Aftermarket Cam idle woes

So is that immediately after you key it off? Do you have a fuel pressure gauge? I've heard brake boosters leak as well so it could be that, might try listening by the booster.
 
That's key on engine off setting TPS to .98v with the throttle body off due to the sensor location. Every time I remove it to adjust it, you hear this hissing sound from the inside of the intake manifold. Which is why I studded and spaceredthe TB from the intake, it's a pita to get to, not for performance reasons lol
 
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jetski247 said:
That's key on engine off setting TPS to .98v with the throttle body off due to the sensor location. Every time I remove it to adjust it, you hear this hissing sound from the inside of the intake manifold. Which is why I studded and spaceredthe TB from the intake, it's a pita to get to, not for performance reasons lol
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Could the hissing you hear be an injector(s) leaking/spraying/ not closing properly/malfunctioning?
 
That sounds like vacuum leaking back into the manifold after shutdown. Pull the vacuum lines off one by one and see which one is making noise. It's odd that it lasts so long, but if it's just a leaking check valve it could take it a little bit depending on how large the reservoir is behind it. You'd have the brake booster, HVAC system, vacuum res, and EVAP system plus maybe one or two others I'm forgetting.

I guess it's also possible you could be building crankcase pressure that's bleeding out after shutdown, but I'd expect some other symptoms to go along with that. On a similar note, you would have a cylinder coming up on compression when you shut it down. The compression in that cylinder could be leaking back through a valve, but it would have to be all the valves and that seems unlikely.
 
Bobwhite, That's what it sounds like to me.

It's not vacuum, you can come back several minutes later and it's still doing it and I doubt the canister has that much vacuum. But....I may have put a vacuum line in the wrong spot. I've got the tvr hooked up that the top nipple went to the vacuum tree and bottom nipple to egr.? It's the front solenoid near the coil, I'm double checking it's routing and function and post back...... Which if I had the tvr hooked up wrong, opening or closing egr or trying to would explain the randomness of the idle issue.
 
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jetski247 said:
Bobwhite, That's what it sounds like to me.

It's not vacuum, you can come back several minutes later and it's still doing it and I doubt the canister has that much vacuum. But....I may have put a vacuum line in the wrong spot. I've got the tvr hooked up that the top nipple went to the vacuum tree and bottom nipple to egr.? It's the front solenoid near the coil, I'm double checking it's routing and function and post back...... Which if I had the tvr hooked up wrong, opening or closing egr or trying to would explain the randomness of the idle issue.
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If you were dumping raw fuel in you'd know it. not only by smell, but your oil would be full of it and plugs would be wet. I am going with vacuum as well.
 
The dumping raw fuel may explain why when I start the truck it wants to pop off before a single revolution is made, then dies or lags then goes lump lump lump until the IAC kicks in, then goes to 1800rpm like normal. But I'll start unplugging injectors One by one to see if it goes away then we'll know for sure.

As far as the tvr solenoid, I had the two lines in the wrong spots, not sure on the lightnings but this one is green vacuum line to top nipple that goes to the egr, and black main line goes to bottom nipple. So I swapped them and tested for a while when I picked the kids up off the bus and so far so good. May need to do another throttle rpm adj/reset still but it never died. Not smooth but it never had a smooth idle from the factory, it always had a shimmy and shake at idle. Rpm was probably about 650 so it may need to be bumped up.
 
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Day 2 testing, so far so good. I still have to figure out the hissing but idle issues are much better. Still has a 100rpm fluctuation every now and then but for the most part, pretty steady. I cant believe after all this time, after swapping cams 3 times, switching from maf to SD and back again.......removing this, checking that, removing it again, even checking valve lash several times......which i think I need to shim a few still. Checking torque converter to make sure it's not locked, line pressure, omg.......i can't tell you how many things ive swapped or checked trying to get rid of this wierd @$$ random idle issue of it dieing. Cuz it always died in traffic or trying to pull out in traffic.
 
