rosrex7

Just had an engine swap done and all is ok for the most part.


Upon starting the car i noticed that the Tach was inop.. Not only the one in the cluster but i have another tach on the dashboard and even the HKS turbo timer has a Tach function and they all read Zero..

I sat at the shop as they tried to troubledshoot it,. but couldnt find anything obvious.
I took it for a test drive and i tried to go WOT in 2nd and the boost guage almost did a full revolution im sure that it passed 20 PSI... again i took it back and everythihng seems to be connected properly
The turbos on my blown motor were already non-seq so i had those put back on the new motor plus i had to swap out the wiring harness anyway. I drove the car home anyway. and it ran good

So where do i start trying to find out what is messed up with the tach? since all of them are reading zero then what would be the initial source. The the crank sensor, the coils, the harness ECU??

Help..

Tom93R1

iTrader: (2)

Look where the harness comes through the firewall, there is a connector right there that is easy to forget to connect

C's-7

iTrader: (3)

+1. There is a white harness that will cause issues with the gauge cluster if it is not plugged in....and like mentioned above it is right at the ECU. Is the stock oil pressure gauge maxed out as well?

C's-7

iTrader: (3)

I should also mention that with this harness unplugged the tach will appear to be working as you turn over the car, but will drop to 0 once the engine has fired.

rosrex7

Yup those are my symptoms the oil pressure climbs when I accelerate and the tach drops as soon the engine fires I will take a look at the ecu side in the morning

I know my turbo problem isn't going to be as simple but is there anyway that the boost issue is related to that connection?

C's-7

iTrader: (3)

I believe the oil pressure gauge will max out completely. Does the odometer go out as well once the car fires?

dream_garage

iTrader: (8)

^^ dude, exactly what mine does, no tach, maxed out oil pressure gauge, and no odo. Gotta check that plug !!^^

rosrex7

***FIXED***


Turns out that it was some cut wires by the ECU
What happened was the are 2 wires that are jumped by two if those crimping connectors .. so either the mechanic yanked them through the firewall when they pulled out the engine. and just connected everything back up the Original way and forgot to put back on the other lines..


Thanks for pointing me in the right direction








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and you are entitled to one forum buck and a free post, redeemable on any thread of your choosing
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and its "seems" that the boost problem is fixed as well. May be the other wire that was cut

anyone know where i could get an ECU color code breakdown??
I got a yellow and blue with a brown stripe and a blue wire with a brown stripe
Im too scared to step on the gas again but it got to 13psi and i backed off of it..
but everything else seems to be in working order..

Tom93R1

iTrader: (2)

I think the factory service manual has wire color codes in it but I must say I cannot remember for certain.