Troubleshooting Help/Suggestions

Hotrodtractor · Aug 4, 2011

Ok guys - I'm tired, frustrated, and thats not a good combination. Here is the deal:

I have a truck in the shop with a 15 degree oil pump and a Gen3 style pump - the pumps are feeding 400/200 hybrids. There is a pull on Saturday that this truck MUST make. The truck will build ICP like a champ - then it will drop to about 800psi and be a gutless wonder.

Through troubleshooting - I ended up pulling the injectors because of a known issue we had - plus some irregularities I ran across - known issue was fixed with no problems and the injectors checked out great on the bench.

Went through some more looking around after the injectors were reinstalled - and decided I had an issue with the Gen3 pump - I pulled the pump, found a bad front seal - ended up getting a new pump (and reversed the rotation) because of the deadline and didn't want to take any chances. The truck now starts and idles GREAT - it had a bit of a rough idle before that I still can't totally explain...

Take it for a road test and it launches great - and then falls on its face at 800psi still.

The truck idles at the 650-700psi range at 10-11% duty cycle - with the bad seal the duty cycle would never go lower - with the new pump the duty cycle will decrease as the truck is free revving.

I'll be pulling the IPR again and I'm going to check the pop off valve in the 15 degree pump just to check things out.

WTF am I missing? I'm tired, stressed, and pissed. Its an all around bad combo and I am looking for ideas. Off to bed - someone please tell me what stupid little thing I am overlooking.

Thanks.

TARM · Aug 5, 2011

The very first thing that came to mind was the pop off valve. Thats a huge pressure drop. I take it what the ICP is actually calling vs actual for has been checked to rule that out.

It seems from what you have listed for events that the issue has been common even after the gen 3 swap out so I also would be looking at the 15 degree pump given its the common link.

What pressures is it hitting before it tanks?
Has this pressure it reaches been consistent since this issue started?

You could look at the actual voltage going to the IPR during a run as well. That may show something or rule out that part. Just swap out the IPRs with all new orings just to be sure and test to make sure its clicking open and closed when 12 volts is applied.

Honestly though the way its just dropping off brings me back to the pop off valve.

Actually as you already know the best thing you can of done was to do what you did but likely a few hours sooner. Just step away from it and get a good nights sleep and come fresh at in the morning but wait until you are good and fully awake with some food in your belly.

If it would be of any help I will pull my dual stealths off my truck and overnight them to you if need be. It needs one new IPR or oring but thats all.

Hotrodtractor · Aug 5, 2011

I have a data log that gets up into the high 2Kpsi range before it tanks - and it tanks fast.

I would say that as far as I know - yes the pressure it spikes to has been consistent.

I agree that the 15 degree pump seems to be the only constant - but I keep bringing myself back to the fact that this think starts and fires up like a champ. I guess I just can't see the pump itself being the issue because of how fast it does build pressure while cranking. I'm not opposed to swapping pumps at all to test that theory.

The truck ran fine - then it didn't - through the course of this there was also an oil leak "in the valley" area that I have been fighting - I found on on a Gen3 fitting - and it seams as if I have one on between the front cover and the Gen3 housing.

I'm going to swap to a known good IPR. I already checked the harness with a meter as well as the IRP signal with a scope - it seamed OK to me.

I agree - I've been thinking its the pop off valve. I'm wondering if it didn't have some sort of horrendous pressure spike that blew the front seal of the Gen3 and screwed up the pop off valve at the same time.... it makes me want to take a much closer look at that IPR when I get home from work as well.

TARM · Aug 5, 2011

So IPR signal was good. I would think that you would see it go up to a full 12 volts at the time it started to tank as the ICP would be calling for 2K-3K yet the pressure would be dropping so it would be closing the ipr to fully closed and max duty cycle.

I think you are doing all you can by checking the pop off and replacing the IPR. Only thing left would be to swap out that pump as well.

vanderchevy18 · Aug 5, 2011

If I had a spare pump I'd send it to you but they're both gone as cores for a couple srp-1's. I would swap out that 15* first thing. Everything I see points to the psv as well.

Hotrodtractor · Aug 6, 2011

I took the shotgun repair method to it. It got a used 17* pump and IPR - the problems all seem resolved tonight... going to change the oil tomorrow morning and test drive it in the daylight. I am sure the neighbors love the sound of an S400 spooling up with loose converter in second gear off the line at 11:00pm. She seems to be holding 2800psi now no problem.

TARM · Aug 6, 2011

Very good. So what ever it was is in the 15 degree pump or its IPR. Be interesting to know what the problem actually was but you were on a time schedule not to mention limited sleep time LOL

Hotrodtractor · Aug 6, 2011

TARM said:
Very good. So what ever it was is in the 15 degree pump or its IPR. Be interesting to know what the problem actually was but you were on a time schedule not to mention limited sleep time LOL

Yeah it kind of bothers me that I didn't narrow it down any further - but in all reality it wouldn't have gained me anything to narrow it down. I'm headed to shop to change the oil and test drive it again. It should run a whole lot better with some straight 50 weight Cenpeco racing oil instead of that thin as hell crap that is in it now.

