1997 Hardbody

[CoilOVerKid]

Hey guys, I'm having a hard time diagnosing my dads truck. It's got a single slammer KA24e. The condition is strange, at times it starts really easy but you cannot rev at WOT. Meaning, if you crack the throttle plate into a WOT condition the revs actually come down until it shuts off. Just boggs, but if you ease into the throttle you can accelerate from idle through red line. Also at times, while turning the truck over, It sounds like the engine misses the compression stroke and you can visually witness the whole rotating assembly spin backwards then you can hear the valvetrain making ticking noise and the truck has a hard time starting. Also while this occurs and with the air cleaner off the throttle body, you can see blue smoke come out the intake which is oil. Please help we need to get this running ASAP.

 

I've not done a compression test yet.

 

update performed compression test

cyl#1 180psi

cyl#2 180psi

cyl#3 160psi

cyl#4 165psi

[flatcat19]

This thread sux without pics, why the fuck would you start a thread about an object and not post pictures what a moron :wacko:

[datzenmike]

Hahahahaha ...... good.

 

Sounds like it might be backfiring out the intake. Check ignition wires and under cap, maybe spark jumping onto, and firing another cylinder than the one it's supposed to. A burned intake valve can do this too.

[HRH]

Have you checked your timing? Have you checked the 02 sensor? 96-97 D21 KAEs were their own year range, heads are different and obviously OBD II, not I. Sensors are more at issue, but major issues like that sound like something misadjusted. Perhaps a severely slack chain, but even that it should rattle and run. That distributor has an internal coil, which could account for something.

 

On the compression readings, the back two having 160ish and the front two 180 is not a good sign. You might take off the valve cover and look for problems. Lots of things come to mind. As always:

 

Start with the basics.

 

Timing

Check for intake leaks (vacuum leaks)

Look for obvious issues (sensors dead, missing, misadjusted)

[lil89ram50]

check fuel pressure?

[frodo70444]

two cylinders next to each other with lower compression? headgasket? either way stop reving it lol

[datzenmike]

update performed compression test

cyl#1 180psi

cyl#2 180psi

cyl#3 160psi

cyl#4 165psi

 

 

Just saw this. Possible small hole between #3 and #4 head gasket like frodo said. When #3 cylinder fires (under heavy throttle) #4 piston is approaching bottom dead center and the cylinder is full of gas and air and ready to start the compression stroke. Heavy full throttle will give maximum cylinder pressure and the flame could be pushed through a small head gasket hole setting off the #4 cylinder. Because the intake valves are still open for 50 or 60 degrees the flame travels out the port as a backfire.