88' Ranger cranks but wont start??

[atvkid4eva]

Hey guys the other day while i was driving down the freeway my check engine light started flashing and my truck attempted to shut off i quickly pushed in the clutch and pull over it smelled weird out of the exhaust but it started back up and drove for a couple more miles and then the CEL flashed again and it just completely shut off. It has fuel pressure and both pumps r working fine. It also has a very strong spark..it will crank all day but never fire. The only difference i can notice is when i go to start the truck the CEL dosent momentarily come on like it usually does when you start the truck? could it be my computer?

 

[atvkid4eva]

anyone know what would cause my CEL to not initially illuminate when i try and start the truck? i think the problem with it not starting lies in the same area as the CEL not turning on maybe the computer?

 

[atvkid4eva]

ok so i thought maybe the tfi module so i took it off and had it tested...it passed a bunch of times. so i sprayed some ether in it and it ran off ether? which is weird because i have fuel coming from the frame rail when i push the schrader valve in and i can hear both fuel pumps working? any ideas?

 

[kimcrwbr1]

If it runs off ether and you are sure the fuel pressure is good then the injectors arent getting a pulse voltage. Turn the ignition on and check for power to the injectors. The computer controls the ground. Clean all the ground wires you can find pull them apart and sand them metal to metal and clean all the connectors, pull the connector off the computer and look for corrosion. My 83 had a leak dripping on the computer on the passenger side door jam. Get a computer from the bone yard or a known good one and see if it runs just make sure the computer you get is for the same tranny you have.

 

[atvkid4eva]

im thinking the same thing since my CEL doesnt come on anymore with the key in the accesory position..i will check for power to the injectors in the next couple days. thanks!

 

[atvkid4eva]

ok well i just hooked a volt meter up to the injector plug and with the key in accesory mode it has a constant 12v..does that mean the computer it signaling the injectors? arent they suppost to have a pulse charge not a constant charge? idk guys is there anyway to check the computer for signal? any help would be great and give me somewhere to start. im lost.

 

[kimcrwbr1]

The computer controls the ground to the injectors I am not sure about you getting power to the injectors with the key on accy. Turn the key to the start position and check for power to the injectors. I guess you can hook the volt ohm meter to the injectors make sure the pos is on the power side and the neg on the other and see if you get a pulse when you crank on it. You will need to disconnect the injector to find the power side then crank on it. Or you can set a long extension/screwdriver on the injector and put your ear up to it and see it it is clicking. The poor mans stethescope it also works for listening to alot of things a bad bearing lifters a remote start button is nice just be careful of moving parts.

 

[kimcrwbr1]

I meant to the run position sorry

 

[n_grimm]

Going along with the good advice given above, you might want to try reseating the TFI connector. As I understand it, that is where the ECU gets a signal that the engine is cranking and thereby fires the injectors. Do the fuel pumps continue to run while you are cranking?

 

[atvkid4eva]

yes i can hear both the ums running while i am cranking the motor over...i had the TFI tested about 10 times and it passed on the machine at advance auto. so idk?

 

[n_grimm]

Since the ecu turns the fuel pump on, you know it is working except for providing injector pulses. You should be able to see the voltage on one side of the injectors going up and down a little while cranking, of course the other side is connected directly to 12 volts so it won't fluctuate as much. If you don't see that, I think I would remove the battery cable and remove the ecu, checking for corrosion and put it back in to see if that helps. Also, do you know how to pull codes? (If the ecu is able that is) Are they able to check the ecu locally?

 

[atvkid4eva]

i know how to on OBD2 but never on an older truck..i dont even see a port to plug a machine into under the dash?

 

[mhughes165]

thats because it isnt under the dash, its in the engine bay, on the passenger side fenderwell, should be a cover over it and the relays if it hasnt already been removed, or itll be in that general area, u can look in the tech library on how to jumper it and read the codes

 

[atvkid4eva]

Thanks could you post the link for me? im totally new to the pre OBDII..

 

[atvkid4eva]

also dosent my CEL need to light up on the dash in order for me to read the codes? it dosent.