thunderbird won't start, need help

[sparky huberman]

1990 t-bird 3.8v6 180,000mi. running normaly, parked for 4 days now won't start. turns over fine, will fire on starting fluid but won't stay running on it's own. new pugs, wires, cap and rotor, just to eliminate any of that. suspect it's fuel related. I can hear the pump come on when the key is on, (new fuel filter) and i checked the fuel press. at the port on the fuel rail. Supposed to be 35 - 45psi, it's just above the minimum at about 36psi.....any thoughts??

Any help would be greatly appreciated.

Sparky

 

[Big Bird Jr.]

Try holding the gas slightly and see if it will fire like that.

 

[sparky huberman]

Thanks for the suggestion, I've tried it with the throttle in all sorts of positions and it doesn't seem to make any difference. I'm wondering if the fuel pump may not be creating enough press. for the injectors to function properly, of if there is a fuel pressure regulator or sensor or ?????????

May end up being the process of elimination....replacing shit till it works!!!

Sparky

 

[Little J's 5.4]

My guess is that your battery may have been discharged when it was idele. Possibly it is having a hard time holding a load. You can try to do a Drain Test:

Check for current drains on the battery in excess of 50 milliamps with all the electrical accessories off and the vehicle at rest. Current drains can be tested with the following procedure.

WARNING: DO NOT ATTEMPT THIS TEST ON A LEAD-ACID BATTERY THAT HAS RECENTLY BEEN RECHARGED.

CAUTION: Do not crank the engine or operate accessories that draw more than 10A . You could open the fuse in the meter.

NOTE: Many computers draw 10 mA or more continuously.

With Multimeter Test Procedure

NOTE: Use an in-line ammeter between the battery positive or negative post and its respective cable.

1. Insert the test leads in the input terminals shown.
2. Turn switch to mA/A dc.
3. Disconnect battery terminal and touch probes.
4. Isolate circuit causing current drain by pulling out one fuse after another while reading the display.
5. Current reading will drop when the fuse on the bad circuit is pulled.
6. Reinstall fuse and test components (including connectors) of that circuit to find defective component(s).

The current reading (current drain) should be less than 0.05 amp. If it exceeds 0.05 amp, it indicates a constant current drain which could cause a discharged battery. Possible sources of current drain are vehicle lamps (such as underhood, glove compartment, luggage compartment) that do not shut off properly.

Electronic Drains Which Shut Off When the Battery Cable Is Disconnected


1. Repeat Steps 1 through 6 of the voltmeter drain testing.
2. Without starting engine, turn ignition ON for a moment and then OFF. If applicable, wait one minute for the illuminated entry lamps to turn off.
3. Connect the voltmeter and read the voltage. The current reading (current drain) should be less than 0.05 amp . If it exceeds 0.05 amp after a few minutes, and if this drain did not show in previous tests, the drain is most likely caused by a malfunctioning electronic component. As in previous tests, remove the fuses in fuse junction panel one at a time to locate the problem circuit.

 

[Big Bird 5.4]

Well, seems to me youre not getting fuel.... got sufficient pressure (anything 30 lbs or over)......Hmmmm? seems that next thing in line would be those injectors.... gummed up, or not getting signal.... I would check and see if the injectors are getting a signal with my trusty VOM, and then;
1.If getting signal, go to step 2. , otherwise its in your computer/ injector circuitry.
2. Gummed injectors , try replacing them as you cant clean them with no flow.... try a salvage yard, you cant go too far wrong picking up a set for pennies onn the dollar, or check with the guys on TCCOA... most have spare stuff lying around gathering dust...

 

[sparky huberman]

Thanks Big Bird, I"m thinking along the same lines as you. I'm assuming that checking the injectors for a signal is fairly straight forward but i've never done it before, can you elaborate? And who is TCCOA??.....Thanks again

Sparky

 

[Big Bird Jr.]

