Need help with Several problems

j_manuel7

Registered User
Hi! I need help with several issues with my 1990 T-Bird SC. This is the first T-Bird SC Car I have. I just overhauled the engine and added some modifications:

1. 7% Overdrive supercharger pulley
2. 38 lbs / hr injectors (I understand factory injectors are 32 lbs / hr)
3. 2% Overdrive jack shaft pulley
4. 75mm Throttle body
5. Comp Cams Rocker Roller arms (P/N 1619-12)
6. Comp Cams Pushrods set (P/N 7635-12)
7. Valve Springs, Guide Plates and shims
8. Comp Cams Camshaft P/N 44-701-9
9. Kooks mid length headers

These are the only modifications I made I just recently fired up the engine for the first time and observed the following issues:

1. When I start the engine it is not going into idle. It stays between 3,000 and 2,000 RPMs. At times the engine gets to 1,500 RPMs but it eventually ends up back between 2,000 and 3,000rpms.
2. I need a test method (other than smoke testing) to determine if I have a vacuum leak.
3. The computer is giving a code for throttle position sensor. I replaced the connector plug from this sensor because it was in very bad shape. I replaced it with a spare connector plug I had from another 1990 SC T-Bird and tried to follow the same color scheme to match the cables. I also replaced the throttle position sensor with a new one and still get the code for throttle position sensor. So I guess at this time I need the wiring identification (i.e. which color is ground, which is signal, etc.) to verify I properly connected the wires to the pins in the plug. Next I will need a method for properly testing the throttle position sensor and also the circuit.
4. The computer is also sending a code for the purge canister solenoid sensor. Where is this sensor located?
5. I need to know where is the coolant temp sensor since I’m also getting a code from the computer for this sensor. Is this sensor the one on the passenger side near the A/C Compressor or is this the one located at the water outlet next to the alternator.
6. Finally, when I fire up the engine, the headers are getting red hot. What is causing this? I research the internet for this problem and it seems this may be caused by rich or lean air / fuel mixture or timing. I did remove the spark plugs and these were covered in black carbon deposits.

Any help I can get will be greatly appreciated. Thanks!
 
1) Yes, you have a vacuum leak. Other than smoke testing, I can only suggest walking ALL the vacuum lines.

2) See #1

3) Have you checked the wiring diagrams in the EVTM (Electrical Vacuum Troubleshooting Manual) for a 1990? No? Don't have one? GET ONE. They're quite often up on Ebay.

4) For this, I'd also check both the EVTM and the Ford Factory Service Manual (see note about Ebay).

5) The 1-wire is the gauge; the 2-wire is the ECT. The ECT is usually near the thermostat housing. BTW - If this is open, you'll get a very fast idle as the ECU tries to force more water through the jacket and the water pump to run faster.

6) I think it's more running rich; I see you subbed in 38lb injectors instead of the factory injectors; have you gotten a base tune for your ECU yet? If not, then ... well, there you are! (That MAY have to do with the fast idle also; but I bet not). Plus, that vacuum leak may be conversely driving it LEAN. Fix your vacuum, get the ECU taken care of, and then worry about the rest.

RwP
 
The ECT is usually near the thermostat housing.

I believe the wire/sender near the thermostat housing is for the temp gauge. The ECT sensor is usually up top, on the other side, near the oil fill cap/front of the pass. valve cover, near the A/C compressor pulley.

Ken
 
3) Have you checked the wiring diagrams in the EVTM (Electrical Vacuum Troubleshooting Manual) for a 1990? No? Don't have one? GET ONE. They're quite often up on Ebay.


RwP

Don't know why, but this made me laugh harder than it should have...but seriously, the EVTM and Service Manual are a huge help, even if you just want to know how these dang cars work/light reading. I picked up both at Carlisle this year, 40 bucks for the set, and they're like brand new.

Good luck.
 
Ecu

have you gotten a base tune for your ECU yet?

