Hi Bob
I've tried 4 sets of plugs
2 used 2 new
plugs
Hi Bob
I've tried 4 sets of plugs
2 used 2 new
Maybe you can get your engine builder to run it on his dyno. If it still has the problem, it is in the parts you sent him. If not you can ignore the engine and concentrate on the support systems.
Out of Options?
While, by far, not my first choice, it appears you've tried just about everything else . . .
Try checking the intake manifold for an air leak? Spray starter fluid all around carb/intake and intake/head joints and see if the engine rpm changes.
missing
Marvin-
That's an option - not the cheapest, but an option. Figuring freight round trip at $500. Reluctant to do that as the engine is just a few hours from fresh.
Cheaper to talk my pal into letting me swap engines one weekend. Maybe a case of Corona will do the trick!
Michael-
Tried it, no leak.
Remember this car now has a new head gasket, new intake gasket, new exhaust gasket from the head refresh.
I'm frankly torn between wanting it to be something simple and wanting it to be something really obscure. Less embarrassing that way! I expect I'll find it over the winter.
John
Suggestion on the engine miss. It is happening at high revs and you've replaced everything but the steering wheel it seems, including the fuel lines. If there is a tiny air leak inside the fuel tank pickup the fuel pump will not pull enough fuel to feed the engine but it will work fine at relatively low revs. It might even work sometimes because of fuel level in the tank covering the tiny opening.
Simple to check this. Run the engine to get fuel into the float bowl. Disconnect the fuel line at the carburetor and put the end of the fuel line into the bottom of a glass jar and start the engine. The engine will run off the fuel in the carburetor but if you see tiny air bubbles in the glass jar you are getting air into the system somewhere. At high revs the engine will 'starve' for fuel as the pump will be happier pulling air under high fuel demand. It will only happen at high revs and work fine at low revs. Good luck with this!
Line leak
I don't think that's it. I've run the car using a 5 gallon jug of fuel instead of the fuel cell. Same symptoms.
Thanks for the idea.
John
What kind of fuel pump do you use (I know you have tried more than one)? Electrics don't necessarily "lift" well on the suction side and if mounted high in the car or having to "lift" out of a jug that MIGHT be an issue. The typical Kent 1600 mechanical pump lifts pretty well. Don't know about the Pinto pumps.Originally Posted by JHerscher
Have you logged fuel pressure? I don't recall seeing that in your comprehensive list of things you've tried at least once.
Dick
Former Kent FF 1600 owner
Dumb Question: Fuel Filter??
Steve, My post #7
CREW for Jeff 89 Reynard or Flag & Comm.
As I said here, if it were me, I'd be looking only for mechanical and electrical issues. IMO, having the same behavior at high load and low load (high and low fuel /air flow) almost totally eliminates fuel and air-flow-related issues.
Dave Weitzenhof
I'd back up at this point and focus on this area again. I have NO CLUE where to look first but it sure sounds like something in that area is acting like a Rev Limiter. It's not because of all you've replaced but Ivey's Rev limiting rotor acts just like that but at 7,300 RPM.
CREW for Jeff 89 Reynard or Flag & Comm.
That reminds me about something I experienced way back when:
On some distributors, one can rotate the rotor and cap such that the cap internal lugs do not line up properly (too long a gap to properly transfer the spark) with the rotor when the spark is generated. Timing can still be correct, but the cap alignment is off with respect to the rotor due to (maybe - I don't remember what I had screwed up that caused this) the distributor rotor being off by one (or more) teeth in the drive gear. As long as the spark can jump to the correct lug, everything is fine. If it can't jump, or jumps to the wrong lug, all sorts of missing/cross-firing can occur. Having the HT wires in the wrong cap hole can also do something similar to this.
That gives varying results depending on how far off the cap lug and rotor tip are from each other when the spark is generated. The higher the rpm, the worse it would be, and humidity/temperature/ionization inside the cap could affect the results, maybe fitting the symptom of working one session, and not the next.
Bottom line: make sure they are aligned.
Last edited by DaveW; 10.14.14 at 2:00 PM. Reason: keep adding clarifiers
Dave Weitzenhof
Okay Dave, that sounds exciting!
But he said he has changed the distributor. Thinking along the same lines though, what about a worn distributor drive gear on the cam??
CREW for Jeff 89 Reynard or Flag & Comm.
Maybe he did the same thing setting up the 2nd distributor on the engine that was in the 1st one that caused the issue?
