FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: Pentroof on January 12, 2020, 05:00:49 PM
-
Recent build, 390 with Edelbrock heads, morel roller lifters, adjustable Ford iron rockers, PI intake. Motor is in a nice 1970 f100 I built for my daughter. My initial valve setting was one full turn after zero lash.
Maybe 5-600 miles on the motor. It has run fine, but always ran a bit rich at startup. Once it started getting cold here, I noticed it started sounding real fat with a bit of a burble. I finally modified the EFI tables to lean it out a bit at cold startup. Oddly, that didn’t make much difference. It got worse as it got colder.
Finally, I decided to investigate a little more and listen closer as the motor was warming up after a dead cold start. What I hear is the distinctive sound of a valve (or two) hanging open, not a fat burble. Once the coolant temp gets above 125 or so, it starts to clear up. At temperature, the motor runs great.
So, it seems I have one or two valves that are a bit tight? Haven’t pulled the covers yet, but looking for other ideas and things to look for before I reset the valves. I thought about pulling the plugs before it gets to temp and look for a couple wet ones. If it was distinctive and only one or two, I would back off the adjuster 1/4 turn on those.
With hydraulic lifters, wouldn’t they have to be REALLY overtightened to overcome the full travel?
-
What are you running for oil? Could it be too thick and pumping up cold? Usually valves stick hot usually if dry or overheated, not cold
Morels can be a bit fussy with too thick of oil, could be your issue.
-
I’m aware, I run 10w-30 VR1. I don’t think anything is “sticking”, I believe there is too much preload on a couple valves. I think it relaxes as the head grows. I think it’s that close that a few thousands of expansion allows the valve to seat.
I’ve had this happen before on a Pontiac that my dad had set the valves on. In that case, it was an all iron motor and the valve was being held open AFTER it warmed up (pushrod growth) I was able to determine which cylinder it was simply by running it with the valve cover off on that side and loosening the rockers as it was running.
-
every fe i have had is or was cold natured.if you rev them any at all before warm up period they make all kinds of noises.i sold a 390 fairlane one time in the middle of winter.when the guy picked it up he just cranked it and took off down the road and stomped the gas pedal and it backfired and made some horrible noises.he turned around and came back and said,whats wrong with this thing.i said let it warm up,you cant run it that hard cold.he let it warm up then he called me on his way home with it and bragged on how well it ran after it warmed up.you may have something wrong with your 390,but they are cold natured,especially in the winter
-
There's about .100-.125" of travel in a traditional, standard travel, hydraulic roller lifter. I've seen some guys struggle with getting the pushrod lengths correct on short-travel lifters with non-adjustable rockers, but unless you really messed up on pushrod length measurement, I don't see it hanging a valve open when it's cold.
-
There's about .100-.125" of travel in a traditional, standard travel, hydraulic roller lifter. I've seen some guys struggle with getting the pushrod lengths correct on short-travel lifters with non-adjustable rockers, but unless you really messed up on pushrod length measurement, I don't see it hanging a valve open when it's cold.
I know, that’s what I don’t get...and I have adjustable rockers! There should be no way that I got that much preload. It absolutely sounds like it though.
Listened to it again this morning and put my hand up to the exhaust. Sure enough, nice strong puff associated with the stumble. Once the temp is beyond 135, it purrs like a kitten...clean and smooth.
I was just looking for input on what I could be missing before I pull the covers.
-
Could just be cold natured. If the valves were hanging WAY open, it would be hard to start.
-
There's about .100-.125" of travel in a traditional, standard travel, hydraulic roller lifter. I've seen some guys struggle with getting the pushrod lengths correct on short-travel lifters with non-adjustable rockers, but unless you really messed up on pushrod length measurement, I don't see it hanging a valve open when it's cold.
I know, that’s what I don’t get...and I have adjustable rockers! There should be no way that I got that much preload. It absolutely sounds like it though.
Listened to it again this morning and put my hand up to the exhaust. Sure enough, nice strong puff associated with the stumble. Once the temp is beyond 135, it purrs like a kitten...clean and smooth.