First of all thank you for the input. How do I go about tuning the ECU? I research some info on the ECU for these cars and everyone have told me I have to replace the ECU since it is not programmable. Where can I get a programmable ECU for these cars?
 
have you gotten a base tune for your ECU yet?

First of all thank you for the input. How do I go about tuning the ECU? I research some info on the ECU for these cars and everyone have told me I have to replace the ECU since it is not programmable. Where can I get a programmable ECU for these cars?

Ummm ....

I'd've thought that the Moates Quarterhorse would have been obvious from the tuning threads ...

http://www.moates.net/quarterhorse-for-fords-p-199.html?cPath=63

HOWEVER.

It would be better to talk to a programmer like David Dalke or whoever you pick and pick it up from them with a base tune.

The other way is to pick up the Quarterhorse, and using the hints here (and on TCCoA!) find the catch code, find the proper strategy file, pick up Binary Editor, and go to town on programming it yourself.

(The QH is a good idea just for MONITORING; it exposes even more of what the ECU is doing than the OBDII connector does!)

RwP
 
Thank

Thanks for the info. I was fixing other problems the car had before attending this tuning issue. Hopefully I will get to it in the weekend.
 
In lieu of getting a tune, a "calibrated" MAF (mass air flow) housing would be a more logical first step. A real tune will always be the best for performance and flexibility, but for simplicity's sake, a 76mm C&L MAF with the proper sample tube (a purple tube works with 1990 SC's & 42# injectors...I think orange is for 36#). I just realized the C&L is out of business, but SupercoupePerformance.com has an equivalent (but more attractive) MAF housing....

From Supercoupe Performance....

https://www.supercoupeperformance.com/76mm-mass-air-flow-housing-same-as-cl

This will get you going for less $$ and less struggle than a tune....although, I do highly recommend you consider a Moates Quarterhorse & tune in the future!!

Another option is to put your stock injectors back in the motor for now. If they're the same as the US/Canada cars, they have red bodies and are rated at 30#/hr.
 
Thanks

Thanks for the input. Funny thing is I already have the MAF housing with the sampling tube and everything which I bought from Bill at supercoupe performance, but I'm still having problems. The factory injectors were in really bad shape when I took them out. They were corroded and two of them were beyond salvation. So at this point I got no other choice other than tuning the engine with the set up that I've got. Unless I can find some used factory injectors that is. I took a look at the moates quarter house site, but boy did I got confused. Guess I have to go to a local tuning shop here and try having them to explain me all that stuff at the moates website. Regards.
 
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In lieu of getting a tune, a "calibrated" MAF (mass air flow) housing would be a more logical first step. A real tune will always be the best for performance and flexibility, but for simplicity's sake, a 76mm C&L MAF with the proper sample tube (a purple tube works with 1990 SC's & 42# injectors...I think orange is for 36#). I just realized the C&L is out of business, but SupercoupePerformance.com has an equivalent (but more attractive) MAF housing....

From Supercoupe Performance....

https://www.supercoupeperformance.com/76mm-mass-air-flow-housing-same-as-cl

This will get you going for less $$ and less struggle than a tune....although, I do highly recommend you consider a Moates Quarterhorse & tune in the future!!

Another option is to put your stock injectors back in the motor for now. If they're the same as the US/Canada cars, they have red bodies and are rated at 30#/hr.


So I just got back at my project after 2 major Hurricanes swept the area where I live. I had no electricity for 100 days and no access to the internet. That sucked. Anyway, like I said I'm back at my project and I would like to have my car up and running for now, until I decide how to move forward with tuning my computer. Dr.Fishbone, you proposed that I should switch back to the stock injectors while I solve the computer tuning issue. However, since I made some modifications to the engine intake (Throttle body, camshaft, etc. please refer to the original post), I was wondering if the car will still run OK if I switch back to the stock injectors. Regards.
 
Regret I can not help with the tuning. Glad you are back. Hope the worse is in the rear view mirror.
Creighton
 
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