Funky Starting after injector install

[Joe Mc]

A bit of info first. In July this year I sent my Mach 5 injectors back to Don for a freshen up. Bought new from Don's (F1 Injection now FDI) years and at least 100k ago and truck was hazing more at idle than I liked, but otherwise running pretty good, so figured they needed a once over. In conversation with April she asked if I wanted them to be taken up to the next size. I asked her that I figured the nozzle holes would have to be all taken out to whatever the biggest hole was it would probably be easiest for them to just go next size up. Yes, $600, I was fine with that.
1st week of Sept I returned from a one month trip (I left before injectors arrived) and I get them installed and it sounded great. Took it out for a ride and a little power run after all temps were up to normal and it ran strong. On the way home (about 5 miles after power run) I hit a red light, I always put trans in "N" when at a light and then in "D" when green, so light turns green put trans in "D" and the idle abruptly dropped and then just as abruptly rose to steady rpm? I'm like WTF it never (and I do mean never, ever, ever) did that before with any injectors I had and I've had only F1's. I arrive home, always back into the drive way and "always" place trans in "N" versus just going from "D to R" or "R to D" for a few seconds, so I go from "D" to "N" then into "R" it stumbled (idle dropped, wasn't paying attention to Tach) a second and then stalled. I'm really like WTF here? I sent April email describing what happened and my "D to N to R" and "N" at a stoplight practices, making sure it was understood that my truck never surged going from gear to N or visa versa or just stalled before, offered to send video. She replied that Don said 99% chance one of the tubes might not be seating with injector correctly and to loosen everything up then re torque, of course following sequence in FSM, no mention of my offer to send video. And recommended checking valve lash, which I had already done upon initial install since I was there it made sense. I did and no change. Let April know and again offered to send a video clip. Next reply was, in the past we've seen a weak pump or tight torque converter cause this. She also said "not saying that's the problem, but has been problem for guys in the past", and no mention of offer to send video. I'm like nah, no way. I replied that I could imagine a weak pump or tight torque converter might cause that but my VP was not original I replace a few years back with Bosch Certified (from Thoroughbred), had Walbro pusher pump, big line kit 2 filters and the DTT Trans has not given any problems. Said I'd check electrical connections and so forth. So now we're in mid-Sept At some point April suggested possibly a tube o-ring failed, split or became damaged. I ordered new o-rings, and installed, no change. April said the only way they could rule out the injectors being the issue was to build a new set. In hindsight I should have taken her up on that... But told her I appreciated the offer and was going to order new tube kit and all seals then try that first. Well I did get all the parts and then, life got in the way = getting my home ready to sell looking for new... End of Sept I let April know what was going on (with life), I didn't have to drive the truck and didn't plan on doing so till issue resolved, and that I would keep them posted. So the truck has pretty much sat, I'd take it for a short drive every week or so to bring up to temp and such then put her away for a bit.

Then a few weeks back (after sitting for only 2 or 3 days) I went thru normal start up sequence and it started with a "rump, rump, rump" almost like there was air in the fuel for 5 seconds or so and never settled in to idle then just died? And, once again, it "never" did this before "all this started immediately after installing the rebuilt sticks". Before I even sent the stick for refreshing it had sat for well over 2 months, batteries disconnected, while replacing the rocker panel and when I hooked up the batteries it fired right up like I had just driven it the night before... This Friday (12/11) I took her for a little trip (an hour drive) to visit an old shipmate of mine, figured she needed a bit of a run (PA Tpk 70 mph speed limit) she ran like a top (proud papa), I arrived at his place and go to back into parking spot...yep just stumbled once then died when I went from N to R (embarrassing and really frustrating). I didn't drive it again till I was ready to come home today (12/13) and it did the whole rump, rump, die at start up. I'm like s_it! I wasn't able to get it on video. So I figured "maybe" if I try again and I did, notice after rumping a few times I hit the go pedal and, well you'll see.

Sorry for long "bit of info first" lead in, now you can watch video.



What the heck is going on here??? Help? Any logical ideas welcome.

 

[NIsaacs]

Sounds like it is getting some air in the fuel system. The point is, where?

