needs a vacuum to run, start. That happens when the intake valve opens and the piston moves down. The regulator does not need vacuum to start the car ( it would run with no vac line on it). If you dont have fuel the car wont start. Check your pump and the wiring for the fuel pump.

[ecbach82]

the wiring and everything is good. nothing else was wrong with the car when i did the engine swap. i appreciate the help though guys. thanks.

[desertdustr]

Won't start,........That short sentence covers alot of area. I'm assuming you don't hold a PHD in automotive engineering. (that's ok, nobody does, I don't believe the title exists.) So, you do what the rest of novices, and often times, even pro's, do, (w/ technology cruisin in the "rocket lane", ...nothing stays the same.)go to the basics. The internal combustion engine still requires three basic elements in order to run, air/fuel/ignition(spark) Considering you just swapped engines and assuming the engine just installed was a runner before installation, then you've, concievably, over looked some minor electrical connection depriving the engine of one of the three.(ie power to the fuel pump circuit,(fuel) ignition switch circuit,(spark) or somebody stuck a sock in your afm.(air) (I wouldn't concern myself to much with that last senario.) I would suggest, however, to download a factory service manual, NOT, the Haynes or the other published rubbish portraying themselves as "Service Manuals",(worthless !) that adresses your new engine's needs. A last thought, is the "89" ecu compatible with the "92" ?? I think you'll like your new engine. Good luck.

[ecbach82]

i swapped out ecu's. wasn't taking the risk. i think im good though now. thanks for help guys

[kpariaug]

i had a simular problem once, i hand tightened one of the cam timing gears and is slipped off the key and rotated a little out of line, the motor turned over just fine but built no compression so no vac either. and it just sounded like a motor turning over under no stress because there was always a valve open for air to escape.

i dunno if you messed with timing but it might be something to look at.

ok, i didnt see the above post
Modified by kpariaug at 4:58 PM 4/2/2009

[tercel drifter]

Some one correct me if i'm wrong but i don't think running without a knock sensor will do any harm. The enging advances it self to the max and retards when knock sensor detects. ACtually ya i guess you could screw ur motor without it now that i think of it lol.