A noid light can indicate a signal is being transferred. Flashing while running means the injectors are pulsing, and that is good. Solid means that they are hung open(Common with the 94-95 4.6L's due to a bad EEC). No light means no signal.

www.tccoa.com

 

[Little J's 5.4]

tccoa is lame!!! :xpl:

If it was fuel related you should have had the problem before the car sat. Since the problem occurred after sitting for a while I suspect a drain in the battery. You can try charging it, getting a load test (some places offer it for free) or do what I describe above... :shrug:

 

[Big Bird 5.4]

tccoa is lame!!! :xpl:QUOTE]

aaaah! sour grapes. :banana: .. just cause youre banned, and I am a refugee from there.... every now and then they still come up with parts and such, even if they are rather narrow minded and "Old Boy Networkers"who let certain people get away with things that arent fair :bored: .... and allow favored individuals to cross the line :nonono: , but hey! I digress..... :rollseyes

 

[sparky huberman]

Thanks Big Bird, I'll give that a try. Little J, I understand the rational that if it was fuel related i should have been experiencing some symptoms before but in this age of sensors and such, i'm not so sure that it can't still be in the fuel delivery area. You keep heading down the drained battery path which i don't understand......it turns over fine, (always has) and i've had a charger on it just to keep it up to par during my ongoing attempts. Am i missing something that you're getting at????

Thanks to both of you for any suggestions

Sparky

 

[Little J's 5.4]

The electrical is more of a problem as your car gets newer. If there is not enough oomph in the battery the spark will be smaller and the car will act fuel starved. This is something I have seen with a 94+. It may be possible for an older car. I am not as familiar with the 5.0's as I am with the 4.6L's. Still, it can happen.

With problems I like to start with the obvious stuff like the battery and alternator. I would check the battery, then start here and check the battery terminals and make sure that there is at least 13 volts when the engine is running...

Then inspect the distributor, plugs, sensors, fuel injectors and the timing chain...

 

[sparky huberman]

OK little update....pulled one of the injector connections off and with just a test light, checked for power. With the key in the on position there is power to one of the terminals. while cranking the motor I would assume there would be a pulsing light from the other terminal (is this correct?) I have nothing while cranking other than a constant indication of power from the first terminal......any thoughts???

Thanks,

Sparky

 

[Big Bird 5.4]

bridge the terminals , you should get a pulsating lite on each injector.... sounds as tho thats your problem ... circuit between the puter and injectors.... .... I would bet the drivers for injectors in the 'puter are shot... time to start hitting salvage yards for a 'puter with your catch code...... :rollseyes

 

[sparky huberman]

Thanks Big Bird, I'll give that a try....

Sparky

 

[sparky huberman]

OK quick update, bridged the terminals on one injector plug with a test light, very weak light when engine is cranking over, doesn't appear to be in-sinc with what would be the firing of one particular cylinder. Also checked it with a volt meter and when cranking it's about 1 volt.............any thoughts????

Thanks

Sparky

 

[Little J's 5.4]

Battery hold a load? Are the injectors pulsing? Do you have spark? I hope the answer is not "yes" to all of the above. If so you have a jumped timing chain... :whine:

 

[Big Bird Jr.]

Well, he can start it with ether.... Did it shake and shudder when you did that?(I don't like ether... bad for pistons)

 

[sparky huberman]

Thanks for the input guys,
Battery is holding a charge, the timing chain was done not that long ago, and it does fire on ether.......i don't like doing that either but wanted to at least see if i could get it to fire. Doesn't seem to shake or shudder when running on the ether. I've double checked to make sure it's got a strong spark (thought it might fire on ether with a weak spark) by pulling a plug and grounding it against the exhaust manifold....seems strong. I also pulled a plug to see if it looks like it's getting fuel and it appears that it is.......Seems like that would be enough huh!!....I'm confused......perhaps something like the throttle position sensor......or mass air flow sensor.....or....???
I'll keep messing with it and if anyone has any more ideas, i'd be happy to hear them.

Thanks again

Sparky

 

[Little J's 5.4]

Who did your timing chain and are you sure it was done or that it was done correctly?

You can check the electrical?
Coil to cap wire resistance 7,000 ohms per foot maximum.
Primary (small terminals) Coil resistance 0.3 to 1.6 ohms.
Secondary Coil resistance (negative primary and secondary) 6.5 to 11.5 k-ohms.

Primary (positive primary) Coil winding to case of the coil 10 M-Ohms.

Battery engine off: 12 volts
Battery charging: 14-15 volts

You can always get an EEC like the old swabby suggested? They can be found at bone yards for $50... Sounds like the least expensive option if the wiring passes.. :beer: Else you are back to the chain... :cryying:

 

[Big Bird 5.4]

Well, sparky , it's been a while; Ya got that thing running yet? what was the problem in final analysis? It's allways nice to hear what finally happened, so dont leave us hanging......................... :nono: