Now I'm Really Stumped

Yesterday I replaced the fuel pump and the car started right up. Elementary logic would suggest that fuel delivery was the problem and the problem was solved. Moments ago I decide to take a little shakedown around the block. Engine started easily. At the end of my block I turned up a hill which required more than just a slight amount of throttle. The engine missed and stumbled badly. Testing this further, I found that any more than just a slight, and slow, application of the gas would cause this stumbling. No backfiring. I pulled back into the garage and was blipping the throttle a bit to see what no-load response was like. The engine died, started right up, and then died again and will not re-start. This is exactly what I experienced last time out that necessitated the flatbed ride. Can anyone suggest what might be happening?
Again, CB Perf 1915. Dual Webber 44 IDFs. Recent valve adjustment. Approx 2500 miles since new.

Rich....

Similar problem with a BUG turned out to be the fuel pump isolater, located between the pump and crank case...

For some reason it would grab the push rod and stop the pump, with the resulting shut down.....

The rod bore is 8mm, so I used a 5/16dia. drill to open up the bore. 9(.002" appx.) Worked fine after that....

Check fuel delivery first, then see if there is any more than a slight drag on the push rod....

Hope this helps....

Leon C.

P.S. Remove the isolater to drill it...Forgot to mention that.

check the fuel pressure from the pump, had same problem when I changed pumps, carbs won't take more the 3 to 3.5 lbs pressure.

Jerry

Hmmm... Sounds like we have pretty much the same engine, but I have an electric rotary fuel pump. The only things that spring to mind beyond what the other respondents have mentioned it to go ahead and make the move to a rotary, or to (you'll hate me for this) clean the carbs yet again. I really don't think it's the latter, tho'.

read my last post here:
https://www.speedsterowners.com/forum/readmsg.asp?t=12584

several things to look at, Check the fuel pickup, check and make sure you have gas in the tank, don't trust the gaguge. Check your carbs and make sure that fuel in flowing into the bowls. If the bowls are empty, you have either a fuel obstruction, out of gas or a bad pump.

Interestingly, electrical problems can also make you believe that you have a fuel problem. Had a customers car that would run, then die, then run etc. Originally thought it was a fuel obstruciton so I cleaned out a bunch of metal chips from the gas tank. Seemed to solve the problem for a short period of time. Ultimately, the car stalled and wouldn't start. Turns out it was a bad splice in the wire look on the wire that energizes the coil with 12 volts. Once I ran another wire, the problem never came back. Another problem I encountered was a poorly grounded Compufire module. The car backfired, ran lousy, and totally stopped. Turns out it was the not grounded properly to base of the distributor. Removed the module, used steel wool to remove the carbon arcing caused by the bad ground, then I re=assembled the compufire, put a drop of loctite on the screw and that problem was solved.

good luck

I had a fuel pump that was pumping at 9psi. I added an adjustable holley pressure gauge and it's been smoooooove sailing.

Did you try loosening the gas cap? Perhaps the vent tube/hose is stopped up and a vaccum is being formed. Easy to try.

Maybe crap in the tank that gets sucked into the tank screen , settles once it quits and fires up?

Larry is right---when you get to the "no start" phase. Stop, pop the top off a carb or gain access to you fuel bowl(maybe you are lucky and it has a bowl drain) and check for fuel. You have to eliminate or validate the fuel source. How about supplying a temporary fuel supply
to your carb when you have the no start condition?
1. if you engine will idle for extended periods ok then it's "probably" not your fuel pump
2.if your engine will start, idle normal but won't move under a load it may be fuel blockage in a main jet (but this wouldn't cause a "no start"

Good luck!!!!

Alan and Bruce, what you're saying really seems to fit my situation. I have a busy week ahead and may not be able to work on the car for a while, but I know what my next steps are. Considering the amount of crud I found in the fuel filters a while back, I suppose there is a good chance of blockage either upstream or perhaps some of the goo made it through the filters and into the carbs.
There is a screen where the fuel passes out of the tank? Is it reasonably easy to clean?