When you changed injectors, what all did you do/touch with the fuel system at the same time? Fuel filter change? How/where did you bleed the air on first start? Does fuel tank level make any difference? At anytime, did you use the fuel canister drain valve? They can be problematic as they age. Have you ever changed it for a new one? If not, I would start there, with a new one.

https://www.genosgarage.com/product/gg-9799dv/fuel-system-accessories-replacement-parts

 

[Joe Mc]

Removed; rocker cover, hp line nuts, whatever hp line hold downs needed to move lines enough to remove tubes (after wackiness I at one point installed new o-rings on tubes), IJ bridge/hold downs. All the things you'd have to do to R & R sticks.
It does seem like air is somehow getting in system/fuel leaking at stick areas. I've changed sticks at least 5 times over the years but I "always" follow FSM to be sure I'm not missing something. If necessary, and usually is, I crack 2 of the easiest to get at hp line nuts. I have Walbro pump and two filters on frame below tank.
I know initial post is long, but read it and note I installed back in Sept. and this wacky stuff has been going on for some time. I'm wondering if the stick to head seals (new) are not seating properly/not thick enough?

 

[NIsaacs]

I know initial post is long, but read it and note I installed back in Sept. and this wacky stuff has been going on for some time.

Yes, I read the entire post. Did you read mine? You didn't answer my questions. Forget the injectors and connector tubes for a bit. Lets assume they are okay for now. Sometimes it is hard to see the forest for the trees.

Again, think back. What did you do, fix, disturb, use or mess with, in anyway, with the low pressure side of your fuel system?

 

[DavidC]

I knew I have heard that start up before and couldn't place it. Mine would do it after replacing the filter until the air was purged but it was always a hard start also. Joe's sounds like it fires right off. You may have already stated it but how is the fuel pump pressure during all of this ?. There was a time when my lift pump was intermittent and I joggled a large plug near the firewall on the drivers side and has been good for a few years now. It does sound like it is starving for fuel tho.

 

[petersonj]

A bit of info first. In July this year I sent my Mach 5 injectors back to Don for a freshen up. Bought new from Don's (F1 Injection now FDI) years and at least 100k ago and truck was hazing more at idle than I liked, but otherwise running pretty good, so figured they needed a once over. In conversation with April she asked if I wanted them to be taken up to the next size. I asked her that I figured the nozzle holes would have to be all taken out to whatever the biggest hole was it would probably be easiest for them to just go next size up. Yes, $600, I was fine with that.

My first question is, "How much larger than stock injectors are these Mach 5 injectors with one size larger nozzle holes?" The reason I ask is because from my understanding, the ECM does not receive any input form the APPS during engine idle. This would mean that the ECM would be controlling the VP44 fuel delivery within narrow fueling parameters based on stock injectors with stock nozzles. It would seem reasonable to me that large nozzles could cause the ECM to hunt when engine load is changed at idle. When the engine load is changed (especially when increased) at idle the ECM will respond with its stock injector fuel command, but with large injector nozzles too much fuel will be injected, consequently the ECM shuts off the fuel and the hunting starts, or the engine dies.

I don't think you have a problem with air in the system, although it can't be ruled out. Your symptoms seem to be too consistent for that.

If you shift your transmission from reverse to drive (or vice-versa) without the pause in neutral, does the hunting begin or the engine die? My guess is that neither happens because the engine load would not change much.

So, with the minor differences in ECM's, VP44 injections pumps, and torque converter stall speeds, I don't think you should rule out that the upsizing of your injector nozzles could be triggering the symptoms you are experiencing.

- John

 

[Chief USA]

I am NO MEAN an expert in this area and I am following this thread for my own information as I have F1 injectors installed in my truck as well. Once the F1 injectors were installed I immediately noted an idle lope very similar to yours Joe, just not as bad. The idle lope occurs when I am idling along in 1st gear with my foot off of the accelerator pedal or when releasing the clutch with the transmission in gear to back up or leisurely start from a stop in 1st or 2nd gear.

