ok so i have a 98GSR and for some reason my car sometimes just dies when im at a red light or when i let off the gas to come to a stop. My rpms will drop to 500 or less and then the car just turns off, if i pop the clutch or pull over and turn the key the car will start right back up. i dont think my idle is set too low because sometimes i idle at 1.5k and some times 500, its not consistant!

I just replaced my alternator and spark plugs(NGK Iridiums) i also have MSD distributor, wires and blaster coil! Im getting cylinder misfire codes and cant figure out why? any ideas, please help....car stutting off while driving....not too safe!

 

It sounds more like a fuel problem.....check to see if you have fuel pressure and test each one of your injectors. Since your car is OBD2 a scanner might come very very handy.

Use what a call a "diagnostic funnel" from the basics move towards a more internal problem. Since you have replaced all of those components, start by doing a compression test or a leak down test. Also if your car is running stock compression please do your motor a favor and DO NOT USE 91 GAS!!!!!

Another thing....VERY IMPORTANT!!! Use a timming light and check your timming (obviously) lol

 

Ive done a compression test, and my compression sucks. I got 190/170/120/180 from right to left! I use 93octane! do u think my compression has to do with the cutting off while i let off the throttle?

 

Its very obvious that if your compression is out of specs you have a problem. right?? but hey don't rush it.

Did you check for fuel pressure?? did you check for spark??

I said DO NOT USE 91 GAS, because if your car is not highly modified using a greater octane gasoline causes the car to have difficulties at cold start and will kill some power even if its not noticable on the butt dyno it might also get to serious problems.

 

How do you test how much fuel presure you have. The car runs pretty good as my daily other than it cutting off like twice a day!

Could the misfire codes have anything to do with the random cutoff?
Could by MSD be causing either issue, should i go back to stock ignition?

 

MSD is a waste of money and harmable if your car is pretty much stock. if you mean trouble codes than you must have used a scanner or something similar...is that correct?? I have a fuel gauge pressure installed in my car right on top of my banjo bolt where the fuel filter is check out B&M. to check fuel pressure with a tester hook it up to the fuel deliver line on your filter and turn the ignition on, that will activate your fuel pump and will send pressurized fuel to your whole system. A good advice would be to buy a Helms manual. Trust me is a great investment.

 

The internals are stock, but i have AEM intake, Blox intake mani, DC sport headers, skunk 2 exhaust, MSD distributor/wires/&blaster coil,new NGK Iridium plugs, and i just replaced my alternator! I had my CEL read at autozone, it said misfire on all four cylinders, then when i replaced the alternator i had it read again and it was just on 3 & 4!

I dont know why my idle is inconsistant, one day its steady at 1.5k and another its 500 and the car is shakey, those days when im at a stop light i have to keep my foot on the pedal a little to keep it at around 900rpm so it wont shut off!

 

ditch the msd box. There garbage unless its a msd digital 6+ box. They are proven to give you more trouble then good. The stock ignition is good to 400+hp if you have to rate it like that. The compression is out of spec but would not cause this problem at all. I would check the TPS (throttle position sensor) maybe the IACV (idle air controle valve) as far as what gas you run, the car has a knock sensor so it would advance/ retard timing depending on what octane it is running to an extent, making less or more power (small amount). I wouldnt run to low of an octain though do to the higher compression. The manual calls for 91 so thats what i would put in it. Unless your car is tuned on a differnt octain.