• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

bad porting suspect for uneven running?

How should I check the cam timing? I don't have any information about the cam.
I bought the cam from a local dealer that knows what he is doing, so I trusted him when het selected this cam for me. The cam is a kg17 from kgtrimnnig in sweden
 
Today I adjusted the valvelash to a 0,50mm feeler guage (0.20 inch) a 0,55mm (0.22) feeler gauge wouldn't fit trough.
I adjusted the exhaust of a cylinder when the inlet from that same cylinder went from open to closed I set the exhaust lash at the fully closed inlet position. When the exhaust cracked open I set the inlet. I believe this is a fail proof procedure. any comments on this would be nice :p

During my test drive I noticed my AFR/lambda reading's where lean! (17:1 lean) So something in the combustion is definitely changed! Because of the lean condition I couldn't feel if the stumble is still there. My guess is that more fuel is burning causing the lean condition. maybe no more mr misfire?

I'll go retune the MS to find out!
 
Monkey balls!

I retuned the engine.....



Not the result I wanted! The VE table went up for sure, but the stumble is still there!
I have a week full of driving to work to do, I will try some different tune's (ignition wise)

My last log

My last tune
 
Hopefully the power went up a little as well? Certainly a sign things are behaving somewhat normally.

Had much of a chance to look for oddities in the logs yet, for tach signal, accel enrichment, anything of that nature?
 
a bit smoother drive should be more power? I searched the log for accel enrichments, spike's or resets there are none.. I hit the space (manual mark) after I felt the engine run 'uneven' spark advance went from 26.6 to 25 on one event.

The tach signal is a tiny bit jumping up down, 20rpm the line is zigzag all the time.
 
Hmm, 20rpm is nothing, and the timing change is probably bouncing from one bin to the other. Pulsewidth staying pretty smooth when it happens? Mine when it does it's random unexplained burp, the PW drops to 0 for a split second, then back to normal.

I kinda wonder if maybe it's a funky characteristic of the cam perhaps?

Also, what's your vacuum like now, after the valve adjustment?
 
OttoB said:
I would check cam timing. I've met cams that heve been off 20 degrees.
Click to expand...

true that I had an autotech cam that was off by about 30 they put the key in the wrong spot.
best to use a degree wheel and a dial indicator on the valve stem and compare the readings to the camshaft manufactures specifications for valve opening and closing degrees
 
B-lennium said:
How should I check the cam timing? I don't have any information about the cam.
I bought the cam from a local dealer that knows what he is doing, so I trusted him when het selected this cam for me. The cam is a kg17 from kgtrimnnig in sweden
Click to expand...

KG17 has 284 degrees and 7,6 mm lift at cam. LSA 108, and I have similar Volvo cam 762 from Timos motors. If your cam is anyhow close to mine, you should have @ TDC intake open about 2 mm and exhaust 2,5 mm. These are measured direct from cam, zero lash.

My cam has max intake lift at 108 ATDC.
 
Tuning make's no difference, changing sparkplugs (used set) from bp6es to bp7es made it worse (a tiny bit). I am now fabricating a piston stop (kill an old sparkplug and put an bolt trough it) and degree wheel.

I'll try to find a decent priced IR thermo gun (250 degrees celcius is enough?) To measure the runner heat.
 
I know it's a new cam and lifters, but it almost sounds like a flat cam lobe.

I've had that happen multiple times on my abused B20's. The symptoms are always weird, I always suspect something else, until I pull the valve cover and rotate the engine around and the flat cam lob's failure to open the valve sticks out like a sore thumb.
 
It does sound that was doesn't it John. Had a couple over the years as well, just did one on a friend's B20 this winter, 1 was gone, 2 others were going. Being new I'd like to hope that's not the case though.

Plugs making a difference is odd, certainly leans more towards ignition side, unless the gap was different between the two.

Not sure if a 250*C gun will work or not, might need 400-500. At idle it's borderline, higher rpm than that it'll likely not be enough.
 
My new IR gun tells me all the cylinders idle at around 300* C but number 1 @270*C ! What could be the issue here? I see nothing differnet on the sparkplug's 1 and 2 (270* and 303*) And I am using my sparkreading black magic!
 
Hmm, tells me that's likely a problem hole, so certainly a starting point! Swap injector 1 and 2, then plug wire 1 and 2, then plug 1 and 2, see if any of those make a difference.

Also, is this on the coil packs still, or the dizzy? If it's the dizzy, that rules out most of the system from the dizzy on back to the coil, so just fuel, plug wire, or plug.

If swapping none of that makes a difference, and the valve lash and compression numbers are all the same as neighboring cylinders, plus cam lobe lift is the same, I'm getting to the point of being stumped.
 
If it was ignition two cylinders would miss not just one. And ignition coils either work or they dont.
Click to expand...
I replied False.
I guess you got butthurt on my reply and wrote this ?
Do you even read what the OP is saying? From this ignorant post i say no.
Click to expand...

Funny . I was looking for a gauge read not a map sensor read. Thanks.

Never heard anything back on plug wire resistance. Did op check this?
 
I think changing to the original distributor (inc plugwire's and new plugs) ruled out the whole ignition.

I did hookup a vacuum gauge, same as the mapsensor -0.20 bar the needle bounces a bit
 
You must log in or register to reply here.
Back
Top