If you have grud in the carbs you have grud in the tank for sure.....Most tanks have a screen that is located in the tank , to access it you remove the fuel outlet nipple ~Alan

I've been so focused on a fuel issue that I forgot something else. The last coupla times out the tach needle has been swinging wildly while accelerating. It settles into an apparently accurate reading at steady engine speeds. This is new behavior and started shortly before this other issue. Could they be related?

I had '60 bug that almost drove me nuts. Finally, I added a new steel fuel line from the tank to the motor. Things then got well! As a matter of fact, I still have 2 extra mechanical pumps and an electric fuel pump left over from that ordeal.

Rich, Could be related to the electrical problem I posted above. If you have a point eliminator, one of the symptoms was a bouncing tach needle. Check it as described in my previous posting

Had a simular problem with a buggy once. Would run around town just fine but as soon as a long load was applied it would die. It would then not start for some time. After messing with it for a while it would start and run fine. Never sure what fixed it so I would go on my way just to be frustrated again later.

Turned out that I had loosened the clamp on the distributer at one point to adj the timing and forgot about it. When it would go to high revs for a short time or be put under load the dist. would pop up and out of the slot in the dist drive. While cranking it when messing with it, it would eventually find its spot and fall back in. Man, that one was a hard one to track down.

You guys are going to laugh at this one and at me too, but here it goes: if the tank does not vent properly, you can develop a vacuum in there that will fight the fuel pump, and eventually limit how much gas can get to the system, ultimately shutting it off. If the vent clog is not 100%, then when resting, the vacuum will leak off, and things will be right for a while. How do I know this? I have a riding mower w/ a plastic gas tank and the vent is a pretty tiny hole in the filler capn that allows air to come in, but not out. Nearly invisible, unless you know what to look for. Said cap sits on the top of the tank. If you mow when it's dry, dust/dirt can be drawn into the hole and clog it up. All the symptoms of my mower are the same as your car. One day, noticed the sides of the plastic gas tank were drawn in concave, and this released when I undid the cap to check fuel level. Cleaned this little hole, restoring the vent, and all problems were solved.

Just $0.02 worth.

Hmmm... Rich, your vent is a rubber tube that is connected to the filler neck and exits in the driver's side fender. I suppose it's possible that it's blocked. It would certainly be an easy check.

Had that on my car as well - I used a tank sealer/recoater and when I drained the tank some of it got in the vent. If you open the tank lid and there is a vaccum or sucking sound it is plugged and needs to be cleaned out.

I think he already checked this by opening his tank and didn't hear
a vacuum hiss.

Is anyone using a vented cap on their Speedster?

I have what I am told is a vented cap. I haven't finished the car yet so I don't know how it will perform.

Rich,

I just sent you a detailed e-mail, but in short, YES the two can be related. Bouncy tach is generally a sign of a problem in the ignition system. Whether it be a compufire unit going south, coil, or simply a loose wire, I'd look there.

I'd also upgrade to the rotary pump as Larry suggested. Not that you'd have a bad pump out of the box, but I've seen stranger things...

Call the shop or cell if you need any live phone support.

Carey

I have jumpy tach syndrome also. JPS is supposed to be sending another tach to swap out so we can see if its the tach. My feeling is that it is the system design, and so this effort will change nothing. Loose wire?? Where? I have the electronic distributor. Would appreciate the low-down on what's happening here. Same symptom: when you push down for accelleration the tach jumps up to a rediculous RPM right away, then settles back to what looks about OK in a few seconds. The needle is not well damped, so even when it's running "right" at a steady speed there is some bounce in the reading. The result is I don't have good clue (just what my ears tell me) the engine is doing wrt the red line when accellerating. Any advice about what to check here would be good. Start another thread?

I had an old Opel GT that had similar problems. After spending lots of $$ at the dealership (and swearing I would learn more about cars!) they sent it to an import specialist who found that the fuel pump diaphram was deteriorating ever so slowly. Each time they rebuilt/cleaned/replaced the carb they cleaned out the crud just long enough for them to test drive and me to pick up and drive a couple of clicks before the car would struggle and eventually stop.