I'm not sure about the effect of a worn timing gear, but if the timing wandered a lot maybe that would cause similar symptoms.
Dave Weitzenhof
Even with this information from an earlier post?
Car would not run at all well at the track - far worse under load. It took forever to get the car to 6800 on track; in the shop it gets there pretty quickly but has that ba-da-ba-da thing going on while it gets there.
Yes. The same missing and ba-da-ba-... performance is present under low load and high load. If it were fuel or air related, it would not have the same character. The fact that it takes much longer on the track under load is just a result of attempting to accelerate and fight wind resistance of the whole car vs accelerating only the engine with no wind resistance.
Dave Weitzenhof
weird one, plate u are mounting the points too in the distributor is arcing over at the higher revs although I suppose I may have missed that u borrowed someone elses ....... hotter coil causing arcing in new wiring, get a wimpy $25 coil from auto store, probably tried that as well and u said u ran a direct wire, hotter coil, r u missing ballast resistor, fried points in a couple seconds running a straight NHRA type monster Mallory, after adding ballast was ok then, ......... sorry if this doesn't help and u tried the above....good luck
Sounds to me like timing. Check to be sure that the mechanical advance mechanism in the distributor is free to move and that the spring(s) and weight(s) are in place and free to move. If the mechanism is not allowing free advance to a total timing of something like 36 to 40 degrees (confirm total timing spec, but those are typical numbers for an old engine design), the engine will be a pig on top. A sticky distributor mechanism could also account for the time when it "fixed itself".
Pete L
Post #1 in part:
"What I've done with absolutely no effect:
New points/condenser
Exchanged distributor <---------
New Coil
New distributor cap, rotor, coil & spark plug wires
New Plugs
New Master switch
New Ignition switch
Bypassed all onboard ignition/starter wiring & replaced with mini harness made up for test purposes
Replaced Battery
Verified carb is correct - it went back to the engine builder who ran it on an engine on his dyno. Not the carb
Exchanged carb
Replaced fuel pump
Verified valve lash
Bypassed the Mychron dash - left it completely out of the system
Ran it on the onboard battery & the jumper battery separately
Replaced starter (really getting obscure here - possibly the big lug on the solenoid was arcing internally - it wasn't)
Replaced fuel lines
Verified the fuel level is correct in carb after hot cut.
Verified the fuel vent is working properly.
Fuel filter shows no signs of deterioration of cell foam"
Lawrence Hayes
Hayes Cages, LLC
Sagle, ID.
Have you considered putting the car on a chassis dyno and connecting a scope to do diagnostics?
“Racing makes heroin addiction look like a vague wish for something salty.” -Peter Egan
Pinto miss - solved (I hope)
So I sent the engine off to the engine builder and he found on the dyno that the car would cut out at 6500 like it was using a Bosch rev limiting rotor set for 6500. He swapped the various bits on and off and found that what cured it was an electric fuel pump. Apparently my 3-race-old pump and the known good pump were just that much at the bottom end of tolerance to cause the car to run out of fuel at high revs.
So, I'm inclined to make the change to an electric pump and am requesting advice.
To refresh memories - the car is a VD RF01. This has the fuel pickup at the top of the cell, so the pump must be capable of pulling the fuel from the bottom of the cell.
I've researched and know a little about the Facet pumps - my concern here is that another racer who purchased a Facet to empty his cell between events has found that it won't pull the fuel up from the bottom of the cell. I'd rather not have to run a fuel pressure regulator, so if someone has success and would be willing to share the part numbers, I'd appreciate it.
The second question I have about the electric pump is around the possibility of the pump continuing to run while the car is stationary and the engine off (as in stuffed into a tire wall somewhere with yours truly asleep at the wheel). I have an inertia switch but it looks a little dodgy to me - I've been on enough bumpy circuits and have had enough bumpy off course excursions to make me question if it would trigger at an inopportune moment.
The third question about the electric pump is mounting. I'd be inclined to mount it where the mechanical pump lives - on a plate and using isolation mounts. I do have concerns about heat as I understand these things don't like to operate in more than about 140° F and I know its hotter than that on the side of the block.
Or.....do I just get a new mechanical pump?
Thanks
John
Some fuel injection systems, including GM & Ford use an in-tank fuel pump, placed in a stilling well in the bottom of the tank. If there is fuel to pick up, the pump will pump it because there is almost no suction lift.
