78 Mustang Mach 1 Question

Hey, im new here cause i am 16 and just got myself a 1978 Mustang Mach 1. I have a question though, i drove it home just fine and everything was running great and i drove it around town a bit and it was just fine and i was very happy with it. However my dad messed with the screw that adjusts how high the car idles, and now it seems to be sputtering and like dying while im driving in like first and second gear. Now im not a mechanic, (and i know from computer forums im in and stuff because im a computer technician that just like i would on a computer forum your going to talk very mechanical ha ha) however any help like telling me if that screw is the culpret or if it was something where it just stopped working or maybe a spark plus is dead would be AWESOME. Maybe this is an easy problem, maybe its not, but if anyone had any info i would VERY much appreciate it.
 
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take it to a REAL mechanic!or you can raise the idle screw yourself a little bit at a time til it stops dying out.I just hope he didn't mess with the mixture adjustment screws,thinking they were the idle.then you will have to take it to the shop to be properly set.
 
welcome,
its hard to tell from your description whats going on. i would have dad set it back where it was and test drive again. it really depends exactly which screw he turned. if he turned the air/fuel screws its a problem. just the idle screw
wouldnt cause your problem..
is car factory stock?
engine size?
how many times have you drivin this car?
why did he turn idle up ? was it idling to low?
maintenance done at all?
mileage?
 
The car is pretty much stock, there were some things that were added some Eddlebrock something (sorry i really dont know im trying to learn this mechanical stuff.) It has a 302 v8. 74000 miles. i drove it thirty miles down freeway and everything and it ran fine, and around town too. now that mention that fuel/air adjustment i would doubt if thats what the problem is, it seems like that could make it ran very poorly. thank you both for your help, any further would be nice after i gave you the info. also is there a way to tell the idle screw from teh mix screw? the one that he turned was attatched right to the throttle thingy in there, which would make it seem to be the idle screw. he LOWERED the idle because it was idling very high, not the other way around. thanks again.
 
Heheh sounds like a sweet car you own. My first car was my 2+2 that my grandfather drove up from Oklahoma. Can we see pics of your car? My next II sounds exactly what you have. A nice low milage Mach 1! :nice:
I had the same problem with my car for a while there. It would stall and idle roughly esspecially in cold weather. The engine had been rebuilt prior to that. Somehow they messed up the idle mixture and the vaccum lines. It was a confusing mess of a problem that took a while to fix. :shrug:
 
Sure ill get some pics, and by the way its a manual of course!! :D The problem is fixed now though, we have to thing idling a lot lower, before it was at about 4000 RPM!!! Now down to about 1500 alot better, and we also worked on the choke and it is running GREAT. Its got major power. How should i get you the pics?
Thanks
Dave
 
daveozzie999 said:
Sure ill get some pics, and by the way its a manual of course!! :D The problem is fixed now though, we have to thing idling a lot lower, before it was at about 4000 RPM!!! Now down to about 1500 alot better, and we also worked on the choke and it is running GREAT. Its got major power. How should i get you the pics?
Thanks
Dave

4000RPM :eek: were you drivin around like that?? carb problems??
o.k. im assuming the choke wasnt set right either. 1500RPM is just a little high.
you should be at 800-900RPM when the car is fully warmed.. :D
 
Yes we have it down idling to about 500 i want to bring that back up to about 900-1000 cause thats a little low and it dies sometimes when i start it that low. Yes the choke was also the culprit. It is know running AWESOME! We fixed the choke and the idle screw to good settings (except that im going to tighten that screw a bit more to make a little higher) and it is running grand! Thanks everyone for the help. I will post some pics or link to some once i get a new digital camera. Thanks for the help everyone.
 
However there is something else i have a question about since you guys all know so much about cars. My fuel guage doesnt work, but the alternator and temp guage work. All the wires are plugged into the back of the control panel as for as i could tell when i took it apart. Would this be something wrong with the actual sensor then, or something else? Should i jsut bring it to a mechanic to get the fixed? Thanks.
 
daveozzie999 said:
However there is something else i have a question about since you guys all know so much about cars. My fuel guage doesnt work, but the alternator and temp guage work. All the wires are plugged into the back of the control panel as for as i could tell when i took it apart. Would this be something wrong with the actual sensor then, or something else? Should i jsut bring it to a mechanic to get the fixed? Thanks.
:jaw: I have never seen an alt guage that works

is your needle dead or pegged?
 
Ha ha, it the alt guage just BARELY moves when i start it ha ha. But anyway, the fuel needle is just sitting all the way at empty like when the car is powered off, and when i start it up the temp guage goes to place the fuel just sits there doesnt even jerk or anything.
 
Wart said:
They all work, you just need a magnifying glass to see it.

If you increase the resistance of the shunt, you increase the sensitivity of the gauge. Making the shunt wire longer and/or smaller will help - but overkill burns up the gauge and maybe even the car.

If you decrease the resistance of the gauge itself, you also increase the sensitivity. On the other hand, increasing the resistance of the gauge itself makes it less sensitive. I suspect contact corrosion is the real culprit in why these alt gauges barely move.

The alt gauge is in parallel with a short shunt wire. Most of the current passes through the shunt. The amount passing through the gauge is related to the ratio of the resistance of the gauge to the resistance of the shunt. Over time corrosion at the contacts between the printed circuit and the plug, as well as between the printed circuit and the gauge, increase the resistance through the gauge, making the path through the shunt even more attractive for those lazy lectrons.

An intense cleaning of all contact surfaces in the gauge path would most likely help to some extent.

Sorry for rambling again.
 
Johan said:
If you increase the resistance of the shunt, you increase the sensitivity of the gauge.
If you decrease the resistance of the gauge itself, you also increase the sensitivity. On the other hand, increasing the resistance of the gauge itself makes it less sensitive. wow you sound like me teaching my electronics class a few years ago


The alt gauge is in parallel with a short shunt wire.
Most of the current passes through the shunt. but none if the starter current goes through the guage due to the solenoid
The amount passing through the gauge is related to the ratio of the resistance of the gauge to the resistance of the shunt. Over time corrosion at the contacts between the printed circuit and the plug, as well as between the printed circuit and the gauge, increase the resistance through the gauge, making the path through the shunt even more attractive for those lazy lectrons.

An intense cleaning of all contact surfaces in the gauge path would most likely help to some extent.

Sorry for rambling again.

why not get a better guage and route all current minus starter current through the guage bypassing the shunt
 
Sorry your getting cought in the middle on this one.

I've written on this subject 3 or 4 times in the last year. So have others. I have graphics and hard numbers on the sending unit but since people like to complain about Me I'm keeping it to myself, this time.

I'll let the little wankers answer your question.

Sorry your in the middle. Thank the respectable people for putting you there.
 
Wart said:
Sorry your getting cought in the middle on this one.
I've written on this subject 3 or 4 times in the last year. So have others. I have graphics and hard numbers on the sending unit but since people like to complain about Me I'm keeping it to myself, this time.
I'll let the little wankers answer your question.
Sorry your in the middle. Thank the respectable people for putting you there.

Now that's the old Wart we've come to know.:worship:
 
Wart said:
I'll let the little wankers answer your question.

Wanker? Hey watch it, I resemble that remark. ;-) Wart you are the proverbial floating snickers bar in the punch bowl of life. Never a dull moment passes when you're at the helm.

Anyhow I don't know the answer to daveozzie999s question. However hopefully one of my fellow wankers will come in from out of the rain and spout off some statistics on the electrical resistance of the fuel sending unit degraded over time. Where is superman ..er, I mean Cobraman when you need him? :)

d