If it is a leaking injector, unplugging them won't make the noise stop. I find it a little hard to believe that an injector leaking would make noise for very long. Liquid in a basically rigid line loses its pressure almost instantly if there is a leak. Even if it was hot and turning to vapor in the lines I wouldn't expect it to go for that long. When cold it definitely wouldn't. Do you have a way to look at your fuel trims? If you have a leaking injector it would show up there. You could also put a fuel pressure gauge on it and see how quickly it bleeds off after shutdown.
 
Well, armed and ready, the noise is gone. While wiring in a pigtail to make setting tps easier instead of backprobing, its zero noise now....... what else would make a hissing noise that long with the key on?

Oilwell, i wish I could monitor such things. I cant invest much more on the thousands I've already spent, lol.
 
You can usually pick up a Snap On MT2500 on ebay for $100-150 on ebay. Money well spent to see what's going on in there. Mine paid for itself the first time I plugged it in.
 
Do you have a fuel pressure gauge? See how long it takes for the rail to lose pressure after you key it off.
 
jetski247 said:
Thats doable. Ill research that so when I get one i know how to use it. Can you adjust anything with it?
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No. It just let's you read and clear codes, view sensor data, and run function tests. I'm not sure how it works with a MAF conversion. My driver is a 1990 F-150 and I have to tell the MT2500 it's a later model to get data, but it will read it if I tell it it's a newer truck. I would look into other options as well. I just mentioned that one because it's what I have. I got it probably 10 years ago with every connector and cartridge I needed to work on all the cars we had at the time for $100.
 
So it acts like a modern obd2 scanner for ibd1? Instead of the Morse code lol.... sad thing is I own several thousands of dollars worth of fancy Bluetooth scanner/tuning software but its for sea doo, kawasaki, yamahas, polaris, Suzuki, honda Johnson evinrude, mercury lol....
 
jetski247 said:
So it acts like a modern obd2 scanner for ibd1? Instead of the Morse code lol.... sad thing is I own several thousands of dollars worth of fancy Bluetooth scanner/tuning software but its for sea doo, kawasaki, yamahas, polaris, Suzuki, honda Johnson evinrude, mercury lol....
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Pretty much. And it also does OBD2 generic as well as vehicle specific if you get the connector and cartridges for that. It is one of the few scanners available that can read Ford OBD2 misfire data, but you have to know the secret handshake to do it. My only real complaint about it is that it doesn't work on newer cars. I think mine cuts off at 2004 or 2005, but some will go a few more years. I think the 2500 was discontinued in 2009, but can be updated as far as 2012. It's really a great tool for older vehicles.
 
I've spent a lot more on a lot less lol....ill def get one, ive been watching youtube videos on them. It would be very beneficial to watch and monitor sensor data to see how often it may go out of whack.

Oh, just got over my 3rd round of covid. This time it messed up my taste buds, they're about 50% now. Kids bring it from school I guess cuz they get it first along with my 1yr old. Ive never had the shot, infact I've never had a flu shot, but im finally considering one now that I'm in my 40s
 
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Well ye ol exact same systems popped back up. Thought I had it whipped but nope. Strange idle rpms, dieing in gear..... all over again. No new check engine lights, just 31 and 67 which is always there. Removed my a9p to see if a pin maybe came loise but all was well.

Im beginning to wonder if this maf meter is going wacko. Ive got a stocker and 19#ers im going to swap tomorrow, hopefully my original maf meter is going to work. Problem is its tiny compared to the 76mm couplers where its going. If idle issues go away for longer than a couple weeks ill know.

Ill get it to purr like s kitten, give it a couple quick revs then it hangs at 1k. Ill back idle back down, re adjust everything, give it s couple quick revs then it idles rough at 500rpm and lumps like a big cam......... i dont get it. If i try to drive it, you can hear it popping back through the intake into the airbox at around 1500rpm, then like a light switch, it will smooth out and take off.

Ill check fuel pressure but the pump wss just replaced a couple weeks ago as well as the sock and inline filter and i cleaned the tank. Maybe some trash got past and is caught on the tiny filters on the injectors? Who knows
 
If i cant get maf to work im unfortunately going to have to go back to speed density then stock cam because I cant afford to die at an intersection lol
 
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