Kelly,

I should have clarified that Rich has the Brazilian VDO tach. My experience with them is that they are generally really smooth unless there is an electrical problem...
I'd assume you have the Chinese gauges... When I tried a few sets of them I had some that would bounce, some that would stick at 3K, and some that wouldn't do a damn thing... so... I wouldn't necessarily say that your problem would be the same. Just FYI when I pitched all of the Chinese gauges they were replaced with our stock Brazilian gauges and NONE of them had a bounce, miss, nada...

Carey is absolutely right; I had the Chinese jumpy tach syndrome and after replacing the tach once (the one the car came with new from the shop wouldn't work; period) it started the jumpy routine and finally quit working. I just shipped it to North Hollywood Speedometer to get it VDO'd (they swap the innards to VDO) and haven't had a problem since.

I too had a Chink-a'nese tach that looked like a Mexican jumping bean replacded it with one of Cary'e Brazilian units and problem solved.

HEY WAIT ! ! !

Before all of you guys decide to pitch those Chinese Tachs, send 'em to me! I could really use the bezels . . .

Are thiose chrome bezels and could they replce the black ones I have on my 914 guages?

NOPE ! ! ! Those are the chromed bezels that will replace the black ones on MY 914 gauges . . .

TC I just went out to the shop and checked this ....may be a tad oversized for the 914 speedo and tank gauge ( too small for the 914 tach) I do have a dead tach with a as new chrome bezel I will be glad to donate ..send me your address and I'll shoot it out to you .

I wonder where all the dead Chinese tachs Do go ? Alan

...Mattell!

Thanks SO much for the offer, Alan! I just emailed you my shipping info.

So . . . YOUR drclock, eh ? ! ? ! ? ! Seems like I've been bidding against you all my life. Do me a favor, STAY AWAY FROM EBAY ! !

I'll be watching you from now on . . . .


Oh, anyone else have any dead gauges with chromed bezels to donate? They're going on the 356 body/VW mechanicals prototype coupe, so you KNOW that it's for a good cause, AND I'll owe you one . . . like money in the bank, I swear.

Ok TC, I deleted my eBay account because you said too :)..... tach will go out early next week !

OK, folks I just need a tiny bit more info: Like what goes on at N. Hollywood Speedo, and how much do they want? How do I get in touch w/ them? And what about the Brazillian VDOs? Do they swap out? How much coin and who sells them?

NH Speedometer contact Valdig (tech) 818-761-5136

IIRC it is about $160 to swap innards.

The Brazilian VDO gauges are the same size, but they are facelit rather than backlit, and the light green color isn't an exact match either. IN short, thay aren't an exact match for the Chinese gauges.

As for who sells them... well... I don't know of anyone (myself included) at the moment. We have to program a set number of gauges at the beginning of the year, and getting additional sets can be a real PITA. At the moment I have what we need to complete this years production and nothing more... If that changes I'll be happy to post a note (I ALWAYS have additional sets on order, they are just not being delivered). In the interim, while NH is expensive, they do quality work.

Oh yeah... sorry for the hijack Rich.

Keep me/us posted on the progress.

Here you go:

http://www.nhspeedometer.com/

They are magicians when it comes to gauges ! ! ! Get in touch, tell them what you need/want and they'll let you how much.

Have sent inquirey to NH Speedo. Carey: thanks much for the contact info, and background about the other options. When I mentioned the jumpy tach feature of my new ride, a friend of mine at work who owned a 356 roadster once upon a time observed that the new tach then operates much like to old ones did. Haha. Of course he is right, the original VDO gauges (cable driven as I recall) did have their own issues, and were not perfectly smooth either.

Carey wrote: "The Brazilian VDO gauges are the same size, but they are facelit rather than backlit"

That's true, but the Brazilian ones I have set the depth of the bulb to the faceplate (glass) differently than German VDO gauges, thereby making the "light" in the background very faint (like you had a single birthday candle lighting each gauge).

I reworked them from the following article and they are more than twice as bright than before. You can actually see the numerals and can, at times, turn down the intensity!!

http://speedstershop.com/viewtopic.php?t=4

Be aware that you must remove the gauge from the dash to do this rework, but that's relatively easy to do.

gn