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3.8 wont start

New guy here and i like this site! Who needs a Chilton's eh!  Anyway,  I've got a 3.8 87 t-bird i am trying to sell and all of a sudden it wont start today. it's been running fine till now but??????? it has a CFI system.  Should I be able to hear the fuel pump like a 2.3 turbo? I hear nothing when i turn the key on.  Are there common problems to look for on these cars when troubleshooting no starts? I dont know much about the CFI system....should i see a stream of fuel in the "carb"
when i open the throttle?
As a matter of background I bought the car to do a 351 swap but found an 88 turbo coupe i couldn't pass up, so this one's gotta go.
L24

3.8 wont start

Reply #1 –
when you turn on the key, a ground is supplied to the relay in the trunk via the tan wire.  the relay is located on the pass side area of the trunk.  if you dont hear it click, then it is not getting a ground from the eec.

tap on the relay with the key on and see if that helps.

next, use a rubber haammer to bang the bottom fo the fuel tank and see if that does the trick especially if the car has been sitting. 

report back

3.8 wont start

Reply #2 –
Make sure the inertia switch is pushed in (Its near the relay jcassity mentioned, passenger side of the trunk near the lid hinge).

And yea, when you turn the ign on you should here a click from the relay followed by noise from the fuel pump.
~Project ThunderStorm = '84 Charcoal Thunderbird - First Car - Long Time Work in Progress~
~Project (No Name Yet) = 1970 Plymouth GTX/RR "Clone"~

3.8 wont start

Reply #3 –
OK, just got home and did some quick troubleshooting. The solenoid is clicking.  I am getting 11.84 to the yellow wire.  I am also getting 11.84 volts across the inertia switch.  I am not however getting any volts to the pink/black wire going through the rubber grommet to the tank/fuel pump. The pump is not priming and i have zero PSI at the CFI. I am thinking pump or ground??? any thoughts??  Quick thought...It's a brand new battery but and I am going to jump it to try and get over 12v...i'll be back.

3.8 wont start

Reply #4 –
11.8 volts is enough to make it work.

When you say the solenoid is clicking, are you talking about the fuel pump relay?

If you have voltage on the yellow wire, then you should have the voltage on the pink/black wire if the fuel pump relay is picking.

When you put the ignition in RUN the fuel pump relay should pick for two seconds and then drop out.

To make it easier to trouble shoot, find the tan/light green wire at the self test connector under the hood. Jumper it to ground.
This should keep the fuel pump relay picked as long as the ignition is in RUN.

3.8 wont start

Reply #5 –
The relay is clicking and i am getting voltage everywhere except when i prick the pink wire under the grommet going to the fuel pump. I am not getting any volts there.

3.8 wont start

Reply #6 –
OK I just looked at your public profile and see you have a 88 Turbo Coupe. The wiring for those is different than the 3.8 and 5.0.

When you say you have voltage across the inertia switch If you mean:
1. Measuring from each side if the switch to ground you have voltage, that's good
2. If you mean measuring with a meter lead on each side of the switch and you have voltage, thats bad. It means the switch is open and needs resetting.

The wire you are probing at the tank is the same wire as the one on the output side of the inertia switch. But according to the 87 EVTM both the input and the output wires at the inertia switch are the same color. Pink/black
The diagram shows no connectors between the inertia switch and the fuel pump.

3.8 wont start

Reply #7 –
Ignore that previous post. I'm gonna start all over again.
OK it's an 87 3.8.

The other end of that pink wire is at the fuel pump relay. Did you probe it there?
There no connectors in the pink wire between the fuel pump relay and the fuel pump.

If you have voltage at one end and not the other of the pink wire then the wire is broken.

If you are sure the relay is picking and you don't have voltage on the pink wire at the relay then the relay is bad.

3.8 wont start

Reply #8 –
softtouch...thanks for the reply but check my original post.  I do indeed have an 88 Turbo but the car in question is my 87 3.8. Not to discount you but if the switch is open i should get out of limits which is bad as that shuts off 12v to the pump....closed would be 12V across the switch which would be good. i think you have that bassackwards.
  i replaced the relay and still no good....

3.8 wont start

Reply #9 –
Quote from: softtouch;183234
When you say you have voltage across the inertia switch If you mean:
1. Measuring from each side if the switch to ground you have voltage, that's good
2. If you mean measuring with a meter lead on each side of the switch and you have voltage, thats bad. It means the switch is open and needs resetting.


When taking voltage readings in electronic trouble shooting the term "across" means measuring as in #2 above. One meter lead on the input to the switch and the other meter lead on the output.

I am guessing you are hooking one lead to ground and probing with the other. As in #1 above.

Under what conditions are you taking these voltage readings?
During the two seconds that the EEC tries to run the pump with the ignition in RUN?
With the ignition in START while the engine is cranking?

Have you tried grounding the tan/green wire at the test connector?
This will take the EEC out of the picture.

Maybe this diagram will help you.

3.8 wont start

Reply #10 –
Let me start over.....with the ignition on, the relay is energising.  I measured volts at the relay......the yellow wire is getting constant 12V(key on/off) and the pink wire is getting 12V(key on). I then moved to the inertia switch.  with the key on i am getting 12V on both sides (one lead on the contact the other to ground) when i pull the switch it goes to out of limits, reset and again 12v. I even pulled the switch and Ohms checked it(.004Ohms). I replaced the relay anyway and the pump still wont prime so I think that leaves the pump or a ground to the pump? I am not too good at electrical stuff so i'm befuddled where the 12v stops. I will drop the tank and do a continuity check on the wiring. Thanks for the diagram, i'll use it tonight.  I think the car is broke because I put it in the paper tuesday.:beatyoass:

3.8 wont start

Reply #11 –
With voltage on the pink wire the pump should run.

The ground wire for the pump is orange.
Turn the key off and with your OHM meter check the orange wire for continuity to ground.

With voltage on the pink and ground on the orange and the pump doesn't run, the pump must be bad.

3.8 wont start

Reply #12 –
i figure that is the problem:mad:  oh well at least it aint full of gas! thanks for the help.
 

3.8 wont start

Reply #13 –
fixed it....the pump was bad.