Why wont it start! Options

[cajon]

So I did an engine swap. Bad 7afe for a good 7afe. The long and short is, the engine is in. Bolted up, wired up, and wont start. Ive have good grounds, I'm getting power to the relays, fans, etc. But the starter isn't doing anything. I know its hooked up, because i never disconnected it during the swap, and I never had problems with it before. WHAT IS GOING ON ?! .......HELP!

[Box]

Ground to starter perhaps? Ignition switch. If it's an automatic, could be a neutral safety switch acting up. Would be something along those lines if the starter isn't even bumping over. Odds are it's something simple. I forgot to attach the ground to a starter once, talk about freaked out.

[mkernz22]

You realize the starter could be bad? I had that happen after my transmission swap. It had a dead spot so I swapped that out with the one I had laying around haha

[Box]

^^Of course the above. Things on cars like to die suddenly at times.

[Special_Edy]

First step is to determine if the starter works. There are two wires connected to the starter, one that is always receiving power from the battery and a smaller wire that makes the starter operate when you turn the key in the ignition(the solenoid wire). When you turn the key, 12 volts is sent thru the solenoid wire to tell the starter to start turning.
So to test the starter you will need to unplug the solenoid wire(look at the pic below, it has a black plug) and use a small piece of wire to short the battery terminal of either the starter or the positive side of the battery to the solenoid plug on the starter(touch it to the solenoid plug on the starter, not the wire from the ignition silly)
The starter will now start to spin nonstop until you remove the wire, if the starter is functioning correctly.

If the starter did not spin, it is a bad starter.
If the starter did spin, then either the starter relay or ignition switch are bad.(so go ahead and reconnect the starter like its supposed to be)




To test the starter relay and ignition switch-
First locate the starter relay inside the fusebox(it is located next to the battery alongside the driverside fender on my 94 GT)
In the pic below, it is the purple one(yours may be different)
Carefully pry the starter relay and the EFI? relay beside it out. You need a flat screwdriver or two to pry the tabs on the base of the relay so that you can wiggle it out.
Now swap the two relays(put them back in the opposite spots) and try to start the car. If the starter magically starts working then you have a bad relay. If the starter tested good and the relay swap did not fix it, then you have a bad ignition switch.







Hope this helps let me know if you need any clarification.

Also, Autozone can test starters on or off of the vehicle(better to remove it and let them test it on a bench)

hope this helps

Use the search button!

This post has been edited by Special_Edy: May 17, 2012 - 10:36 PM

[cajon]

First step is to determine if the starter works. There are two wires connected to the starter, one that is always receiving power from the battery and a smaller wire that makes the starter operate when you turn the key in the ignition(the solenoid wire). When you turn the key, 12 volts is sent thru the solenoid wire to tell the starter to start turning.
So to test the starter you will need to unplug the solenoid wire(look at the pic below, it has a black plug) and use a small piece of wire to short the battery terminal of either the starter or the positive side of the battery to the solenoid plug on the starter(touch it to the solenoid plug on the starter, not the wire from the ignition silly)
The starter will now start to spin nonstop until you remove the wire, if the starter is functioning correctly.

If the starter did not spin, it is a bad starter.
If the starter did spin, then either the starter relay or ignition switch are bad.(so go ahead and reconnect the starter like its supposed to be)




To test the starter relay and ignition switch-
First locate the starter relay inside the fusebox(it is located next to the battery alongside the driverside fender on my 94 GT)
In the pic below, it is the purple one(yours may be different)
Carefully pry the starter relay and the EFI? relay beside it out. You need a flat screwdriver or two to pry the tabs on the base of the relay so that you can wiggle it out.
Now swap the two relays(put them back in the opposite spots) and try to start the car. If the starter magically starts working then you have a bad relay. If the starter tested good and the relay swap did not fix it, then you have a bad ignition switch.







Hope this helps let me know if you need any clarification.

Also, Autozone can test starters on or off of the vehicle(better to remove it and let them test it on a bench)

hope this helps

Use the search button!

Thanks, Ill work through those steps till I find the bug.

Ground to starter perhaps? Ignition switch. If it's an automatic, could be a neutral safety switch acting up. Would be something along those lines if the starter isn't even bumping over. Odds are it's something simple. I forgot to attach the ground to a starter once, talk about freaked out.

Thanks, Ill look into it.

[rave2n]

Were the engines within the same year range for OBDI and OBDII?

[cajon]

Were the engines within the same year range for OBDI and OBDII?

not sure what that is. can you explain a little?

[solidxsnake]

Are the engines pre-1995, or post-1996? OBDI engines were around through 1995. '96 saw the introduction of OBDII, and this changed some of the sensors/electronics with the engine.

[stephen_lee]

Was the wiring harness swapped from the old engine to the new one? if the harness is auto and the car is manual (or vice versa) the starter circuit will not work

[cajon]

My car is a 94, idk what year the "new" engine is(engine #2). It looks newer than the old engine(engine #1), I do know that the the injectors are in diff places. On #1 they go into the intake, and on #2 they go into the head itself. Also, there are a couple plugs coming from the cars harness that I cant find homes for. So I'm thinking that Ive got a OBDII. I need help, Ive got to get this thing running. What are some of the diff between the two?

[Smaay]

the above picture is labeled a little wrong. the small plug is actually a ground. the large plug is constant 12V straight from the battery. when you turn the key the starter relay actually completes the circuit and grounds the starter. so unless you are turning the key, the small plug on the starter is floating.

[stephen_lee]

small plug may be a ground.. but when it cranks its +12v

[Bitter]

Small wire is power from the igniton/starter relay. The whole stater grounds to the engine/trans. Small wire is + for solenoid.



This post has been edited by Bitter: Jun 23, 2012 - 11:55 PM