ranger wont start

[Maglov12]

i have a 1988 for ranger 2.9L that wont start and its high pressure fuel pump wont shut off. i cut the harness on fuel pump relay to install a new harness and relay and before instaling i noticed my truck has no spark wat so ever. i was woundering if the fuel pump relay had to be connected to activate a spark in the truck

 

[mn_smokeater]

any updates?

 

[Nhaz]

May sound stupid but I gotta ask. Did you disconnect the battery before cutting into the harness? If you didn't you may have blown a fuse or shorted something.

 

[Psychopete]

See my post about the fuel pump relay in your other thread.

Really recommend an EVTM so you can wrap your mind around how all of this works.

I have an '89 diagram of this which is real close, but wiring colors are different.

Divorced this out of an online diagram -

THIS IS HOW IT WORKS, BUT YOUR WIRING COLORS WILL BE DIFFERENT!!!
(disclaimer)

22, 8, 1, 60 are computer pins -
22 is fuel pump relay ground to turn it on,
8 is fuel pump monitor if equipped, computer monitors voltage to pump,
1 is computer main power,
60 is a ground.

 

[Maglov12]

first fuel relay and now no sparkplug spark

my mechanic is the one who disconnected the harness. im not sure if he disconnected the batteryt first or not but he took care of disconnecting it. he also ran tests on the truck and said he couldnt get any codes so he has no idea what is wrong with the truck and said he would inspect the truck by hands but his estimate is in the thousands if he cant find the problem right away. thanks for your help with diagram. i got a ranger book to help with installing the harness and still no power. fuel pump relay is brand new so im clueless. and whats really wierd is im now getting no sparkplug spark. could my distributor be bad? i checkd the TFI and thats working fine but how do you check the distributor to see if its working properly? please help

 

[Maglov12]

i was just messing with the harness and noticed that when i touch the power wire with high pressure fuel pump the pump ran. but when i connected the intank fuel pump to the power wire there was nothing also when the harness is connected and the relay is in place i get nothing. both the pumps are brand new installed just a month ago.

 

[Psychopete]

The wires are kind of similar, you should be able to figure out what is what with a volt meter -

My 1988 Ford Ranger/BII EVTM says:

Yellow wire is fused power for the relay and computer (pin #1) - hot.
Fuel pump fused power is also a yellow wire, but a completely different one with the same amperage fuse link - hot.

BK/LG is the computer relay ground.

R/LG is 12 volts from the ignition switch to the computer relay.

Red is power to the fuel pump relay switch side - hot when key is on.

T/LG is the computer relay ground switch side - this is what controls the fuel pumps. - Computer grounds, relay flows power to the pumps.

O/LB is to the fuel pumps - hot when computer grounds the fuel pump relay.



check if computer relay is getting fused power,
if it is, check the red wire for 12 volts on the fuel pump relay harness,

might also check if you're getting a signal from the ignition at the computer relay harness,

check the fused power for the fuel pump relay on the fuel pump harness that you have 12 volts,

check the computer relay ground,

There's a spot on the diagnostic connector that you can ground and supplement the T/LG that trips on the fuel pumps, but if you're not getting any spark, you problem is likely a fuse link, or maybe something with the computer relay (did the small ground connector get disconnected from the battery?).

 

[Maglov12]

thanks i just checked the Red wire (is power to the fuel pump relay switch side) im geting no power wat so ever. so the reason the fuel pump relay isnt working is becouse it has no power right?

 

[Maglov12]

thanks for your help i got the harness fixed and the pumps are woking fine again. i still have no spark but at least i got one thing out of the way.

 

[Maglov12]

still no spark in truck. ive changed all the sparkplugs and wires, as well as the colenoid. I retested the TFI unit that connects to the distributor and its working fine. im thinking of replacing the distributor itself and then work from there. any ideas before i jump into that project?

 

[Psychopete]

Are you getting power 12v+ to the coil but nothing out of the coil itself? Sometimes corrosion can build up in the connector and cause a bad connection here - it can be bad connection to the + side or even the negative that causes the coil to spark. Tach would verify if you are getting signal on the negative side from the TFI.

Have you seen this article yet? Might have something else to try -

http://www.therangerstation.com/tech_library/TFI_Diagnostic.html

 

[Maglov12]

ok i checked out the sight u showed and ran as many tests as possible. some of the stuff i didnt understand thats why i didnt get to them all. what i learned is that i am geting enough volts through the coil to the distributor cap to atleast get a spark. i am also geting great voltage to the tfi unit. ive tested the tfi unit a few times and its still working great. the only thing i havent tested is the distributor stator and the distributor itself. the truck was running perfect untill i didnt drive it for 2 days. then wen i went 2 start it up it was dead. my only question is, Is there any way you can short the distributor by jumpstarting the vehicle??? or is there any other part that im missing that could off gone up???

 

[Maglov12]

new computer fixed everything