poor horse runs like ****! :(

[lordhell]

ok guys heres the story, i had msd ignition installed, and the car started giving me problems until it wont even start, i took it to a shop and they took off the msd ignition and changed the msd coil packs to stock coil packs. i pick up the car and the car is running like ****, at 1500rpm it shaked like a... unbelivable, when i check the sparks in the coilpacks 2 cylinders are not even firing, so i change spark plugs and change back to the msd coil packs the all 8 cylinders fire now but the car still runs very bad, sound nasty and i scense a strong fuel smell every time i drive it, today i popped up the hood and took a look, i check the connectors that go to the injectors and the car reacts on 6 of them (meaning the shaking increases, but 2 of them I can connect and disconnect and the cars idle wont change at all. Is this an electricity problem? or an injector problem, because have in mind that its 2 of them failing.

 

[forpit2000gt]

what year and what engine?

 

[lordhell]

96, 4.6

 

[forpit2000gt]

plug wires could be bad, how did you check the firing of the coils? The fuel smell is coming from raw fuel that isn't being burned, so I would guess that the injectors are working and dumping fuel into the cylinders that aren't firing. Pull the plugs out one at a time and see which ones are wet or really black, these are the ones you need to check out and see why there is no fire. Are you sure all plu wires are in the correct location and pushed down all the way on the plugs?

 

[lordhell]

plug wires could be bad, how did you check the firing of the coils? The fuel smell is coming from raw fuel that isn't being burned, so I would guess that the injectors are working and dumping fuel into the cylinders that aren't firing. Pull the plugs out one at a time and see which ones are wet or really black, these are the ones you need to check out and see why there is no fire. Are you sure all plu wires are in the correct location and pushed down all the way on the plugs?

plug wires are msd 8.5mm 2 month old, i thought they might be bad and i replaced them for stock 8mm wires, no change at all so i figured the msd were good. I checked the firing on the coils by unpluging one by one and looking at the spark produced between the coils and the coil packs, The 2 injectors on which I frist explained that the car did not have any reaction in, have the new spark plugs all black like you said, only those 2. What are the reasons of not getting fire if i do see the spark when I unplug the coil from the coil pack? ---- the plug wires in fact are in the correct location and all the way down.

 

[forpit2000gt]

I believe the next thing before the coils is the EEC( Computer) The crank sensor tells the computer where to start, if it were bad you shouldn't get any spark or all would be misfiring. Have you disconnectet the battery and reset computer? Is there a chip installed? if so disconnect battery and unplug chip. Do you know someone with another 96 to swap computers with? When I go by my friends shop today, I can find out a little more. I have worked on a few of these but am more familiar with COP(99 ups) .

 

[lordhell]

I believe the next thing before the coils is the EEC( Computer) The crank sensor tells the computer where to start, if it were bad you shouldn't get any spark or all would be misfiring. Have you disconnectet the battery and reset computer? Is there a chip installed? if so disconnect battery and unplug chip. Do you know someone with another 96 to swap computers with? When I go by my friends shop today, I can find out a little more. I have worked on a few of these but am more familiar with COP(99 ups) .

dont have friends with mustangs I do have a diablo chip and Ill try disconnecting the battery and the chip tonite, please keep me posted if you think about anything else.

 

[forpit2000gt]

I worked on one once that I could put pressure on the chip and the car would run great, release and it went to crap. The connectors may need cleaning but see if you can get it to fire correctly without the chip first.

 

[lordhell]

So is the suggestion only disconnect the battery? anybody else know what could the problem be?

 

[lordhell]

guys, checked compression today in the 2 cylinders... 10psi... most likely blended valve, whats the next step? P.I head swap? just get a used 2000 and on engine?