90 240sx Boggs down on acceleration

[chance2b]

Hello to all, My son has a1989 240sx that we are working on, production 1/89, manual trans, and a KA24E engine. The car will start fine, revs up to 2000 rpms for a minute then drops to 1000 rpms and stays there at idle with engine hot or cold. I can detect a small miss at idle, more so when cold. With the car in neutual it will take throttle fairly well with some lag noted. (no skipping) But under driving conditions as long as you ease on the throtle the engine runs fine through all 5 gears all the way to 5000 rpms. but anytime you push the accelerator it boggs down bad! it does not skip or backfire, and will gradually build up rpms slowly. This corrects itself if you let up off the accelerator but it takes a second or two to straighten out. Like timing is lagging. What we did: Had head rebuilt, replaced timing chain assembly (NOTE) Please on these engines make sure you purge all the air out of the block,intake and heater coil. We took the head off and replaced the gasket thinking the first one hadn,t sealed properly. It was just Trapped Air.

Whats been done so Far1.moved time up and down (no difference with problem just labor knock )2. checked all vacuum lines3. checked all plug in connections for loose or corroded prongs4. replaced plugs and wires, checked cap and rotor5. Checked around intake mannifold for leaks6. cyl. compression tested Please any help is reallly appreciated Thanks
Modified by chance2b at 10:43 AM 1/16/2005

[Axel Grungy]

maf?

[chance2b]

It's Fixed. The beast is back.

Thanks for your reply AXEL.

WHAT FIXED PROBLEM

1. Missing while at idle ( EGR Solinoid Vacuum line split )2. Bogging on acceleration ( Mechanical Timing off about 40 degrees!!! Head Cam)Yes it will run, we reset timing

Don't know how we got mech timing off so far the first time. ignition timing was right on, would start at the touch of the key.

( Note ): Timing light in this case is useless.

With timming chain off

1. Set crank pulley to 0 degree mark. Orange, or red dot.2. Set cam pin straight up with motor not ground, Should be exact middle of rocker arm shafts.3. put chain back on ( mechanical time is set )