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Discussion Starter · #1 ·
This is a 93.5 original NA/Auto that was GTE/T56 swapped, then put back to GE/W58 and never completed. I've been told it's an MKIV harness and based on the badging an SC/GS motor. At this point, it's nearly back together but there's several loose plugs and wires in the engine bay on the driver side and just looking for some guidance on where they go or need extended to. The car cranks but won't start. Thanks in advance for any help fellas. (Yes, it's dirty, dusty and grimey, I just received the car today so I haven't had my way with the degreasers yet.)

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1987 MA71 R154 Pearl White, Blue Velour
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I have a 7M-GTE, but I am currently doing work on my VSVs. That first picture of yours appears to be your CORRECTED EDIT FPR VSV. In my diagram, its the one with the blue lines



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The other lines look like ones to water temp sensors, possibly knock sensors.

Someone with a MK4 might be able to help you more.
 

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Close, but the first pic is the FPR VSV (blue lines in the 7M-GE diagram you posted) as it's connected directly between vacuum and the stock FPR.

My Father's got a stock-engine SC300 grocery getter that's still intact and running (will be swapped over the winter, though) I'll check on the rest on that car as soon as I can, but that might take a couple days.
Single wire plugs are usually gauge connections or simple things like that.
 
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1987 MA71 R154 Pearl White, Blue Velour
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@Wreckless Doh, you're correct. It was late and as I eyeballed the picture I saw an EGR :rolleyes: That said I thought it was out of place.

Oh, btw I don't know if you saw my post yesterday, but replacing my OBS VSV last night, which also fixed a vacuum leak as the tee had broken off, seems to have fixed my Code 52 that I was working on last week. :unsure:
 

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It been a while since I had to do my loom in that area, but if they reach under the intake manifold, one might be the front knock sensor, and the other for the oil pressure sensor above the AC pump
 

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Discussion Starter · #6 ·
Thanks guys, you were all right on the money! So after speaking with the previous owner, I believe the first picture is a Fuel Pressure Up solenoid, not sure if I need that or if its a CA car thing but, its unplugged and nothing nearby to plug it into. The bare terminals are for the oil level sensor that I did look down and see two bare wires for as well so, I can order the plugs and get that sorted. The last picture with the single pins are for either the knock sensor and/or coolant temp sensor. The others are oil pressure, power steering and apparently an alarm horn plug. I also have a naked crank sensor plug at the oil pump but don't think this harness/ecu uses it being an OBD1 distributor car.

All that being said, none of these are needed to get it to start so I'm still stuck at cranking. I can hear the fuel pump turning on and fuel rushing through the rail but its either not pulsing at the injector or I have an ignition problem. I ran out of time to dig in any further this week but I'll see if I can update this when I figure it out in case someone searches in the future.
 

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Having just replaced my Fuel Pressure Up VSV, i can say that yes the car will run, but it runs much better now that I've swapped it out. Also not nearly as rich smelling.

I recently had an issue with the wiring to my CPS. I had taken it apart to clean last summer and it ran great. One day it would not start anymore. Only cranking

I finally discovered that jiggling the wire harness going to the CPS "fixed" it. Obviously not a permanent fix, but I was able to pinpoint that as the failure. It has run great since.

Do you smell gas after you try to crank? Do you get weird "sort of" semi starts? Those were my symptoms until I fixed the CPS connection.
 

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Discussion Starter · #8 ·
Having just replaced my Fuel Pressure Up VSV, i can say that yes the car will run, but it runs much better now that I've swapped it out. Also not nearly as rich smelling.

I recently had an issue with the wiring to my CPS. I had taken it apart to clean last summer and it ran great. One day it would not start anymore. Only cranking

I finally discovered that jiggling the wire harness going to the CPS "fixed" it. Obviously not a permanent fix, but I was able to pinpoint that as the failure. It has run great since.

Do you smell gas after you try to crank? Do you get weird "sort of" semi starts? Those were my symptoms until I fixed the CPS connection.
I do smell gas and have the semi starts, its as if it wants to start but cant. This is an NA distributor car so I'll look towards the dizzy, plugs and wires for now. Its unfortunate too, I have everything I need to perform the GTE ECU mod but, I feel its smarter to get it running as-is, before starting the wiring in case I need to troubleshoot my install of all of that, maybe @Ali_SC3 can chime in for this.
 

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The fuel pressure up vsv wasn't on all the early GEs, just some cali spec and later years that were obd2 had them if I remember right.
It opens that vacuum line to air after a hot start to show the FPR ambient pressure which bumps up the fuel pressure temporarily as hot starts run lean which wont light off the cat = bad for emissions.
It wouldn't cause a no start or anything though, the fpr is at ambient when you go to start the car anyways.

My first instinct with loose wires in that area is check the main coolant sensor, if that is not working the engine wont see it as cold and usually shows up as a hard time starting.
It is pretty easy to tweak or even break that sensor when you are taking off the connector or stuff in that area in general.
Make sure you have the 2 wire main ecu coolant sensor connected, and you absolutely do need that sensor to have a good start.
The 1 wire coolant sensor next to the main one goes to the gauge cluster, and won't affect the start but is needed for the gauge.

If that doesn't do it I would also go over the ignition system, change the cap and rotor with toyota parts, put the motor at TDC and restab the distributor if you don't know for sure it is in the right position, some people like to remove it and don't place it back in the same spot. Maybe some fresh plugs and make sure you have good gas.

Ecus are getting older and could be an ecu issue even, I would suspect a cali spec ecu goes with that harness to be 100% correct. Make sure you are getting the CEL at key on for a sec, and try and jumper the diagnostic port for codes and make sure it still responds even if there are no codes, if there are codes those would be good to pull.
 

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Discussion Starter · #10 ·
The fuel pressure up vsv wasn't on all the early GEs, just some cali spec and later years that were obd2 had them if I remember right.
It opens that vacuum line to air after a hot start to show the FPR ambient pressure which bumps up the fuel pressure temporarily as hot starts run lean which wont light off the cat = bad for emissions.
It wouldn't cause a no start or anything though, the fpr is at ambient when you go to start the car anyways.

My first instinct with loose wires in that area is check the main coolant sensor, if that is not working the engine wont see it as cold and usually shows up as a hard time starting.
It is pretty easy to tweak or even break that sensor when you are taking off the connector or stuff in that area in general.
Also it looks like that 2 wire connector is the one for the coolant sensor, and you absolutely do need that sensor to have a good start.

I would also go over the ignition system, change the cap and rotor with toyota parts, put the motor at TDC and restab the distributor if you don't know for sure it is in the right position, some people like to remove it and don't place it back in the same spot. Maybe some fresh plugs and make sure you have good gas.

Ecus are getting older and could be an ecu issue even, I would suspect a cali spec ecu goes with that harness to be 100% correct. Make sure you are getting the CEL at key on for a sec, and try and jumper the diagnostic port for codes and make sure it still responds even if there are no codes, if there are codes those would be good to pull.
Thank you so much, that gives me plenty to work with, fingers crossed it starts this weekend.
 

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Actually the connector for the coolant sensor looks different now that I have had some coffee. make sure it is plugged in though. You only need a few things to be working sensor wise to get it to start and coolant temp is one of them.
 
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