varnerinc

hell guys i have read some posts on here and it seem like you all are very very professional and know what your talking about, hopefully you can help me.

1. i rebuilt my top end on my motor, took the heads down to the machine shop had them do the valves springs and heads, i put fel pro gaskets down torqued heads, intake manifold, upper and lower all down to spec and used the medium grade fel pro gaskets or high grade, i put in a brand new fuil pump, sending unit, filter, regulater, and injectors, i also replaced the rear main seal, oil pan gasket along with a mellings oil pump, pickup, and shaft, i also replaced the timing cover,borg warner ignition control module and crank sensor, ngk plugs, msd coil, accel cap and rotor, my worries are my msd lt1 make it yourself wires, the boots are all the same vortec/lt1/lt4 i tested everything and i get spark all the way to the boots, but no spark when i pull my plug out and ground it. im really fluttered as what it could be considering i replaced bassically about everything i took the cap of the rotor turns, i tested my coil i get enough ohms going threw that, i put the little pen that lights up when u get spark, and i tested my cap and spark plug booots and i get spark at both, i even put an ohm meter to my wires and i get 1.3 ohms i think. so im hoping theres a guru god that knows whats up and will tell me what it is please help hah!!!!!!!ill send u 20 bucks personally if you help me!

octaneman

Hi varnerinc


First, determine what type of ignition system you have, is it HEI ( High Energy Ignition) or DIS ( Direct Ignition System). Not all wires will work on certain ignition systems if you are using high performance wires, the ignition coil must match the specs on the wires to give it enough juice to go through the wire. To do this you will have to calculate the ohms/ft on the wire by getting the specs on them, then you apply ohms law. Should there be excessive resistance on the wire ohms/ft the spark will not go to the spark plug.

In your post you mention that you are using NGK spark plugs, the numbers on the plugs may match ,but NGK's are not made for GM engines. Only original AC Delco should be used and then re-do the spark plug gap, the range should be between .035 to .045.


post back your findings.

varnerinc

i believe its a hei its a 96 vortec 5.7 motor spider injection with a distributor and a hei 3 pin coil.

anyways i found my problem is that im not getting any power to my crank and also brake fuse inside my fuse panel in my dashboard.

i ripped apart the dash and i have a feeling when i wired up my harness i accidently mixed up a red and yellow wire, (that yellow wire being part of my crank sensor fuse) into my steering column harness, do you think i might of fried my computer? or wires? i have a purple wire and yellow wire coming from my computer to my crank sensor and a pink wire from my sensor to my fuse box underneath my hood, i believe it goes to ignition A, and somewere inbetween the purple wire goes to my fuse box on the side of my dashboard, the purple wire goes to one side of the fuse then a thicker yellow wire goes from the other side of the fuse and intergrates with 1 othe yellow wire and a red wire to my steering column.

any suggestions?

octaneman

IMO I don't believe you did any damage to the computer or the wires, because if you did it would have been noticeable immediately when you turn on the ignition. When doing any type of wiring always remember to keep handy a schematic diagram of the circuits your working on, this helps you to avoid making costly mistakes and the work goes allot faster and safer in the long run.

Here's a link where you can find your schematics. http://www.autozone.com/autozone/

varnerinc

thats the thing, all the wires are in the right spots, and i dont get any signal to the crank sensor fuse, and neither do i get any volts coming into the socket, so can you explain how this is possible?

octaneman

The crank sensor works like a Hall Effect device, the computer gets the signal at every 45 to 90 degrees of flywheel rotation (aprox). So even if the ignition key is on, you may not see anything on the meter or test light because the engine has to spin. What you can do is take your meter, and do a continuity test on the sensor and then on the crank fuse. Isolate each device separately when you this so you can have a clearer picture of which device maybe open or shorted. Do the same continuity test on the wires coming from the fuse box to the dash, and finally test the computer pin connectors for the crank sensor circuit. If everything turns out OK and you still don't have a signal, only then you can make a conscience decision to replace the computer.

Note: Make sure that all engine grounds to the computer and sensor are clean and tightly secured.

To test the crank sensor attach your meter leeds to the sensor pins you should have in the vicinity of 2-500 ohms (approx) check your spec sheet.
Once your done keep the leeds on the sensor and set the meter to AC volts and crank the engine, the meter should be from 0.2 to 2v A/C.


post back your findings.