The idle lope has been this way ever since installing the F1 injectors but it has never been a problem for me. I always thought the lope was caused by the VP-44's inability to compensate well for a large or sudden change in fuel demand. I purchased my F1's from a friend who used them in an engine that was used for competition drag racing. I am not for absolute sure they are Mach 1.6 injectors as these injectors cause notable issues with smoke control during low boost/high demand situations. Aside from the idle lope and smoke issues, I am very satisfied with them and they were a BIG step up in performance over the stock injectors.

Not sure if I have helped or contributed to this discussion but there seem to be some similarities only I have an NV5600 transmission.

Have you tried starting the engine with your foot every so slightly on the accelerator pedal just barley enough to hold it off the stop, just barely above idle? How does the engine behave then?

 

[Joe Mc]

NIsaacs, See answers to your questions. Thanks

Sounds like it is getting some air in the fuel system Yes Sounds like it. The point is, where? Indeed

When you changed injectors, what all did you do/touch with the fuel system at the same time? See Post#3 Fuel filter change? Yes How/where did you bleed the air on first start? See Post#3 Does fuel tank level make any difference? No At anytime, did you use the fuel canister drain valve? Doesn't have They can be problematic as they age. Have you ever changed it for a new one? N/A If not, I would start there, with a new one.

https://www.genosgarage.com/product/gg-9799dv/fuel-system-accessories-replacement-parts[/QUOTE]

 

[Joe Mc]

DavidC -You may have already stated it but how is the fuel pump pressure during all of this ? Didn't state but in first few frames of video it shows 10psi, assuming you are referring to VP inlet pressure via walbro pusher pump and not VP. It runs the typical 5 or so seconds when you tun the key to on while waiting for "Wait to Start" to go out, once up and running it's 20. I know "what? 20#! Are you sure"? Yes checked with mechanical gage at Tee between pusher to VP line and I set regulator at that psi as I read here long ago that the VP doesn't like more than 22.5#. Been this way for many, many years, since then and at present it "never" drops regardless of throttle position or Comp Box setting = Rock Steady at 20#.

petersonj -How much larger than stock injectors are these Mach 5 injectors with one size larger nozzle holes?" Not sure how much bigger than stock the Mach5's are but they're 200 hp sticks so the next size up would be Mach6 @ 220 hp. I get what your saying with the whole APPS, ECM & VP statements, but the Mach 5's were in there since the Spring Fling in 07 and had around 100k+ miles on them they "never" did what's going on now. I doubt 20 hp more sticks would cause the APPS, ECM & VP to all of the sudden start saying "OK, I think we'll just start f-ing with Joe now" LOL
-If you shift your transmission from reverse to drive (or vice-versa) without the pause in neutral, does the hunting begin or the engine die? My guess is that neither happens because the engine load would not change much. Not much change when I do R to D, or D to R, but a very noticeable and immediate idle down/up (higher than when in gear) and then back to as it was before - all this happens in like a split second.
-So, with the minor differences in ECM's, VP44 injections pumps, and torque converter stall speeds, I don't think you should rule out that the upsizing of your injector nozzles could be triggering the symptoms you are experiencing. I'm not buying it, not saying you are wrong or it isn't possible, just saying doesn't make sense that 20 hp more sticks and at idle would do the stall thing. And, the whole "rump, rump, rump" as in the video at start up is exactly how, when after installing new sticks and the air is just about clear and it almost starts or starts and you have to help it with throttle a bit. Not sure that anyone can tell but when I moved the phone away from the Tach I put my hand on the throttle pedal to help it stay running = then in the video it settled in to idle.

CHIEF USA -1.6's are an 85 hp add over stock and the 1st set of F1 sticks I purchased prior to adding HTT turbo and the 5's. I don't recall the 1.6s with the stock turbo making any noticeable smoke change, unless the Edge Comp was set to 5/5. So I'm guessing what you got wasn't exactly 1.6's but who's to know for sure?
- Haven't tried foot on pedal while starting. The thing I guess I didn't mention is "it doesn't always start with the rumping" most often it just fires up like normal. It really seems to me like fuel is leaking from the sticks or air getting in somehow?

