Vantastic CNG power

[djbonsu]

Hang in there man, you are almost to the finish line. Did you replace your IPR valave on the rear of the HPOP? If so, is the little tin nut still on there? Do you have a scangauge? Im curious to see what your HPOP pressure is when the truck will not restart. Im thinking something is going on with the HPOP.

 

[JPutnam]

I did replace the IPR on the hpop. the nut is still there. I don't have a scangauge. I need to get one it seems. I did take it to my friends shop and used his fancy gauge a few weeks before taking it in to a diesel shop to be told its low compression. We couldnt get it to shut off when the thing was hooked up. and the oil pressure was reading normal the whole time. that isn't to say that the hpop isn't the problem. we had limited time messing with it. It almost seems like it goes into limp mode or safe mode or something. I don't know.

 

[gtbensley]

Its not the motor.....That would run like crap all the time if it were I bet. I think the shop that said the oil was getting thin and not being thick enough was more on track. But if it were compression related, it would start like crap and run more poor when cold.

I would get it on a computer and check you HPOP PSI as well as duty cycle for the ICP and % being called for. I would imagine if it were the HPOP itself it would not want to start because it was draining down and would thus not start well ever. (although I guess it could be not keeping up with demand hence why it stalls out under load) Again, that comes back to duty cycle on the pump. If the called for amount of oil is not being met it will try to increase output until it is met. I think something over 60% normally means the pump cant keep up. But that could also mean you have a ICP sensor sticking open and not allowing pressure.

 

[JPutnam]

I still haven't gotten this thing fixed yet. I was thinking about it a few weeks ago and reading up on psd 7.3s. early 99 (and 98vans) had cats on the exhaust. 99.5+ ford removed them. I think. I remembered seeing a cat on mine and thought that maybe with all the oil my engine was dumping out the exhaust for who knows how long the cat got clogged or fouled. Driving it at a consistent or higher rpm or getting into boost would make my EGTs spike super high. Im not sure if there is a monitor for that but maybe if that was happening the ecu would go into limp mode until it was cooled down. I know it doesn't have O2 sensors or anything. But it seems like that could potentially be happening.

So I ordered a cat delete pipe for a 94-97 OSB 7.3(since they don't have them for psd 7.3) It came in on Saturday and is a few inches(like 8) too short. So I need to remove the whole exhaust and chop up the cat pipe and weld it together. not a huge deal. just more work. If this doesn't fix the issue I plan on ordering a t500 hpop next weekend. Then if that doesn't fix it I will pay a shop. As always money is tight so I am trying to figure it out.

 

[gtbensley]

These van have no way of monitoring the EGT temps, so it would be a malfunction shutting it down, not a preventative measure from EGT's being too high. Having said that, definitely worth ditching the cat, I did it on mine and the van is much more happy now.

I just took a long section of 3.5 ID pipe and clamped it into place where the cat was, cost like $20 for the whole deal.

Dont put the HPOP on until you get a scanner and do some testing, you may just be throwing money away!!!! Its worth checking your pressures while its running vs when it wont start or cuts out. It could be the HPOP but it could also be many other things.

 

[Bikersmurf]

These van have no way of monitoring the EGT temps, so it would be a malfunction shutting it down, not a preventative measure from EGT's being too high. Having said that, definitely worth ditching the cat, I did it on mine and the van is much more happy now.

I just took a long section of 3.5 ID pipe and clamped it into place where the cat was, cost like $20 for the whole deal.

Dont put the HPOP on until you get a scanner and do some testing, you may just be throwing money away!!!! Its worth checking your pressures while its running vs when it wont start or cuts out. It could be the HPOP but it could also be many other things.

Good to know about the improvement from deleting the CAT. I asked a while back wether I should swap in the CATless exhaust from a 2001 in place of my 1997 exhaust and wasn't able to get a concensus as to wether it would be worthwhile.

Any louder sans CAT?

How is the van happier?

 

[gtbensley]

Its a bit more loud if the windows are down, and you can hear the turbo spool from the exhaust now. I think it sounds good and cant hear any difference with the windows up.

Just feels more responsive and runs cooler. Mine was pretty plugged up when I removed it so it makes sense. The interwebs consensus is it will drop EGT about 100-200 degrees.

 

[kojackJKU]

I had a van the same vintage that did the same thing....never did find out what was causing it....I bought a new truck and sold it for parts!

 

[JPutnam]

I cut out the stock cat and welded up a straight pipe. The flange wasn't the right size so I spent a few hours with a hand file enlarging the holes. Ended up only being able to get 1 nut on it. Kinda gave up on that. I will need to cut the stock flange off the old piece and then weld it back together on the new piece. I didn't take any pics. No surprise that it didn't help at all. Did make the van slightly louder. but the engine is still louder yet. drove it around the block and the same thing happened. So I ordered a T500 Hpop and new gaskets. I took it out 2 Thursdays ago.

shipped it that night and was told it would be there Monday or probably Tuesday. The website claims 17-21 day turn around time so I cant be in too big of a hurry. On Monday morning I got a notice that my package was en route. I ordered it from riffraff diesel. they send my hpop to terminator and terminator modifies it and ships it back to me. So I assumed riffraff was just sending the gaskets. When I got home from work Wednesday I had a package on my porch. Upon opening it I realize its the Hpop. not just any core Hpop. My Hpop that I shipped them.

its a crappy pic. only one I took. but it has the same serial number and all the same scratches and dents. but with the t500 stuff on it.




6 days from me shipping it to them rebuilding it and me receiving it back. threw it back on Thursday and did a test run around the city. had no issues at all. I then went for about a 100 mile drive out to Saltair and then back up to Park City. Was a nice drive with no issues at all. No leaks either. So that's awesome.




Then some kid wanted to trade some of my wheels for this engine he had. claimed all sorts of stuff that aren't true. But I did it anyway. The catch was he lived just outside of St. George a good 350 miles away. Sunday my wife and I packed the van up and took it for a longer trip. I was fairly apprehensive about the trip as I hadn't really tested the van and I could potentially be stranded needing to get the van towed hundreds of miles. But im fairly stupid so I went for it anyway. Ran great. took a bit to start it in Fillmore(about 150miles in) I think it was an air bubble in the oil system. People claim there will be air bubbles in the system for a good 1000 miles or so. But no problems besides that until at the kids house. Had even more trouble starting there. I traded about 2K worth of wheels for about $800 worth of rotary lol. Stopped to get gas a few miles away and was worried it wouldn't start again. But it started right up. and didn't even hesitate the rest of the trip. I really wanted to stop and see places but we didn't leave Salt lake until around noon. With 4 hour drive there and another 4 hour drive back we were chasing daylight. My wife did want to stop and see the volcano outside of ST. George. Both of us were unimpressed. I have grandparents and family that live in St. George. I am still blown away that anyone would want to live there. Maybe its because I am colorblind and cant tell the red rock from the brown rock. It all just looks like a desert to me and ITS HOT. ALWAYS.

(that's the volcano behind the van.)

We then took the back way to Cedar city(on the way home) and stopped by old Iron town. There were a bunch of houses right next to all the ruins. so it wasn't that neat.

Did drive this road though.

Here is the behive iron smelter thing(I cant remember what it was called) behind us.

then had an uneventful drive home arriving around midnight.