I was just looking for input on what I could be missing before I pull the covers.
Any chance it's something silly like a marginal plug wire, cracked plug, cap with an issue when cold or damp?
If it is hanging up, do a cold compression, or even better, leakdown test, it'll show immediately
-
I have a medium sized Howards hydro roller in the Falcon's 351C running Howards lifters. It's more a race car that what you're talking but it still is "off" until it gets near the 180 operating temp. Off like almost one or two dead or partially dead cylinders. After it's fully warm and ready for battle, runs good. But cold, it's just...grumpy. 10w30 oil, lifters the standard 1/2 turn down from zero lash.
-
If you went 1 full turn down on the adjustment why dont you back them off a quarter turn. 3/4 turn should be plenty.
-
Are you sure you're not getting icing on or in the carb? Not an uncommon problem on older engines that have had the heat risers and hot air plenums taken off or blocked, and it leads to a bad idle and poor performance. I used to have to start my old 390 and let it run for about 5 minutes, then shut it off for about 10 while some heat soaked into the carb and got rid of ice formation, then it would run fine.
-
If you went 1 full turn down on the adjustment why dont you back them off a quarter turn. 3/4 turn should be plenty.
I hear you. .050” should have put them in the middle of the plunger travel, but I obviously F’d up at least one. And it runs so well once at temp, I’m convincing myself I either stopped for a beer and added another turn to one or just got way off on determining zero before adding a turn. Not like me to miss the basic stuff, but I’ve had my moments.
I have a laser temp gun arriving tomorrow to determine if it’s just one cylinder and then I’ll back that one off. Otherwise, I think I’ll just start completely over and reset them all. At this point, I’ve spent more time talking about it than getting off my ass and doing something.
I’ll report back what I find. Thanks to all for the comments.
-
Are you sure you're not getting icing on or in the carb?.....
No carb on this one! ;)
-
Maybe you should start from scratch, it might be something that needs to be checked regardless if your not sure. But if you want to play around with your temp gun thats fine. Depending on how long the job is and how hot it is the beers add up. ;). Been there.
-
No carb on this one! ;)
The throttle body blades can still ice. When you're running possibilities, you don't rule out anything until you see it for yourself. In that regard, run the engine as CJShaker pointed out. If it makes no difference, then you can rule it out.
-
Are you sure you're not getting icing on or in the carb?.....
No carb on this one! ;)
I suppose that would make a difference in carb icing..lol
-
This morning I checked the temperature of the header pipes just after starting the motor.
Cylinders 3,4,7,8 are running cold at initial start. After warming for 2 minutes, all fine.
For the record, it’s a dual plane.
I’ll report once I get the covers off, but it looks like I’ll be re-setting all of them.
I find it strange that I’m not getting any popping through the carb, if it was a procedural thing.
-
I think my t-stat is stuck open.my 428 dont start warming up for at least 15-20 minutes.if i take right off after 1 or 2 minutes of warmup it sounds awful for a mile or two,super cold natured.but when the temp gets up to 150 and above,it gets crisp and peppy and ready for anything till i shut her down
-
I think my t-stat is stuck open.my 428 dont start warming up for at least 15-20 minutes.if i take right off after 1 or 2 minutes of warmup it sounds awful for a mile or two,super cold natured.but when the temp gets up to 150 and above,it gets crisp and peppy and ready for anything till i shut her down
That is generally a cold start issue related to fuel delivery. In my case, I’m running EFI and I’m confident in the tune. There is no question that I have exhaust valves that aren’t closing completely when cold. I’ll get into it this weekend.
-
I think my t-stat is stuck open.my 428 dont start warming up for at least 15-20 minutes.if i take right off after 1 or 2 minutes of warmup it sounds awful for a mile or two,super cold natured.but when the temp gets up to 150 and above,it gets crisp and peppy and ready for anything till i shut her down
That is generally a cold start issue related to fuel delivery. In my case, I’m running EFI and I’m confident in the tune. There is no question that I have exhaust valves that aren’t closing completely when cold. I’ll get into it this weekend.
