76 spider heat stroke

Hi,
Here in sunny Arizona the three digit days have arrived. Daily temps are a 100F or better. My spider is hating it. After a few miles of driving, 10 or so, it will start to drop cylinders. I will find a patch of shade and sit for awhile, hood up, and this will get me another couple of miles. I do notice that just before the bucking starts, I can smell fuel, as if the pump is pumping but the plugs aren't firing it off. Power drops to what I feel is about one cylinder's worth. I've been through the cooling system just recently, things are in good order. It's not overheating in that respect. I'm suspecting coil. Is it dying from heat? Or is there another temp involved circuit cut out that I haven't read about? When the weather's cool, this thing runs like a charm. Any ideas from those smarter than me?

Is the fueltank outlet at the lower right of the tank or does it come out the top? If lower right, I'd check the main fuelpump. If it comes out the top, has the tank been retrofitted with an intank fuelpump? If it has, check the intank pump. If not, install one.

Thanks for the reply papjam. I remember you. The outlet is lower right. I had previously checked the pump and filter back there, they seem fine. But, after a second thought, could they be too close too the rear muffler causing too much heat? There isn't any heat shielding and the shielded line comes within about 2" to the muffler. Also, there is a small auxillary plastic tank in the trunk, what appears to be an expansion/overflow unit. Occaisionally I'll get a "whiff" of gas from there. But the primary fuel smell before "sputtering" is coming from the front end of things as I catch it in the face when driving. Any more thoughts? I appreciate your time. I'm just dreading the thought of something major. I like this car and would love to use it as often as possible.

You can't go wrong with papajam's advice

No, probably can't. But IAP wants $600 for a new one. I'd like to understand the problem a little more before I part with that kind of money. I don't have a healthy budget for this car so I'm trying to learn as much as I can. Do any of you know of any other outlets for parts or any suitable alternatives?

Does the low fuel pressure warning light on the dash function as it should? ie comes on for about a second when the key is first turned on? If not, the light needs to be fixed first (otherwise, everything else is just guesswork). If the light does function properly, does it light up when the engine starts to drop cylinders?

No sir, the warning light, as well as a host of other electrical devices are suspect, probably aren't functioning properly. I say that because there seems to be some interference between devices at random times. A lot of hands have been layed on this before me. Probably a ground short or frayed wiring in there somewhere. For instance, the oil pressure guage drops when I put the tranny into reverse. I haven't spent a lot of time on the wiring yet, except to get it safe and roadworthy so that I could "shake it out." There is much to do there. I haven't seen a consistant pattern between the fuel pressure light and performance. The fuel pump that you first mentioned has been a concern since I've started reviving this car. I recently tested it, hot and cold, and got little difference in it's performance. A subjective test, but somewhat indicative. Then I noticed the compression differences and finally, a slight coolant seepage around the head bolt between #2 & #3 cyl. Apparently the stud had been weakened somehow because as I put a socket on it, it came off (very little torque applied just to check snug.) My thought now is that I have to replace the head gassket, and studs, to eliminate that part of the equation before I can move on to the fuel system and electrics. I'm being intentionally wordy here because I know you're very knowledgeable in these things, you've helped me in the past. I certainly appreciate any thoughts you may come up and hope I'm not being a pest to the site because of my rookie experience. I'm pretty good with a wrench, but smart enough to know when I don't know. Thanks for any insights.
Tom

I have the exact same problem with my 78 spider - gas smell and all. It seems to be a particular issue when driving for a few miles at high speeds (such as on the highway) opposed to downtown driving. I also noticed that just prior to the sputtering, the engine will idle much higher than normal - in the 3000 range compared to the normal 800 to 1000 range. I suspect the engine is flooding, as letting it sit for a while will tend to cure the problem.

Any further insight to this relatively old thread woud be greatly appreciated.

Hi Guys,

On a very very humble side i d like to try to contribute.

A/ the coil is a part that wear off, so changing it before it fail is normal. If it's too hot it does not function properly.
B/ ignition contact point it also wear off and make a lot of different on the spark, plus new spark (if think there is a type called "cold"), even the cable connecting to the spark need to be change sometime.
C/ petrol smell, well I have this problem now coupled with a nose dive situation. My carbs are well tune but I suspect the jets are tired. when the carbs doesn't get the mix it does spit back some petrol into the air intake which result to strong petrol smell into the car. A repair kit is on stand by for when I have time to do it.
D/ heat sheild, petrol vaporized when too hot, which change all the parameter of the combustion.
E/ cooling system, how old is your water pump?
F/ new head gasket, go ahead change it, it can only help.


I have no answer, just some personal deduction from experience. I leave in SIngapore where the temperature can quite hot.

Cheers

Andre