This Problem is Eating me Inside Please Help.. Stuttering, Jerking. loss of power after 20-30 min

[supra4life]

Thank you all for the great reaponses i have gotten , i have taken all of your suggestions and concerns.. .... So far i have been driving without the fuel cap and i have not gotten any problems .. I think the fuel not venting was the issue. Im going to clean my fuel tank and look into a vented cap ... When i drive some distance the gas cap does release a lot of pressure and sometimes its hard to unscrew . I am also thinkig about buying a new coil im sure it will benefit from it..what would be the best way to solve the venting issue becasue i am convinced thats the problem.. Since my car behavea a lot better without the gas cap.

[supra4life]

Oh and 620turbo the yellow and green wire i ran to a temperature sending unit i installed a digital temp gauge in the dash

[datzenmike]

Don't replace stuff that does not need it. If it's the gas cap, changing the coil won't do anything.

[ggzilla]

The fuel filler cap should be sealed type - it does not let air out. But it does have a vacuum release valve to let air in. Perhaps it has the wrong cap.

 

Or the tank vent line might be blocked. It is under the the hood.

[620Turbo4X4]

You don't need to replace the coil. (Well not yet anyways) It needs to be wired correctly so it can work properly. The ONLY TWO WIRES that should be on the coil are orange and black from the MSD unit. Take a good look at the installation instructions and compare that to what's under your hood. I can see sitting here bored at work on my iPhone, it's not wired correctly.

 

I see orange on one side of coil (the 500+v source) going to a bunch of red wires. Looks like your 12v key on power? Hooked up like this your sending the 500v power spikes through your entire electrical system before it can reach its destination, the small ground wire on the MSD unit. Can't be good for your MSD, battery, alternator, or anything else... Hooked up properly the. 500v will be contained within its own circuit (MSD, orange and black wires, coil) and the full potential of the capacitor discharge will be available to the coil and not getting absorbed by your battery.

 

 

Where is the heavy gauge red and black wires from the MSD that connect directly to 12v battery, and ground?

 

I'm sure the tank not venting is one of the problems. (That was my first suspicion) After looking at the wiring more, I'm kinda surprised it even runs and your not having a bunch of electrical issues (gauges and anything wired to the key on switch would probably fail first). I would address this wiring issue right away and get the capacitive discharge circuit isolated like it should be, before something goes out leaving you stranded.