Engine/Transmission (1998.5 - 2002) Electrical or Mechanical???????

[Bowden]

I have been searching these forums for hours with no luck for a solution so any help will be much appreciated. My truck is a 00 automatic Quad Cab with 172,000 miles. It was losing coolant out the exhaust and in the crankcase so last weekend I replaced the head gasket. Everything was uneventful until I tried to crank the truck. After bleeding the system, it cranked but idles rough and is very slow to accelerate up to a max. of 2500 rpms in park or neutral. When in any gear, it will not accelerate at all like the pedal is not even hooked up. I have loosened all fuel lines at the head and a difference can be heard at each cylinder. I did break the MAP sensor while cleaning the head before installation but have replaced with a new one. I have reset the APPS twice with no change. I have removed the IAT sensor, cleaned and reinstalled. I have cleaned the electrical connections for these sensors as well. It is throwing no codes using the key method or a scan tool. The truck is stock with no mods except for fuel, EGT, and boost gauges. Fuel pressure is 12. 5 psi at idle. The VP44 was replaced in 08 but has had very few miles put on it since then. I should mention the truck was running perfect before the head gasket change. Any ideas?

 

[AEdelheit]

I'd guess electrical, triple check any grounds or connectors that were unplugged when removing the head. Did you make sure all the valves were adjusted properly too ?

 

[cerberusiam]

Cross over tubes leaking or not seated? Did you replace o-rings, check mating, and TQ correctly?

 

[Bowden]

I did not adjust the valves and I did not remove the injectors. I have been concerned the injectors might be the problem as far as the rough idle but cannot see how that would make the pedal go dead when the transmission is put in gear. Is there any way this could be caused by the MAP sensor or IAT sensor? I put a new MAP sensor in but it was from O'Reilly's and I can't help but question it.

 

[cerberusiam]

You removed the lines from the IP to the head. That may have caused the cross over tubes to come loose and not get seated correctly again.



You need to run the valves and make sure they are correect also. You likely changed the setting with the gasket.

 

[Bowden]

Ok, that makes sense and doesn't cost anything! Would that also explain the pedal issue? Will extreme low power cause the pedal to stop working only in gear? I will check the tubes and adjust the valves but I'm just curious about the pedal. Thanks for the helpful info!

 

[NIsaacs]

Did you find the water leak culprit when you changed out the head gasket? Is it possible it is a cracked head and the new gasket/head torque disturbed/made the crack larger and it is trying to burn water? Or the turbo is sized up because of it? Your valves definitely need adjusted.



Nick

 

[Bowden]

I did not see anything obvious with the head gasket but since putting it back together I have let it idle long enough to get to 190 degrees and start circulating coolant. There is no sign of coolant in the oil or loss of coolant. Before the gasket change the loss was considerable. The turbo will spin freely by hand so it is not seized up.

 

[Bowden]

I adjusted the valves last night and found they were all on the loose side but were within tolerance. I guess the next step will be pulling the injectors and having them tested. I'm afraid I could have damaged the nozzles while the head was off. Through all of this, I found the source of my coolant leak that I thought was fixed. I saw a small round circle of coolant in the puddled oil on top of the head last night. There was a freeze plug under it with a pin hole in it. As soon as I touched it my finger went right through it. All of this over a pin hole in a freeze plug! It does have me worried about all the other freeze plugs in the engine though.

 

[NIsaacs]

On one hand at least you found the source of the leak, but like you said it is a bad sign and I feel your pain, there are several soft plugs behind the tappet cover. That would explain the coolant in the oil but not the coolant in the exhaust.



Nick

 

[Bowden]

Any suggestions on which injectors to buy? The truck is bone stock so will the 50hp injectors work with no problem or are more upgrades needed? Can I just replace the nozzles or is it better to just buy the whole injector with the nozzle? Price? Quality? Sorry for so many questions I just want to make sure I get it right the first time! Thanks guys for all the help.

 

[JLandry]

Any suggestions on which injectors to buy? The truck is bone stock so will the 50hp injectors work with no problem or are more upgrades needed? Can I just replace the nozzles or is it better to just buy the whole injector with the nozzle? Price? Quality? Sorry for so many questions I just want to make sure I get it right the first time! Thanks guys for all the help.

They say you can't beat good ol' genuine Bosch RV275 injectors for a mild upgrade on a stock engine. Everyone swears by 'em.



If you decide to replace just the nozzles, I wouldn't recommend doing this yourself (I couldn't tell if that's what you were thinking) without access to a pop tester and spare shims to ctually adjust the pop pressure. Without that you risk having a rough idle due to a pop pressure variation from injector to injector... or worse.



Without a pop tester you'll need to send them off to someone to have the injectors cleaned, then new nozzles installed, and pop pressures adjusted. By the time you're done buying the nozzles, shipping the injectors to and from a shop, and then paying for the work, it'd probably cost less to simply buy new injectors outright.



Best regards,



John L.

 

[NIsaacs]

Since any performance injector for the 24v needs a little help in the way of a boostfooler at minimum, like John said, the RV 275 is a good way to go. Team them with any of the mild power box's and you will have the boost elbow and boost fooling built in. Awesome combo.



Nick

 

[TPringle]

Since the engine ran ok before you pulled the head, I'd hold on the injectors until you check some other stuff. I cant imagine damaging all 6 at the same time! They cost money. Crossover tubes have been mentioned. Did you have the lift pump off? Could the studs holding the lift pump to the bracket been loosened allowing air to enter (looks like they could be loosened when the nuts are removed)? Could the return line be kinked or pinched behind the head? Could you have stirred up some crud in the filter when removed from the head? - which is now in the VP? Could the wires to the APPS have been pinched or cut?



Bluechipdiesel.com has some excellent reading on diagnosing problems with the APPS and VP. You can fire the engine without the computer to see how it idles, to eliminate something electrical that can be "telling" it to mess up. Info on how to check the APPS also. Is the wastegate ok on the turbo? Throwing you some ideas - just my . 02.

 

[Vaughn MacKenzie]

I think a ground got disconnected somewhere because something like that happened on my '01. The idle was erratic and very low power, found the loose ground and presto! power came back. It was one of the connections by the battery on the passenger side I had undone. Grounds are way important on these electronic engines.