2.4 timing and idle speed on a '97

Hey all, I finally got a new cylinder head for my 1997 Taco. The engine is put back together but my idle speed seems higher and the engine stumbles when I accelerate. Right now the idle when the engine is warm is around 1100 - 1200 RPM's. I remember the idle being around 850 - 900 RPMS before with the old head. I cant find any vacuum leaks that would be causing this. Could it be possible that I need to retard the timing by a tooth? Does the OBDC tell tell if timing is off? I put a OBDC reader on the plug under the dash and it says everything is ok with no errors being reported by the engine's computer. Let me know if I might be missing something else..

-Karl

 

clean the throttle body and iacv

 

I'll look them up and search for threads on that. Just so I understand the big picture, is timing advance and retard set by the computer? I dont see how the dizzy is adjustable so as far as I know I just make sure the rotor is at #1 terminal at the cap when the crank and cams are at TDC, correct?
-Karl

 

Here are some pictures from my scanner for what they're worth.

 

and timing advance at different RPM's.

 

Ground zero would be MAF check.....and/vacuum leaks.....
thats about 75% probs here......pcv valve leak ect....

Next easiest to check......check all around you injector cups...
make sure those cups are right....

Its all a process of elimination...

days of retarding ignition are over.....that went out with carb's.....
unless you want to spend $1500 on a custom fuel management system...


NExt I'd venture to the butterfly in the throttle body...
.....it must close fully at idle.....unless boosted by vac from steering, tranny, or a/c controlled switches.....all possible trouble spots....


Its not common to get a leak at the intake gasket....but never know....

 

Would spraying starting fluid at the potential vacuum leaks be a good way to find them? The new injector cups arent completely flush with their holes in the new cylinder head. I guess I could tap them in more, I'm just afraid of breaking them.

 

have a fire extinguisher ready