Delivery Valve Question

lastcall190

lastcall190

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Feb 3, 2010
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Good afternoon. I have a 97 12V and when I got the truck it had full cut DVs in it, no gauges, and no other pump tuning (besides a fuel plate). AFC standard position, plate in middle, no starwheel, and no pre-boost adjustments. I dumped the full cuts and grabbed some 181s. Before putting the 181s in, the truck would fire right up with a touch of the throttle. It was flawless. After putting the 181s in, it has ceased to start properly once. Even before it got too cold (this was back over Thanksgiving weekend), it would fire off, but sputter and die right away. If I gave a little throttle to keep it alive it would stay running just fine. I checked for leaks at the connections of the high pressure lines to the injectors, and they look good. No fuel leaking. Am I losing my mind, or would changing DVs change the startup behavior of the truck? Or does it sound like my problem lies elsewhere... if I should wait to come up with a verdict until after my gauge is hooked up, then so be it. If this is a bonehead question, well, I'm learning :bang Thanks for your input.

-J
 
Haven't tried raising the idle yet. When I did the crank seal and put back on the RPM pickup thingy (whatever the F it's called), I used a feeler gauge to get the distance to the crank pulley right. When it's "cold" the idle sits at 750RPM. As it warms up it gets to what I might guess would be 775-850RPM.

Another example, I took it last week to my parent's house to work on it a bit. A few hours later I fired it up, and it started without having to dance on the throttle, but it didn't snap up to idle well. It kinda started lazy and hung below 750 for a second then climbed back up. I explained that awfully but I'm not sure how else to say it. Bottom line, is that if it sits a few hours, starts up "ok". Any more than that (read: overnight), and it's a I stated above. Think I should futz with the idle screw at all? Could my tach be WAY out to lunch? Thanks for your input.

-J
 
have you tried putting the full cuts back in and see if it fires right back up? to make sure that everything else is fine? i would try that and then inspect the shut off lever and throttle linkage and make sure they are not hanging up any.
 
The tach could be out, but I can't see it out that much. Does it sound like its much slower than 750 rpm? The tach in my 24v is bang on.

Try raising the idle up to 900 when its hot. It'll probably be a bit more than 750 when cold. How does it fire if you give it a quick blip of the throttle? My 12v likes a little throttle to start up fast. If I give it a little pedal, it will fire in about half a revolution. If I don't, it will take 2 or 3.
 
The full cuts will drop idle down some, with 181s it should have gone up a tad, something else sounds at fault here.
 
Chevycummins said:
have you tried putting the full cuts back in and see if it fires right back up? to make sure that everything else is fine? i would try that and then inspect the shut off lever and throttle linkage and make sure they are not hanging up any.
Click to expand...

Well I didn't, as I sold the full cuts. Maybe a poor decision but I didn't see much use for them in the future. I will check out the shut off lever to make sure it's pulling up all the way when I do my shocks later.

Tate said:
The tach could be out, but I can't see it out that much. Does it sound like its much slower than 750 rpm? The tach in my 24v is bang on.

Try raising the idle up to 900 when its hot. It'll probably be a bit more than 750 when cold. How does it fire if you give it a quick blip of the throttle? My 12v likes a little throttle to start up fast. If I give it a little pedal, it will fire in about half a revolution. If I don't, it will take 2 or 3.
Click to expand...

See I can't remember what it sounded like when I first got the truck, but it sounded a lot healthier... When I first got the truck it liked a quick blip of throttle. Now it does as well, but instead of firing off good after that the motor is kind of saying, "oh... it's time to start? ok lemme get out of my chair..."

I will try raising the idle a bit and see how that works.

Timebomb said:
The full cuts will drop idle down some, with 181s it should have gone up a tad, something else sounds at fault here.
Click to expand...

Thanks, yea I am going to check to see what my FP is like, see if I'm letting air in somewhere. The insight by all is appreciated.

-J
 
I had a simular problem yesterday. i took out my 024's and re installed the stock 181's. it started and ran really smooth at idle, but when i drove it, it was like driving an a 20* morning with a cold engine. it sputtered and smoked had no power. i dont think i could have hit 50mph. and the engine was compleatly warm and it was 60 degreese out. what could have caused this?
 
I've been having some issues with the seats not sealing on the 181's lately, a heat gun on each cylinder during warm up is interesting.
 
Smokem said:
I've been having some issues with the seats not sealing on the 181's lately, a heat gun on each cylinder during warm up is interesting.
Click to expand...

You thinking lack of fuel lubricity causing wear or something along those lines?
 
The seat design not sealing against the barrel. All aftermarket delivery valves use the 131 seat.
 
Smokem said:
The seat design not sealing against the barrel. All aftermarket delivery valves use the 131 seat.
Click to expand...

I see. In your opinion is it worth it to seek the 131 seat? I was lead to believe the 181 seat was the hot ticket but I see why it may not seal as well given the lack of surface area at the base compared to the 131 seat.
 
The delivery valves I am sourcing have the 131 style seat, and that is what I would like.
 
Smokem said:
The delivery valves I am sourcing have the 131 style seat, and that is what I would like.
Click to expand...

Weston, i really need some delivery valve help. you told me that you had something that you were working on about 6-8 months ago, that you thought could be bennificail to my setup. i know you have alot of projects you are worknig on, but did you ever come up with the DV's you were working on?
thanks for any input.
 
Was working on it, lost interest, now I think I will have a few sets in a month's time. Why not put the 024's back in?
 
Smokem said:
Was working on it, lost interest, now I think I will have a few sets in a month's time. Why not put the 024's back in?
Click to expand...

i did about 30 min later. i wanted to try the 181's because i will be towing my toyhauler (11,500lbs) and was seeing if the 181's would run cooler.
 
For what it's worth just thought I'd bump this in case anyone else had similar issues. I raised my idle a touch and it helped greatly. Truck starts up very good now and with no drama. Don't even have to aid with a blip of throttle anymore. Did I hide a deeper issue or is this a reasonable fix? Thanks.

-J
 
lastcall190 said:
For what it's worth just thought I'd bump this in case anyone else had similar issues. I raised my idle a touch and it helped greatly. Truck starts up very good now and with no drama. Don't even have to aid with a blip of throttle anymore. Did I hide a deeper issue or is this a reasonable fix? Thanks.

-J
Click to expand...

I agree the issue lies with at least one of the dv seats not seated against the barrell. Fire the engine while cold and by placing your hand on each of the exh. outlets on the head within a couple minutes you will find the obvious cylinder thats down... or not firing. You can swap the dv from that cylinder to another to confirm the issue, the dead cylinder will move to the other hole. The 131 seat is a much better design in my opinion lap your 181's into a set of 131 seats.
P.S. You can also crack the Inj. lines at the pump and you wont notice a change in rpm like you will with the cylinders that are hitting correctly. Ryan
 
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stock600 said:
I agree the issue lies with at least one of the dv seats not seated against the barrell. Fire the engine while cold and by placing your hand on each of the exh. outlets on the head within a couple minutes you will find the obvious cylinder thats down... or not firing. You can swap the dv from that cylinder to another to confirm the issue, the dead cylinder will move to the other hole. The 131 seat is a much better design in my opinion lap your 181's into a set of 131 seats.
P.S. You can also crack the Inj. lines at the pump and you wont notice a change in rpm like you will with the cylinders that are hitting correctly. Ryan
Click to expand...

Thanks i might try that too.
 
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