Author Topic: Lopey Idle (Read 6359 times)

zukgod1 · « **on:** March 02, 2008, 10:44:23 am »

So anyone know why my car lopes?

I'm going to attempt a short vid so you can see what up.

It sounds like a big block V8 with a huge cam in it.

Timing is set to 1.mm, I was going to go with 1.05mm but my injectors are set @ 139bar instead of 155 bar.

The IP has a 10mm pump and a 1.9 AAZ cam plate. I installed some larger Delivery valves and I kinda think that's where the problem is but before I tear into it I want to ask some questions.

Stock cam

K24 with a full 3" system from the turbo to the rear bumper.

Seems to run great once you get it past idle, heck I can hit 30psi without trying very hard.

It's a hydro head on a mechanical block with the metal head gasket and ARP head studs.

Suggestions?

jimfoo · « **Reply #1 on:** March 02, 2008, 10:49:48 am »

Well one thing is with the lower opening pressures, it is going to advance your timing more than what you have it set at.

zukgod1 · « **Reply #2 on:** March 02, 2008, 10:52:39 am »

Quote from: "jimfoo"

Well one thing is with the lower opening pressures, it is going to advance your timing more than what you have it set at.

Yes that's why I didn't go the full 1.05mm.

That shouldn't create a lope though, ping yes lope no.

zukgod1 · « **Reply #3 on:** March 03, 2008, 07:46:09 am »

Any of you savy diesel tuners have suggestions as to why it's idling like this?

jimfoo · « **Reply #4 on:** March 03, 2008, 08:41:59 am »

Could a slightly bad spray pattern be worse at low fuel, causing poor atomization and poor burning. Maybe a small pit or scratch that doesn't have much affect at higher fuel? Just a thought...

zukgod1 · « **Reply #5 on:** March 03, 2008, 09:35:34 am »

Quote from: "jimfoo"

Could a slightly bad spray pattern be worse at low fuel, causing poor atomization and poor burning. Maybe a small pit or scratch that doesn't have much affect at higher fuel? Just a thought...

Maybe, the injectors are brand new, as is the pump and the engine.
Has maybe 40 miles on it.

When it's warmed up and idling (sounds the same) it blows black smoke with each pulse, kinda looks cool but I would rather have a smooth idle.

I wonder about the 1.9aaz camplate?

rabbitman · « **Reply #6 on:** March 03, 2008, 02:22:27 pm »

zukgod1 wrote,
the injectors are brand new

My wild guess would be that you have a malfunctioning injector, I think I recall hearing someone had a broken injector spring a while back. It sounds like your getting big droplets of fuel instead of a fine spray. Just my one cent.

zukgod1 · « **Reply #7 on:** March 03, 2008, 02:39:07 pm »

Quote from: "rabbitman"

zukgod1 wrote,
the injectors are brand new

My wild guess would be that you have a malfunctioning injector, I think I recall hearing someone had a broken injector spring a while back. It sounds like your getting big droplets of fuel instead of a fine spray. Just my one cent.

I suppose thats a possibility.

I could crack the lines one at a time to see if there is one cyl that different than the others I guess.

I wonder if they are just way to big.... ??

If I can stomach the cost I'll get another set of injectors done with stock tips and give them a try I guess.

dillenger1 · « **Reply #8 on:** March 03, 2008, 03:17:34 pm »

How big are these nozzles your using?

zukgod1 · « **Reply #9 on:** March 03, 2008, 03:28:50 pm »

Quote from: "dillenger1"

How big are these nozzles your using?

Lets just go with huge.

They are off a CASE back hoe.

I have a stock engine not counting the metal head gasket and ARP studs and with the K24 30psi is not a problem at all.

It will go much higher from what I can tell but being brand new I think I'll hold off a tad on the floging.

I'll see if I can get a part#

Tintin · « **Reply #10 on:** March 03, 2008, 08:00:48 pm »

''some larger Delivery valves'' what is this delivery valves you talk? the 4 screwed in the Head&rotor?

Try with the original one from your engine, I had some poor idle problem with improper delivery valve.

zukgod1 · « **Reply #11 on:** March 03, 2008, 09:42:19 pm »

Quote from: "Tintin"

''some larger Delivery valves'' what is this delivery valves you talk? the 4 screwed in the Head&rotor?

Try with the original one from your engine, I had some poor idle problem with improper delivery valve.

The delivery vale is the one that screws in the pump head like you mentioned.

I reinstalled the original ones, no difference at all.

I'm wondering still if the injectors are just to damn big.

zukgod1 · « **Reply #12 on:** March 25, 2008, 09:59:41 am »

I'm going to bump this up for more input.

I changed over to stock injectors and messed with every setting on the pump and got it idling smoothly. I re installed the other larger injectors and still had a good idle.

Well last night I decided to check my internal pump pressure, I have a banjo bolt (large return holes) with a fitting on the end that I can attach my FP gauge up to so I did.

As soon as I started it it raced, maybe about 2000 rpm (no tach).

My pump pressure was @ about 28psi, I taped the pressure regulator a bit and it went to 35 another tap and it didnt more anymore. At that point I looked at the regulator and i had driving the damn thing a good 3/8" down, so crap..I shut it down removed the regulator reset it and found another fitting that I could block off so there wasn't a return while setting the pressure.
I set the regulator to approx where it was originally and fired it up.
Chug chug chug died. Restart attempted to give it a little throttle to get it running and no throttle responce, now I'm getting frustrated.
I adjust the idle up and pull the lever then restart, it idles just very low and lopey. I checked the gauge and it was on zero (I thought) I hit the relief button and it wasn't on zero it was all the way around and back to zero so closer to 160 psi :shock:
shut it down in a hurry and removed the bolt and reinstalled the OE bolt and restarted, lopey low idle again. SH*T!!!!

So I play with the settings for about a hour and nada, unless the fast idle is out it idles to low and I cant adjust it up.
If I turn in the max fuel screw I can bring the idle up to where it's smooth but it wont idle down after you hit the go peddle, just hangs.

So I backed the idle bolt back out all the way and attempted to set the idle with the screw on the fast idle which is what you are suppose to be doing but I still cant get it to idle up enough to smooth it out.

If I back the max fuel screw out to where it will idle down after hitting the go peddle the throttle responce is crappy and still idles to low.

I'm lost, I've replaced the lines looking for an air leak, even installed a pusher pump back by the tank.
Nutin.. :cry:

I desperately need some guidance/ ideas here.

myke_w · « **Reply #13 on:** March 25, 2008, 11:31:15 am »

if this is still relevant... blows black smoke with each pulse

this is a crazy suggestion, but what the hell..

so if you had a "miss" on a gas car, you might pull an injector plug to find the miss (what hole it was on)

so why not get some rags and safety glasses and gloves and crack each injector like at idle and see which one changes most or least?

this way you can narrow down what hole it's coming from and work from there..

zukgod1 · « **Reply #14 on:** March 25, 2008, 11:49:46 am »

Quote from: "myke_w"

if this is still relevant... blows black smoke with each pulse

this is a crazy suggestion, but what the hell..

so if you had a "miss" on a gas car, you might pull an injector plug to find the miss (what hole it was on)

so why not get some rags and safety glasses and gloves and crack each injector like at idle and see which one changes most or least?

this way you can narrow down what hole it's coming from and work from there..

i did that, sorry I forgot during the typing frenzy above.

I cracked each injector to see if it was one hole creating the problem but no.
All were the same reaction to the loose lines.

The idle is just to low and I cant get it higher without it running away ..??