Do you have the tools to do a cold leak down test? Even if no gauge, just air may let you listen to a pipe
-
Yes, I have a set of leak-down gauges. Not a bad idea to confirm before I just start resetting the lash.
-
Just a thought but valves should be adjusted properly before a leak down test no?
-
Just a thought but valves should be adjusted properly before a leak down test no?
The idea is to verify that it is indeed a compression problem. If it is a tight valve, you'll have big leak down numbers and noise out of the intake or exhaust depending on which valve is tight
-
Compression is good...which is another lesson to me that assuming isn’t the same as verifying.
Spark is good.
Rear cylinders still not firing when cold. Temp gun confirms, directly at each header pipe at the flange.
Started and shut down before the rear cylinders started firing (which they do, once things start warming up). Pulled the plugs and rear cylinders are dry and very light, as compared to the front cylinders.
So, my new theory is this Police Interceptor intake is not playing nice with the Holley Sniper. Sniper is only delivering fuel to the front bores at idle.
No vacuum leaks that I can tell, but my next move will be to pull and plug the brake booster...that’s at the rear center of the throttle body. I’ve got no other indicators that the booster is an issue, but I’m done assuming.
Anyone else experience this scenario with the PI, or any other dual plane?
-
Certainly sounds like an EFI issue.
I have never liked the electronic carb type efi.
I prefer individual injectors for each cylinder.
I am sure you will figure this out. Have you sent a message to Holley?
-
Just for giggles, throw plugs that are a couple heat ranges hotter in those non-firing cylinders.
-
Certainly sounds like an EFI issue.
I have never liked the electronic carb type efi.
I prefer individual injectors for each cylinder.
I am sure you will figure this out. Have you sent a message to Holley?
I’m a member on their forums...I posted over there, yes. I’m concerned that the progressive linkage and programming I have added may be the issue (even though offered by Holley). The rear two injectors do not flow during idle...at all.
I’m also using a a 4 hole carb insulator that could be contributing, as opposed to an open spacer. I don’t know.
-
Do you know someone with a 735 Holley carb you could throw on?
-
Wow efi and a dual plane....where have I heard questions about that?
Mixture distribution is a thing even with efi, if you have the clearance above the intake put a 1 inch or maybe more OPEN spacer on it and give it a try before you drive yourself nuts retuning.
Signal to the map sensor sometimes suffers with dual planes.
You may have the lifters tight too. Back the adjusters off 1/4 as suggested.
I’ve never had luck with the spin push rod till it drags adjustment method , I adjust till there is no up and down lash,or slack,then add 1/2 -1/4.
I’m running Brents non adjustable rollers so all my push rods are measured length plus .050.
-
Do you know someone with a 735 Holley carb you could throw on?
I have a 600 Holley from my GT motor, but I’m not going there. I know what you’re thinking, but the fuel supply would have to be rigged and I have the EFI controlling my timing.
-
If you went 1 full turn down on the adjustment why dont you back them off a quarter turn. 3/4 turn should be plenty.
I hear you. .050” should have put them in the middle of the plunger travel, but I obviously F’d up at least one. And it runs so well once at temp, I’m convincing myself I either stopped for a beer and added another turn to one or just got way off on determining zero before adding a turn. Not like me to miss the basic stuff, but I’ve had my moments.
I have a laser temp gun arriving tomorrow to determine if it’s just one cylinder and then I’ll back that one off. Otherwise, I think I’ll just start completely over and reset them all. At this point, I’ve spent more time talking about it than getting off my ass and doing something.
I’ll report back what I find. Thanks to all for the comments.
Good idea. Find the cold exhaust port. Can you hook up a laptop or scanner into it and see what your temperature sensor values are when cold? If it has a MASS the quickest thing to look at is the air intake or ambient temperature. If it is off that usually causes full time performance issues but won't hurt to see.
-
Did you check all the wires with an ohmmeter?
I really doubt it’s a dual plane issue, if you think it is, slap a 1 inch open spacer under it and see what it does
I think vacuum leak or dead wires
-
Did you check all the wires with an ohmmeter?
