fuel problem? car wont start need help asap!!!

[rapedbytheeves]

okay guys got a problem and ive tried looking for a solution before posting this and havent been able to find anything so here it goes... just got my 1990 eagle talon tsi about a week ago, had to replace all main brake lines, water outlet, tstat, and a few other things. the problem im having now is fuel related. the previous owner had a long wire connected to the fuel pump harness. the black with white striped wire which is the power wire i believe. it wasnt connected to anything and was just looped in he must have cut all the other wires too and did a hack job on them, before i touched them i started the car, after i cut them and rewired the harness matching the colors i tried starting... nothing, checked the wires again just to make sure and still nothing. then i cut them again striped, soldered and shrink taped em. still nothing. so i thought maybe they touched something and blew a fuse. however there are no fuses for the pump. pulled the pump out and tested to see if it was pumping and it was, put it back in and wired a 12v constant to a switch and tried running the pump that way and starting the car.... nothing. so i hooked up the harness and tested for volts. with the key on the ON position it showed about 0.08v with the car cranking it shows 7.6v-8.0v. i have spark and i believe fuel is getting to the rail. what else could it be??? if the fuel relay was shot wouldnt there be 0v to the pump? something like this happened to my girlfriends civic when the pump wasnt pushing out enough psi but it still started for about 3-5 seconds then died. my car doesnt even want to start. it just cranks. all my fuses are good checked over them twice. checked the wiring like 5 times. i cannot find anything on this on the net PLEASE HELP!!!!

 

[luv2rallye]

Make sure the all black wire at the pump has a good ground connection. They tend to rust or break off. Know that the pump only gets voltage while the engine is cranking or running - not when the key is ON and engine not rotating. Check voltage on the output black-green wire (pin 2) and the input black-white (pin 3) on the combination fuel pump/MPI control relay (has 2 relays inside).

 

[rapedbytheeves]

alright thanks a lot man now i know what im looking for. ill check that today and see how it goes

okay so i was home for a total of 10 minutes today, tried starting the car again and listened to see if the pump primed, when i turn the key to the on position it doesnt do anything, when i crank the car i think i hear it pumping, but as soon as i stop cranking the motor i hear the pump prime? since its priming shouldnt the mpi and fuel relay still be good?

 

[90on35psi]

Also, a Chilton's manual can help you alot. The procedures or grounding the pump to leak check the fuel system is in there which would help you meter the voltage too.

 

[rapedbytheeves]

yea i havent gotten around to picking one up yet ill just reground the pump and check voltage theres gotta be somewhere online that will tell me how to do it the same way

could it be the ecu? read somewhere that a guy was having a similar problem changed out the mpi and fuel relay and still nothing. turned out he wasnt getting power to pin 106 on the ecu or something like that so he just put a switch and 12v constant to it and started right up hasnt had a problem sence. im going back home today so ill check and see if the ecu is getting power, the car isnt throwing a CEL the CEL doesnt light up when the key turns to the ON position but the seat belt, coolant, battery and a couple others turn on just took a quick glance at that the other day so dont remember which ones lit up.

 

[90moneypit]

Well at a minimum I know the CEL bulb is burned out. It should light up when you first turn the key to the on position as part of the bulb check then go out once it starts up.
Just so we're clear, the engine DID run before you started messing with the wires or has it never run since you bought it? It sounds like there was some kind of work-around happening and you might want to ask the previous owner what was going on.
When you heard the pump 'priming', did the sound come from the engine bay, back of the car, or somewhere behind the radio? When a 1g ecu starts going out, you can hear a series of clicks when you turn the key off so you might want to pull it and give it a visual check inside the case. If nothing else, you probably want to know if it's an eprom ecu right?

 

[rapedbytheeves]

the car is stock, it did run when i bought it, the previous owner was going to run a fuel cut off switch and had a very long wire connected to the power wire (black w white strip) for the pump harness. i cut that out and wired it back up to stock. after that it hasnt started since. i dont have a radio in the car so it makes listening for noises very easy. when i turn the key to the on position there is no noise, when i turn and crank the car i can hear the pump and as soon as i let off cranking i hear the pump prime for about 2-3 seconds then clicks again once its done.

 

[90moneypit]

That sounds backwards. The pump should prime for 2-3 seconds after you turn the key to the on position not after you turn it off and then only if you haven't started the car for a while.

Check your wiring connections against a known good setup like the fuel pump rewire on vfaq.com to make sure you didn't accidentally cross a couple of them up. Check them against the colors on the other side of the plug to make sure someone didn't cross the pins there for some unknown reason. Check to see if someone changed the fuel pump and switched the polarity on the pump. Finally, check to see if you have a 90 ecu or a 91-94 ecu. To use a 91+ ecu, you have to swap pins 6 & 14. Pin 13 controls your fuel pump relay so someone might have miscounted and swapped the wrong one by accident.

