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WTF SPFI swap ran yesterday now no start


Uberoo
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My EA81 SPFI swap ran great yesterday now I can't get it to start.I drove it into its parking spot yesterday.Go to start it today and it wont start.WTF? I have fuel.I should have spark,I have power to the coil and all that.I did nothing to it other than putting 1/2 doors on it.

 

I was able to get it started after a long time cranking and a ton of of starting fluid.Then I turned it off and I havent gotten it to start yet.

 

everything that is supposed to be hot is hot but still no start

 

I dont quite have the start wire hooked to anything right now which was why I was tring to start it.You know find the wire that when starting is hot, then tap into it.

 

To get it started before I just touched that wire to a 12V hot and it would start.Now even doing that it wont start.

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Check all your fuses, etc.

 

Actually check for spark?

 

Check the resistance of the CTS - it might be indicateing the engine is hot when it's actually cold leading to no cold enrichment and no starting.

 

The start wire is the one on the ignition switch connector that isn't being used. If you look at the switch side you will see 6 male spades but on the harness side there will only be 5 female spades. The 6th spade is the start signal - pop a female spade with short pig-tail from one of the unused connectors from the SPFI donor harness into the vehicle side of the plug and solder that to the start signal wire going to the ECU.

 

GD

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Im guessing its the CTS because the injector is not spraying.

 

as for the sixth wire,thats how I orinally had it yesterday.It would not start just connected to there...to get it to start before I ended up stripping the insulation off that wire were I connected it to the ecu then touching it to an exposed hot.

Edited by Uberoo
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HELP!!!!! replaced that switch/sensor and it still wont start!!!!

 

I have power everywhere I am supposed to when the key is in run .

 

Please help!!!! I need to get this going by Thursday!!!!

 

 

EDIT: Found out I am not getting any spark despite the fact that there is power to the coil(On both sides for some reason.I am not getting any power in the tower of the coil(according to my test light).I tried putting in a different coil same thing.

 

also does the computer have to grounded to the body or does it have it its own ground/s in the wiring harness?If the computer needs to be grounded that might be my problem because it is just stuffed under the dash,non bolted to anything.

Edited by Uberoo
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Sounds like your power supplies are messed up. Have you checked the fuses that you installed for the power supplies to the SPFI harness? There should be 1 fusible link, 1 constant hot fuse, and 2 ignition switched fuses for a total of 4 seperate power supplies to the harness in addition to the ignition switch "start signal" wire to the ECU (which technically should also be fused but I typically don't bother).

 

Power on both sides of the coil is normal - it is the interruption of the power that causes the secondary winding in the coil to charge and discharge. Not only does there need to be power at the coil, but also the ECU has to be turning the power to the coil on and off as the engine is being cranked. Sounds like the ECU is not giving that signal to me. Thus I would be checking the SPFI harness power leads to insure that the ECU and all the trimmings in the SPFI system have power where they should. After that you need to start checking grounds.

 

The ECU is not grounded except by it's ground pins and thus through the ground leads in the SPFI harness.

 

GD

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If its the same as an ej, (just an efi system) you need to get your ecu hot from a different source, like the black wire in the column plug. One drops voltage while cranking, not leaving enough for the ecu. I wired mine the same, tested w/ a dmm and was one(1) volt low, no start.

 

I hope you used the same gauge wires or larger and soldered them. Clips or crimps are ok for the tiny stuff but larger amperage stuff cook and gain resistance like a lightbulb would under your dash.

 

I really should start getting parts for this swap.

Edited by Yo'J
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It seems its just a wiring gremlin. I looked at stuff under the dash and just the act of messing stuff around allowed it to start.So possibly a loose connector or pin at the ecu or something..

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