Need help w/ stumbling issue....

[Danr55]

I just got a tank in Pinal County and all of my fueling issues went away. As did the dieseling issuing that's developed. It's now un-developed. There's gotta be something funny with Maricopa County gasoline.

[azfordman]

I think I am going to install an electric fuel pump to see if that makes a difference....I know I have talked to others who have had issues with the gas down here. Of course that is going to have to wait.....pushed the car pretty hard on the Arivaca run yesterday and busted the push rod on the intake valve of cylinder #2..... Looks like several of the push rods are wearing on the guides....not sure if it is the adjustment or if the guy who put the engine together used low grade rods. Will be picking up a set of hardened push rods in the next day or so.

[Danr55]

You might also want to check the rocker arms and make sure they are the right ones for your motor. If the moment of leverage is too long or too short, you'll not only change the relationship, but the location of the push rod.

[Z-linkCobra]

Originally Posted by azfordman

I think I am going to install an electric fuel pump to see if that makes a difference....I know I have talked to others who have had issues with the gas down here. Of course that is going to have to wait.....pushed the car pretty hard on the Arivaca run yesterday and busted the push rod on the intake valve of cylinder #2..... Looks like several of the push rods are wearing on the guides....not sure if it is the adjustment or if the guy who put the engine together used low grade rods. Will be picking up a set of hardened push rods in the next day or so.

After you install those hardened push rods then youll find the other weak link in your valve train. Sometimes bending a push rod is a clear sign of something else wrong. Even with wear from the guides I would still look for another problem before you put those hardened rods in there.

just a thought.

[vettestr]

Azfordman,
sent ya a PM

[Positraktion]

Note - I changed a blue Holley fuel pump for a blue Holley fuel pump last year and suddenly started blowing fuses. Called Holley, they said the newer blue models took more amperage, I had to install a relay. Just thought I would let you know. Good Luck...Posi........

[Car Nut]

Originally Posted by Danr55

I just got a tank in Pinal County and all of my fueling issues went away. As did the dieseling issuing that's developed. It's now un-developed. There's gotta be something funny with Maricopa County gasoline.

Dan,

There is a difference between the two, with the Maricopa County fuel being blended for more oxygenization for smog control reasons. Possibly the MC fuel burns a little hotter??

Just a thought.

[azfordman]

FWIW, the builder of the engine did skimp and install low grade push rods. A couple of of local engine guys said this type of problem is normal when hardened rods are not installed. The push rod did not bend, the side wall was worn away until it snapped in half like a tooth pick. Should have a set of hardened rods by the end of the week.

Just something to keep in mind when using roller rockers on a motor. Sorry if all of my issues have annoyed some of you here....in the future I will try not to bother you so much. Mark

[Z-linkCobra]

No bother at all Mark...at least not for me. I just have seen guys make a mistake like bending or breaking a pushrod and going back with hardened rods only to find out that they didnt have enough valve clearance in the higher rpm range. Then with the hardened push rods they really tore some stuff up.

How about your fuel/stumble issue....make any headway on that yet?


Gene

[azfordman]

The car ran great on the Arivaca run.....but still did not "feel", if that makes sense, like it was performing at 100%. Once I get it up and going again I will try to find a performance shop that can perhaps tune it on a dyno. Again, with the 80's block, the 70's heads, and unknown compression ratio and cam specs, I am unable to set it up to manufacturer specs. I am sure that if the average Joe was driving the car it would be perfect, but something in my gut is telling me that she is not reaching her full potential.

[Finallygotit]

Originally Posted by azfordman

Sorry if all of my issues have annoyed some of you here....in the future I will try not to bother you so much. Mark

No issues here either Mark. Not sure if someone said you were being annoying but its places like this where we can get this kind of help. I'm glad to help whenever I can. Besides, I have seen enough garbage pass though some of these threads, not only here but on other forums as well, that this is by far more interesting and helpful IMHO. I will now turn you back over to our regularly scheduled program.

[BPWilliams]

AZFord,
Just out of curiosity what do your plugs look like? If the motor is running lean from no fuel they will be nice and white, black and you might have issues in another direction, also a cheap way to diagnose issue with carbs..

WOW can't believe the last time I logged in was last December.... time fly’s

[azfordman]

Originally Posted by BPWilliams

AZFord,
Just out of curiosity what do your plugs look like? If the motor is running lean from no fuel they will be nice and white, black and you might have issues in another direction, also a cheap way to diagnose issue with carbs..

WOW can't believe the last time I logged in was last December.... time fly’s

Another complicated piece of my puzzle..... Since the car has 70's era heads I have to use the larger (7/8 I believe...) spark plugs and there are very few options available in plug temperatures. I had installed a set of Autolite 45's, but they seemed to be too hot of a plug and contributed to pre-detonation. The car had Autolite BF-42's in it when I got it, but they were pretty well worn out. My next choice down from the 45's is an Autolite 124 which I have in the car now. Last time I checked a couple of the plugs, before the Arivaca run, they actually were off white in color...no fouling like I had expected with these cold plugs.