That should cover most of the bases on the electrical front. Let us know how all that checks out!

 

[shibby1036]

bro im having the same problem with the newest 1st gen i just bought. this 17 year old kid did a hack job on the fuel system, and put a relay on top of the fuel pump acess plate. now i think he fried somethin. i checked everything with my multimeter and still nothing. mine wouldnt even turn on. my last guess is the mpi relay in the engine bay. as for right now i have my walbro on a a switch which is driving my turbo timer nutz!!!!. so your not the only one with this problem. do me a favor if you fix your problem let me in on the solution and same if i find it before you.
by the way i agree with the other guy. get a haynes or a chiltons. youll need it to know what ohms and volts to look for whe testing your relays.

 

[steve]

That sounds backwards. The pump should prime for 2-3 seconds after you turn the key to the on position not after you turn it off and then only if you haven't started the car for a while.

On a 1G there are two inputs for the fuel pump side of the MPI relay and they are directly related to the two ways the fuel pump is activated.

The first is a connection to the starter. When the wire to the starter solenoid is hot (electrically not temp) one of the coils in the relay gets power and since the other side is grounded the relay activates and the fuel pump turns on.

The second is a connection to the ECU. Like most of the other ECU connected devices, the ECU switches the wire to ground and the other side of the coil is connected to the power for the pump. The ECU turns the fuel pump on when it first sees CAS pulses and off after a short delay of not seeing them. This is why the pump continues running for a few seconds after you stop cranking assuming the CAS is working. Since it's undefined where the CAS is when you first turn the ignition on, the signal can glitch on power up and trick the ECU into thinking the engine is moving.

This is also the cause of the famous prime at key on that some people think is normal for a DSM but isn't.

 

[90moneypit]

On a 1G there are two inputs for the fuel pump side of the MPI relay and they are directly related to the two ways the fuel pump is activated.

The first is a connection to the starter. When the wire to the starter solenoid is hot (electrically not temp) one of the coils in the relay gets power and since the other side is grounded the relay activates and the fuel pump turns on.

The second is a connection to the ECU. Like most of the other ECU connected devices, the ECU switches the wire to ground and the other side of the coil is connected to the power for the pump. The ECU turns the fuel pump on when it first sees CAS pulses and off after a short delay of not seeing them. This is why the pump continues running for a few seconds after you stop cranking assuming the CAS is working. Since it's undefined where the CAS is when you first turn the ignition on, the signal can glitch on power up and trick the ECU into thinking the engine is moving.

This is also the cause of the famous prime at key on that some people think is normal for a DSM but isn't.

That's good to know. I thought mine stopped doing the 'pre-prime' when I rebuilt the engine and disconnected the fpr solenoid on the firewall (went aeromotive). Seems like every other FI car I've owned did the pre-prime to some extent or another, my thoughts were that it was establishing the correct fuel pressure as well as kicking in a little fuel to start. Then again, they all had stock fuel pumps so it's not as easy to hear as a 255 Wally so might have been something else.

 

[rapedbytheeves]

fixed the problem. i took out the sending unit and rewired all the connections, redid the ground on the top and snaked the power wire to the pump from the top of the sending unit a different way than it was originally. the previous owner had it setup weird and i was going off that too, when the sending unit was attached to the tank the power wire was crimped and was grounding out on the tank or the sending unit. i didnt think that was the problem since i was VERY careful on putting it back in. although i did have to wire the pump to a switch to get power to it. so heres exactly what i did:

rewired the sending unit to make sure the wires were not in contact with anything. ran an 8 guage power wire from my battery to a 30 amp relay i bought at radio shack. used a 10g ground from the relay, 10g ground for the pump, 10g wire for power from the relay to the pump. then put a switch in, ran 12v constant to that and from the switch to the relay. i have to turn the pump on and off everytime i start my car but i dont mind it. im just glad my car is running. now onto my brake problem.

the pedal gets stuck all the way up and is super stiff. my brakes sometimes stick on and i have to shut the car off, press on the brake and feel it release itself before i can start moving again. it did this when i blew a brake line and i replaced them. bled all the brakes and then my pedal went down too far before the brakes engaged. now all of a sudden they are getting stuck on again. im guessing its my right front caliper since that wheel is super hot and the car pulls to the right. the right rear is also making some noise now. and seems to get stiff. my E-brake light comes on and off so my ebrake cable might be sticking now too.

 

[Dansdsm121]

It sounds like your caliper is sticking on you. Try replacing the RF or(in my opinion) both LF and RF calipers and I think your problem will disappear.