Yodersstrokin96 · Aug 6, 2011

glad ya go it figured out!!

TARM · Aug 6, 2011

Hotrodtractor said:
Yeah it kind of bothers me that I didn't narrow it down any further - but in all reality it wouldn't have gained me anything to narrow it down. I'm headed to shop to change the oil and test drive it again. It should run a whole lot better with some straight 50 weight Cenpeco racing oil instead of that thin as hell crap that is in it now.

Yes sometimes it just not worth it even though by nature I like to know the cause and resolution. Let us know how it runs once you get a chance to take it for a test run.

About the oil viscosity I understand how it would raise pressure. But would it not be at the cost of flow velocity? Wouldn't the increased flow velocity allow for faster filling and emptying of the injector as well as flow thru the rails? Is there a tipping point where there is an ideal balance point that you have found. Or if I am thinking about this incorrectly when you have some time could you explain it?

Hotrodtractor · Aug 7, 2011

TARM said:
Yes sometimes it just not worth it even though by nature I like to know the cause and resolution. Let us know how it runs once you get a chance to take it for a test run.

About the oil viscosity I understand how it would raise pressure. But would it not be at the cost of flow velocity? Wouldn't the increased flow velocity allow for faster filling and emptying of the injector as well as flow thru the rails? Is there a tipping point where there is an ideal balance point that you have found. Or if I am thinking about this incorrectly when you have some time could you explain it?

It ran fantastic on the test run yesterday morning!

Last night the truck driver piloted the truck down the sled pulling track and was happy with how it ran - I spoke with the family and said that it seemed pretty soft off the line and kind of loafed down the track - Their answer - make me pull it in the 3.0 turbo class. I hooked it up, tightened the chain, and did one of my HRT style - I'm going to take this sled home with me launches - it launched great - shifted into 3rd using the PCS bump shifter - and then..... It bounced so hard the rear view mirror came of and hit me! I got out of it enough to smooth it out, got a bit under the charger - downshifted back to second and let it eat right up until the bouncing started again - when I decided my kidneys they had had enough. I guess there is a video - and it was commented that I had all 4 wheels off the ground at one point. It allowed me to once again start up the suspension conversation with the owners. This thing is a beast if you can put the power to the ground.

JD3020 · Aug 7, 2011

Did you pull in Urbana last night? And is it another COTPC truck?

Hotrodtractor · Aug 7, 2011

JD3020 said:
Did you pull in Urbana last night? And is it another COTPC truck?

Yes on both accounts.

Hotrodtractor · Aug 7, 2011

JD3020 said:
Did you pull in Urbana last night? And is it another COTPC truck?

In other news - I saw the first run of a brand new SIGMA powered PSD at Urbana last night. Very solid first run. I didn't get a chance to see the second run as that was right after I hooked and I had some things to take care of. I'll get Nick and Drew over here on PSA to talk about it at some point.

JD3020 · Aug 7, 2011

Hotrodtractor said:
In other news - I saw the first run of a brand new SIGMA powered PSD at Urbana last night. Very solid first run. I didn't get a chance to see the second run as that was right after I hooked and I had some things to take care of. I'll get Nick and Drew over here on PSA to talk about it at some point.

:cursing::cursing::cursing:

I was about ready to hop in my dad's truck and drive up to Urbana cause i wanted to go to the pulls bad. But nobody wanted to go and i didn't wanna go up by myself. So i stayed home and worked on the farm, then later found out my brother went. I guess i'll have to go to WCH or London to watch some pulls.

I really wish we could get COTPC to pull in Eaton. I don't think i've seen a single PSD pull here. We get a bunch of the big D-max and Cummins guys but other than the p-pumped 7.3 last year i haven't seen a competitive Ford here.

TARM · Aug 7, 2011

Hotrodtractor said:
It ran fantastic on the test run yesterday morning!

Last night the truck driver piloted the truck down the sled pulling track and was happy with how it ran - I spoke with the family and said that it seemed pretty soft off the line and kind of loafed down the track - Their answer - make me pull it in the 3.0 turbo class. I hooked it up, tightened the chain, and did one of my HRT style - I'm going to take this sled home with me launches - it launched great - shifted into 3rd using the PCS bump shifter - and then..... It bounced so hard the rear view mirror came of and hit me! I got out of it enough to smooth it out, got a bit under the charger - downshifted back to second and let it eat right up until the bouncing started again - when I decided my kidneys they had had enough. I guess there is a video - and it was commented that I had all 4 wheels off the ground at one point. It allowed me to once again start up the suspension conversation with the owners. This thing is a beast if you can put the power to the ground.

:redspotdance::redspotdance::redspotdance: that is awesome. Its always great when something works out the way you want. When it all comes together things are sweet!!! Glad it went so well and you had a chance to make it chew some dirt HRT style LOL

NyCowboy87 · Aug 8, 2011

Jason, did this truck do it EVERY time you/the owner got into it or was it sort of intermitent. I have a similiar issue with mine and its bugging me. I highly doubt there is an issue with my injectors as they were newly built as of May this year. In attemps to figure it out yesterday I beat the heck out of it on the street got it to do it once right off the bat then couldnt get it to do it again.