Thanks to all who've replied. Your questions were welcome and interesting and I'm sure they will be helpful to me and others who might read the whole post and something will pop in their mind (or based on my answers - your's) and it'll all make sense.

At this point I'm seriously considering just getting a new set of the 5's (like I had) and returning the one's that were refreshed and up'ed to 6's. Thing is, I'm awaiting a closing date on new joint and won't know when I can get to truck to work on "because" I'll need it to help with the move. It still runs darned good it's just the D to N to R & visa versa "and" the interment rumpyness at start up that's got me.

Thanks again folks.

 

[TFucili]

Put a Detroit 6-71 sticker on the fender, and it'll be normal

 

[DavidC]

Keep an eye on your oil, just in case you have one or more leaky injectors.

 

[NIsaacs]

Put a Detroit 6-71 sticker on the fender, and it'll be normal

He didn't say it leaked oil

 

[DavidC]

He didn't say it leaked oil

That's an easy fix

 

[petersonj]

I get what your saying with the whole APPS, ECM & VP statements,

Just to clarify - my statement is

from my understanding, the ECM does not receive any input form the APPS during engine idle.

and,

So, with the minor differences in ECM's, VP44 injections pumps, and torque converter stall speeds, I don't think you should rule out that the upsizing of your injector nozzles could be triggering the symptoms you are experiencing.

I really understand your frustration here. Nothing like installing new components on your truck and being meticulous with your work just to have some weird problem pop up that doesn't make sense.

Have you tried @CHIEF USA 's suggestion?

Have you tried starting the engine with your foot every so slightly on the accelerator pedal just barley enough to hold it off the stop, just barely above idle? How does the engine behave then?

By doing this test the APPS signal to the ECM would be activated and the idle validation switch would be turned off.

- John

 

[Joe Mc]

DavidC - thanks. I check oil level and every other fluids at each fuel up. Most recently (Thursday) engine was about ⅛" below full mark. It's a little past due for an oil change. Paying close attention to engine oil level with what's going on now.

John -haven't tried CHIEF USA's suggestion yet but will next time I start it. And thanks for clarifying.

Note: with engine running, plastic cover off where throttle linkage etc. is I noticed I can move throttle lever open about ⅜" before any change in RPM, is this normal? I also recall reading idle screw/stop isn't to be touched = present leave alone.

Thanks guys

 

[petersonj]

Note: with engine running, plastic cover off where throttle linkage etc. is I noticed I can move throttle lever open about ⅜" before any change in RPM, is this normal?

Yes, this is normal. The bit of free play ensures that idle validation is always set when you release the throttle pedal.

- John

 

[NIsaacs]

At anytime, did you use the fuel canister drain valve? Doesn't have

[/QUOTE]


Okay, no oem fuel filter canister. Does a '99 have codes? Have you tried all settings on the comp?

 

[Joe Mc]

Does it regardless of comp settings, if off and even if unplugged. Can't read codes on digital mileage display with key trick, use code reader. Yes 99 will throw codes. Which there are none presently
John thanks for reply and clearing that up for me.
Really appreciate all the replies.
All this starting immediately upon install of refreshed sticks just doesn't make sense that it's something other than the sticks. Just can't imagine what "in" them could cause what's happening. I'm really leaning towards taking April & Don up on building me new 5's and returning the refreshed ones. If that doesn't return things to normal at least I'll know its something else and then I'll really get to go crazier. Just not sure yet.. Think I'll call them today and chat a bit.

 

[Joe Mc]

OK, so as mentioned the funky starting is "intermittent" as is the stalling when sitting in N and going to D or R.

Here's a video of how it started after sitting from Sunday early evening until the next Wednesday mid-afternoon, oh it was like 20 degrees and snowing lightly, just sharing conditions that's all. https://youtu.be/psiQoWi-jq8

 

[DavidC]

It almost seem's to be an electrical issue. Did you try pulling the VP plug and re-seating ?. There is also a large plug on the Drivers side, I do not know what all runs through it. I just stumbled across it when I was having fueling problems and just cycled the plug and no problems since. It doesn't cost anything to at least try.