I really doubt it’s a dual plane issue, if you think it is, slap a 1 inch open spacer under it and see what it does
I think vacuum leak or dead wires
Swapped wires...same issue. New plugs, cap and rotor.
I believe the issue is the progressive linkage on the Sniper. This is a change from stock to alleviate the abrupt tip-in the Sniper has because all four throttle blades roll in together. I have modified the software and added a progressive link that starts activating the rear blades at about 40% of the fronts, to act more like a 4-barrel (and keep my daughter from unexpectedly lighting up the tires). This change and link is available from Holley, but “not advised”. Well, the damn thing is way too touchy with all four barrels opening together.
Anyway, the rear barrels have no fuel being introduced at idle now. I currently have a 4 hole, 1 inch spacer that may be making it worse. The Sniper injects fuel above the blades, so it bounces off the blades, pools momentarily, and then gets sucked in.
I think I have a lot of pooling and condensing going on in the plenum at cold start. 3 minutes later and all is good.
I’m going to try an open 1” spacer instead of the 4 hole. The problem is, the Sniper is known to have an annoying whistle related to the IAC in this configuration. If the cold fuel distribution is better but I get the whistle, I’ll add a 1/8” steel 4 hole plate between the spacer and the throttle body.
-
Jim I have FAST ez efi .
Back in ‘14 I installed it . It had some oddness to the throttle tip in. The tech guys are,mostly,thinking electrical or setup problems . After almost 2 years I went on Power Tour,I marched right up to the FAST trailer and said hey this thing hates low throttle tip in from a start,it bucks jerks hates life. He asked did you adjust the blades so they move together ? No. Do that and set the IAC just out of the green. Green gives IAC counts between 15-20 if I recall correctly. He suggested 25-30. This closes the throttle blades more and uses more air from the IAC. I did all the above the next morning just as the temp came up but before the fans came on,lowest load possible . Seat of the pants 90% better . The next 8% came from ditching the four hole for an open. I admit I still have a tiny hick up,but it could be the driver forgetting how to modulate the clutch.
I think setting the linkage up to slow the throttle and running all for barrels 1:1 with the blades “more” closed for higher IAC at idle would help.
I have not flipped the Holley TBI over but I think the MAP sensor only reads 1 pair of throttle bores. If so a four hole spacer of any kind would effect performance.
-
I guess all idling issues are not solved with these electronic carbs.
Electronic or old school carbs seem to require some tuning.
Anyhow - fiddling with cars is half of the fun :)
Cheers
-
I think setting the linkage up to slow the throttle and running all for barrels 1:1 with the blades “more” closed for higher IAC at idle would help.
I have not flipped the Holley TBI over but I think the MAP sensor only reads 1 pair of throttle bores. If so a four hole spacer of any kind would effect performance.
The Holley IAC procedure is a bit different, but I have it dialed nicely and I’ve never had any issues like you describe. My comment on tip-in was more about how much power came on quickly because of all four barrels at 1:1 and a linear , short throw. Lots of guys are adding an extension to the throttle arm, but that fix results in longer pedal movement. That means either an awkward pedal start location or not accessing full throttle.
-
I guess all idling issues are not solved with these electronic carbs.
Electronic or old school carbs seem to require some tuning.
Anyhow - fiddling with cars is half of the fun :)
Cheers
I would not consider my situation normal and measure all Sniper installations by this. I could have left the direct linkage alone and it would be fine if this were a hot rod. My problem is this is a 390 in a daily driver F100 I built for my daughter.
The reality is, after it’s warmed up for 3 minutes or so, everything is perfect. In warmer months, it’s a non-issue. My problem is, I want it perfect all the time.
-
Swapped the 4-hole for an open spacer and all is well.
Dead steady AFR gauge from the start and all 8 header tubes equally heating, instantly.
-
Good job!
-
Interesting thread, glad you shared it.
-
Way back when I was first fooling with Holley EFI, there was a guy who made a cam/cable link that moved the throttle slower in the first part of it's travel. It was a sure cure for 'touchy' throttle foot. Worked a charm. I used one on Brother Lon's dual Holley TBI application on his 427 '67 Mustang.
KS