stuwk1

Just finished my motor swap into my 87 gxl, still an N/a. Had the motor finally running last night after using the atf trick, but while it was running I had no rpm signal but other guages were working. After it stopped smoking I shut it off and removed the UIM intake manifold put the gasket on, bled the clutch, and put in different spark plugs. Tried to start it up this morning and have confirmed no spark. Rpm still has no signal , have checked my in car fuses as well as the egi fuse all seem ok. What really confuses me is that my leading coil is getting power found out by testing the white plug.

I checked the grounds to my frame by checking the long starter bolt with a strut tower bolt, it checked out. Battery is charged.

I even tried plugging in my secondary CAS with my plugs grounded on my frame and got nothing and couldnt hear my injectors clicking either, BUT i did the same thing yesterday before it started and I also didnt get anything so my secondary cas is probrably bad.

My coils are mounted with all bracked to the fenders.

dont know what else to check but need to get this car going.

stuwk1

Update just pulled the main relay and tested for continuity between connections and got nothing. Think its done, BUT i tried bridging the four connectors where it plugged in and still had no spark.

Assuming i bridged it right.

satch

iTrader: (1)

Does the four wire plug that runs to the Main Relay have constant voltage on the Black/Green wire and the White/Blue wire?

Does the Brown/White wire at the TPS or Pressure Sensor have 5 volts w/key to on. If it were to then it proves that the ECU is being powered up by the B/W wire that leaves the 4 wire plug from the Main Relay.

stuwk1

I was able to get ~12 volts with key off on both with one probe on the negative battery term. leme check the tps.

Electrical noob here, should i do the same with the tps? one probe in the 5v and one on one of the battery terminals with the key on?

satch

iTrader: (1)

Not sure what you mean by "one probe in the 5V," but if you're using a multimeter the Red meter lead goes to the wire you're measuring voltage from and the Black meter lead to a ground such as the negative battery terminal or the alternator housing. This would be done w/key to on if you are relying on the Main Relay to power the ECU, but if you bypass the relay via jumpering then the voltage sent to the ECU would be a constant/continous variety so no key would be necessary.

stuwk1

Thats what i meant the probe as the positive voltmeter wire. With the key on im getting 9.78 volts checked both tps and pressure sensor. with the key OFF im getting 10.78.

As a side note when my bridge is connected my shift up light is always on. This is how it was yesterday when my car actally started and my Main relay was connected, the light would stay on until it made a click and went off.

satch

iTrader: (1)

So you checked the same Brown/White colored wire at both the TPS and Pressure sensors and got close to 10 volts on each? If so this is well above what it should be. Pin 2A feeds this Brown/White wire from the ECU so you have something hooked up incorrectly or there is a problem in the wiring harness or the ground(s) for the ECU are suspect or the ECU is troubled. You might want to disconnect the five sensors connected to this Brown/White wire and then recheck the wire voltage. The TPS, Variable Resistor, Pressure Sensor, AFM and ATP are all connected to this wire.

stuwk1

Just played around with it for a minuite and without the bridge on the main relay im getting 5.6 volts on all brown and white connections.

satch

iTrader: (1)

What did you have to do to bring it down to the current level? You need to explain how the ECU is being powered up. Is it because you have the Main Relay hooked up properly or what, as one of the roles of this relay is to power up the ECU and if the relay is not hooked up properly or jumpered then the ECU cannot possibly be powered up thus the Brown/White wire could not possibly have voltage on it.

EDIT: There's only so many ways for the ECU to be powered up.

A). The Main Relay is hooked up and working properly and the key is to the on position.

B). The Main Relay is hooked up but one of the contacts or both contacts are stuck closed and powers up the ECU w/key to on and key to off.

C). The Main Relay is jumpered.


There is a 4 wire Green check connector located near the leading coil. One of the wires is Black/White. If this wire has voltage w/key to off then either the Main Relay is jumpered or the relay is connected properly but at least one of the contacts in the relay is stuck closed.

stuwk1

All i did was remove the wire that i used to jump the relay connection then i tested it with the key on and had 5 volts. Right now the relay is out of the car and the jumper is off and im getting 5 volts.

I placed the jumper on the main relay this morning after trying to rule it out and see if it was the reason i was not getting spark.

I will be checking that green pin mid afternoon tommorow.

satch

iTrader: (1)

With no relay connected and the 4 wire relay plug not jumpered it is not possible for the ECU to be powered up in a normal manner thus the Br/W wires could not have voltage so something out of the ordinary is at play here. One possibility is that you perhaps have the Main Relay and Starter Cut Relay confused. Main has two plugs and the Starter relay has but one plug to it w/four wires.

stuwk1

ha yep ive got those confused. ****. I guess that means i had the starter relay jumpered, but none the less with the key on and NOTHING jumpered i was reading 5 volts.

the four clip pin for this thing is what i had jumpered.

stuwk1

that is the main relay. I did have the main relay jumpered, something weird is going on.

satch

iTrader: (1)

If you did not have the Main Relay connected and you did not have the key to on do you still have voltage on the Br/W wire at the TPS. Also, what about the B/W wire at the check connector? Does it have any voltage w/no key?

stuwk1

At the green ccheck connector I've got 0.15 volts at the brown and white I've got 0.6 with key off.

satch

iTrader: (1)

But w/the key on are you using the Main Relay to power up the ECU or not? Or are you getting voltage readings on these two wires w/the key to on but the relay disconnected and not jumpered as well.

stuwk1

Main relay is out the car and not jumpered. The values in my last post is without the entire relay

satch

iTrader: (1)

But when you have voltage readings at these wires w/key to on is it when the Main Relay is being used or not?

stuwk1

The main relay is Not being used

satch

iTrader: (1)

You cannot very well have voltage on the B/W w/key to on w/o the Main Relay being used unless the White/Blue wire from the 30 amp Comp fuse or the Black/Green wire from the 40 amp INJ fuse is rubbing up against the B/W wire and passing its voltage on to the B/W wire. If you truly have battery voltage on the B/W wire at the check connector w/key to on and no relay being used then pull the 30 amp fuse and see if the voltage reading dies and if it doesn't die then pull the 40 amp fuse and see if the voltage dies or not.

stuwk1

None of the fuses changed the voltage WITHOUT the relay in car. It was reading about 5 constantly WITH key on.

stuwk1

However I was curious so i tried with the relay. and WITH the relay I was getting 12 volts WITH key on and when I pulled the comp fuse it went to 5 volts. When I shut the key Off it stayed at 5 volts until I removed the egi fuse again, and it would go back to 0.16 volts where it would stay even when the fuse was placed back in.

satch

iTrader: (1)

Oh boy. I'm going to give this one last shot. W/key to on and no Main Relay you have 5 volts on the B/W and Br/W wire. Correct?

stuwk1

As more food for thought, I plugged the main relay back in and am getting spark for the first crank then it stops and same with the needle on my tach it bumps once then stops

stuwk1

Yes that's correct