Regards,
Dan
“Racing makes heroin addiction look like a vague wish for something salty.” -Peter Egan
John - I have an RF 94 and I've had electrical pumps ever since I built the car in 2002. Mounted on Isolators on a plate where the stock pump was. No inertia switch, living dangerously I guess. If I was really worried I'd use an inertia switch off a 1/2 ton truck or jeep. They take a lot of off-road pounding without actuating.
I also use my old., broken "spares" as de-fueling pumps on my pit cart. I've never swapped out a pump for an electrical failure. I've had ears break off the metal ones, and I've swapped out pumps only to find out it's some other problem.
The de-fuelling pumps are mounted on the top of my pit cart, about 40" off the ground. I feed a an-3 hose down the fill neck to the bottom of the cell and it pumps the fuel out just fine, so it ought to lift you fuel 20" or so
Recently I went to the plastic pumps because the ears don't break off.
There are a LOT of part #s for these things. I can go out in the garage and find the right one if you need the number.
I know this sounds stupid, but two years ago on my VD2000 I had a high miss that lasted two laps; then the engine quit. In the shop after a few!! hours, I found that the hose inside the fuel cell had cracked at the top fitting, I'm guessing it sucked some air for a while then broke.
No, not stupid, it's happened to me in one of my road cars.
“Racing makes heroin addiction look like a vague wish for something salty.” -Peter Egan
OK, trying to use some logic here:
If it cut out at the same RPM with load (high fuel flow) and in the shop without load (low fuel flow), it is not nominally a fuel-pump-capacity issue.
So, then the question is, what in these 2 pumps really caused it?
The one thing in a mechanical fuel pump that is definitely RPM related (float due to mass and weak spring) is the actuation-arm return spring. I'm guessing that this spring in these 2 pumps has broken or taken a set (or was too weak to start with) causing the arm to float on its cam and the pump diaphragm to not return far enough at high RPM to pump any fuel. Even a little bit of fuel flow would have meant that it would been able to run in the shop under low load.
An electrical FP is not subject to this type of issue, so that seems like a good solution.
Dave Weitzenhof
For the safety cut off Longacre sells an oil pressure activated switch that opens / closes at about 10psi. IIRC it costs about $20.
Put a T in your oil pressure gauge line, screw this switch into it and wire it in series with the hot lead to the pump. Engine stops, fuel pump stops. If you need to, can wire a momentary contact bypass switch in parallel with the oil pressure switch for starting.
That is nominally a good idea. However, I used to see sub-10 psi oil pressures all the time in the pits/paddock at low RPM's after a session. So make sure the cut-off won't cause issues in those circumstances.
Dave Weitzenhof
How true that is! Used to scare me to death seeing 5 or 8 Lbs when Jeff came off the track. But, I learned that was your normal hot Pinto.
CREW for Jeff 89 Reynard or Flag & Comm.
I actually put it on my cars because I am scared to death that the pump drive belt will come off and the engine will immediately blow sky high.
It actually did once in 20 years. That $19 switch saved the engine.
Managed to put new oil pump on without properly aligning all the pulleys and it ate the teeth right off the belt.
And I have an on / off switch to use for getting around the paddock and on the pace lap and first lap or two of the race. I am comfortable with this ( instead of a momentary contact for starting only) since it is not being used to prevent a fuel pump from pouring gas everywhere in the event of a crash.
What motivated me was seeing a S2000 right before my eyes throw the belt off, promptly grenade the engine and immediately lose control on all the oil. Fortunately there was plenty of room so at least there was no crash.
Have you checked the fuel squirter nozzles in the carb venturis?
If the spring clips that hold them tight in the channels in the venturi bore are loose, and the nozzles rattle or move around slightly, you are not getting a good seal on the fuel delivery to the nozzles.
And it will show up at higher RPM, because it happened to me. lol
Hope it helps.
Don
Reynard 83SF
Steve - once I was formed up on the pace lap when one of the cars in front of me threw either a water pump or oil pump belt right over my head. needless to say I was very heads up on the start and thru the first couple of turns! must have been from another group though, because there was no disaster - but it kept me paranoid for a while!
maybe a little late
this is just a thought as i am having the same problem but what we narrowed it down to and is so small it was easily over looked, but the air check valve to the fuel cell was stuck. when the car ran at idle no problem but as soon as we were under load a mis-fire would occur, and 4 misserable weekends and 2 rebuilds later the only thing we hadnt looked at was the fuel cell and its contents, pick up line had cracks, fuel cell had debis, and last but not least the check valve was stuck closed.
I was loosing my mind for a while but this is the only thing we never checked i hope this helps people
Peter Gregor
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