12v Slow acceleration, Excessive, smoke Low idle, more whipple
 

uI have a 98 12v. Boost elbow (kept below 35psi), 4kgsk, #0plate, 4 clicks, gauges. Recently myu is having the issue of slow acceleration from the line, lots of smoke, and low idle both in and out of gear. I recently had the fuel filter and oil changed and a valve adjustment done. It ran great, but I drove about 100kmi and now it is doing this. It idles at about 7200rpm in gear and 65000 in Neutral. It also whipples alot easier than it used to when I let off of the pedal. I know this is too low and it started doing all of this at the same time. I have heard it could be boost leak, and I also though Torque converter, but TC wouldn't affect neutral idle. Also its not the air filter either. Please help as I am traveling on the road now, thanks!

when were the govoner springs installed. this can cause problems. what is your fuel pressure what condition is your turbo in. charge air cooler leaks? are you still making 35lbs of boost?

I installed the GVSK about 3 months ago. Took it to a diesel shop to double check my work, all they did was adjust the idle up. Fuel pressure gauge doesnt work right now so I do not know. I haven't tested for any leaks yet. I haven't got a chance to get on the highway and really punch it to see if it is still making 35psi. The turbo is stock with 268k miles on it. Also its only been 1k not 100k sense all this work was done. That is a typo.

gotta do some tests bud. and please get a working gauge on your fuel pressure before you kill the pump. heavy black smoke and slow acceleration could very easily be a boost leak. check all silicon hoses. most often the boot from the charge pipe AT the intercooler pops first. check your turbo out. then check your intercooler for leaks.

I'll do that when I get back home, guess I'll just have to drive careful. Everyone I talked to told me I didn't need to worry about fuel pressure, I guess I need to fix that. Would a boost leek affect the idle rpm even out of gear?

absolutly not. you can take the turbo all the intake grid heater ect off and it will idle like brand new. idle quality has something to do with your pump. and the people you have been talking to OBVIOUSLY dont have their money invested in this truck or they would have advised differently. fuel preessure not only feeds the pump but it cools and lubricates it, if you dont have enough, plungers eat themselfs. and a stock pump with 268k on it is wore out.

When I took it into the shop for the "tune up" they told my my throttle linkage was a little rusty and junky so it could be that it has loosened up again. I just hope to god its not a compression issue.

your IP is benched to have X start fuel. a loose linkage will have absolutely no effect on this adjustment. the start fuel linkage is adjusted on the back of the pump with a 10mm wrench. adjusted wrong and it will have to have a bit of go pedal to fire but once fired will not typically effect idling. idle should be aroung 850, you can turn the 10mm stop up a pit and see it that helps. once it starts hard go back the other way. does it spit and crack at you in neutral when you rev it up? if so low fuel pressure look at you lift pump and OFV.

It doesn't stutter when I rev it at all. I had the idle adjusted once before and the idle went down when all this other stuff happened. If there was low fuel psi wouldn't there be less black smoke not more?

yes, one thing at a time. if it doesnt shudder when you rev it up its probably not fuel pressure. check for large boost leaks. split hoses and such. the one i mentioned is common.that same hose can rub on the inner fender as well. givethe charger a good look see.

you said your are having issues with idle in gear and in N? going from P or N to D do you see any rpm drop? you should. is the trans shifting well?

When first started on rare occasions it will studder and need a little peddle, but idles fine after that. That hasn't happened yet with this issue. When I first start it it idles at 7200 (around 8 is proper if i remember) and when put in gear it drops to 6500. When idling and rolling without my foot on the brake it idles a bit higher, but at a stop in D with it in gear it idles at 6500.

im assuming you mean 650rpms? that is about 200rpms to low. adjust that 10mm nut up and see what that does.

Ok so I was off about the idle because there are only 3 slots between 5 to 1 which means 1k should be 9. That's confusing. It's still idling lower than it was though.

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Ok, so i was able to take it out on the highway and really romp on it. Still reaches 35psi. It just doesn't "catch" like it used to, engine winds up going up hills but the torque just isn't there. Really feels like the torque converter, but that wouldnt explain the idle drop. Also I went from Lubbock Texas to Denver, that's an altitude change, would that have anything to do with it posibbly?

a boost leak WILL affect the idle quality, i had about a 2 inch split in mine and wasnt was sucking hard causing my truck to idle at about 400 rpm i put duct tape on it when i found out what i was to get it home it idled right back up, but you shouldnt have a boost leak if you making 35 pounds.

On another Note. The engine does vibrate a little bit in neutral at 1000-1050rpm. And this disappears at 1100-1150. Egts are substantially higher cruising.

Have the timing checked. It is likely to slip with the 4k gov springs.
torque the nut after it is reset to 140-150 lbs.

or to 250lbs

Do you mean the idle nut or 4ksgk

I am referring to the injection pump nut on a p7100 motor. It takes a lot more power to turn it to 4,000 and the stock torque number is too low. This is IF the timing slipped, or needs reset. By the way have them set it to 15-16 BTDC.
Better MPG and power.