I just bought a truck that the previous owner had a new injector pump installed on. It is a 98 model and has FASS lift pump with 1/2" line kit and 100HP injectors. It has rock solid pressure at 14psi, and was setup like this when the first pump failed. The VP44 was replaced and two weeks later started having dead pedal and had the 216 code. The shop told him he got bad fuel and they would not warranty it.

Fast forward two years; the truck has sat and been driven only off and on since the pump issue. I bought it today, and I was planning on just putting another pump on.

However, I read just now before ordering a pump that some folks have trouble after the pump install with the 216 code due to improper key installation. My question is on how to check this. Is there a tale tale sign that will be noticable if I just pull the cover and look at the key? It also said it could have been damaged on installation causing the problem. If I can not see anything, what damage would I be looking for when I pull the pump?

I will also add that the truck starts perfect and runs perfect when the pedal is not dead. The dead pedal will come and go until it gets warm and then will work a while fine....then might do it out of the blue. There is no smoke except a puff on acceleration or any other symptoms.

If there is anything else to check before buying a pump, please let me know.

 

How is the cam sensor doing? Has it been checked? The one under the VP-44.

The key would have visible damage to it upon inspection, no? But that means changing it out so you can have a look at it.

 

I found a new issue that has to be solved first. After driving the truck a little I found that once the dead pedal goes away, fuel pressure drops to nothing when you stand on it. It has a bad battery that has to be replaced(load tested 6A) as well. I know that a battery with plates shorted can cause all kinds of issues, so that is the first move. We're gonna do the battery, filters and check the bypass valve on the pump in hopes that by some miracle that will fix it.

As for the cam sensor, I dont really know how to check that. I had the codes pulled and there is nothing suggesting a sensor failure.

We will pull the pump and check the keyway if the battery and lift pump issue fix does not help. If the keyway is good, I guess I will order a pump.

 

Perhaps shop may be using the "bad fuel" as an excuse not to warranty. MWFI stood behind my 1st VP install and called my vendor to warn of "gas in the fuel" & not to drive. 25 gal of fuel went to the dump. 2nd pump threw a 216 code. I cleared codes & loaded tank with Stanadyne Lubricity & have been fine since (< 10,000 mi).

My logic is that something in the pump was sticking. I haven't taken a VP apart but have read about a piston/valving. Have also read about people using 2 stroke oil for lubricity. You'll have to do your own lubricity research. I'll stick with the stanadyne because I can buy locally & have read where it does have measurable effect. It is also less expensive than 2 stroke per dose. Just google for the lubricity study.

 

Be sure to check all your fuel line connections for the FASS. You could be sucking air through a loose fitting and a little bit of air will cause that timing piston in the VP to vibrate and will probably cause a 216 code.

 

Thanks, that makes sense.

 

I actually run two stoke in my other VP44. I have a couple quarts in the tool box I am gonna dump in this other one for giggles.

 

what about the fuel filter? fuel pressure dropping 0 is a filter problem!!! it should never drop to 0..or less..yes I have see less. has the fuel pickup in the tank been cleaned? I was recently having problems with my fuel pressure..drop the tank and check the intake..what a mess of dirt..1/2 a can of brake cleaner and I finally found the fine screen at the bottom..been fine since I found the leaking factory filter housing.

if you can put your hands on some biodiesel is better the 2 stroke oil. check the lubricity test results..biodiesel is one of the best.

have you checked you APPS?

-dkenny

 

I think IF I had bad fuel, it was the B20 that I bought 1/2 tank of. Bad news when you can't just pump & not worry. I'm considering a 12V to go with my 85 300SD. The Cummins 12V & Mercedes 617 are 2 of the best engines made.

 

Yeah filters are being changed. I changed the battery and that did not help. However, I did noticed that pressure drops a couple lbs just when the heaters kick on. Will see what happens with new filters. My brother was working on that when I left, so should know something tonight.

I dont know anyone with biodiesel in my area. I do have a copy of the lub test, and the two stroke oil had a big improvement at 200:1. I put it in about double that for the first test. Did a test drive with this and the battery with no change. Still had dead pedal that cleared up once temp gets up just a little bit.

One thing that seemed to not make sense to me is that just kicking on the heaters drops fuel pressure. If voltage is dropping that low it is also dropping voltage to ECU and all sensors. I know that electronics act funny with low voltage. That would also follow with dead pedal going away after temperature starts to come up.....something is amiss there I think, but I am gonna have to get a voltmeter out to learn what.

 

Agreed on the 12V.

 

Update:

Both fuel filters are changed. We ran the truck just pulling from a bucket to eliminate draw straw or in-tank strainer issues. The fuel pressure is still bad. The FASS will only make 12psi at idle and the blip of the throttle immediately drops it to 6psi. WOT run will drop it to 3-1psi.

Thermostat is stuck so the engine warmup is very slow. This is causing the grid heaters to run more than they should. INTERESTING NOTE: When the grid heaters stop cylcling dead pedal seems to stop...sortof confirms thoughts on voltage drop issues.

With dead pedal I noticed that I can be cruising at 70mph and holding speed no issues. Then I try to accelerate and the pedal is dead and starts dropping speed slowly. It is not like when the pedal is dead from a stand still because untill I move the pedal it is fine. Also, the pedal will come back in a second or less some times. Sometimes it takes 5 seconds and sometimes it will not reset at all. The long reset is at slow speed with heaters cycling.

Is this normal dead pedal activity?

 

Sounds pretty much like what mine did when the first pump was failing. Usually letting off the throttle then getting back into it would solve it for a few more miles until it did it again! Have you tried disconnecting the grids and rechecking fuel press? I'm not sure whether to think you have a bad motor or electrical connection on the FASS or a problem somewhere in the truck electrical (batteries, cables, bad ground). Also, the grids should shut off at around 15 mph if I remember right, so any deal pedal/fuel press issues above that speed should be unrelated to voltage drop from them. Did you change only the one battery? It is usually not a good idea to change only one, you may still be having issues with the old battery. I have personally had problems with batteries that have load tested fine. These trucks are SUPER picky when it comes to having a good clean supply of voltage, believe me, I have chased my fair share of issues on my truck only to come back to good batteries and clean grounds!

 

Wow, sounds like a real pain of a problem to chase down. Good luck with it. Think my 12v needs a hug

 

haha....yeah, and maybe a little pinch on the rocker cover . My old 12V would run with one dead battery, a zip tie on the fuel shutoff, and half veggie oil(like out of the jug from the cupboard....true story) and diesel if I was too low leaving the house to get back to town.

These 24V's are like a pretty little princess with a stale crumpet