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View Full Version : no spark or fuel pressure?!?



93thunderbird
01-15-2006, 10:06 PM
ok.. i have had low fuel pressure for a while now... and my CEL has come on for a good 2 weeks (hooked it to a scanner wouldnt let it do a "run test") finally 2days ago i pulled to a stop sign n it just shut off nice n smooth... (wouldnt restart, up shift light flickered, stayed on for only one time i tryed 2 crank) i pushed it into a parking lot.. next day i came back "0" fuel pressure.... no spark either, trys 2 turn over just dosnt... no up shift light ne more and i dont smell gas... im 85% sure i hear the pump whine... what do u think?

tbirdaj
01-15-2006, 11:49 PM
check the EEC ground by between the battery and the core support

bigjim44256
01-16-2006, 01:28 AM
checking the EEC ground is a good place to start but i wonder y u think u here the fuel pump whine but have no pressure. something is not right there. does ur fuel gage not work or r u hearing something else? also how do u know u dont have any spark? did u use a tester or did u do the " hold the boot close to a ground check"? u could very well have a bad crank sensor. if the pcm doesnt recieve a signal from this u will not have neither fuel or spark. try this. cycle the ignition to run, not start, and count three seconds. then turn it off and right back to run for three seconds. do this three or four times. this will make the pcm command the fuel pump on for start-up and u'll have a better idea of what is wrong.

RBH Racing
01-16-2006, 04:08 AM
lack of pressure could be the regulator gone bad, but that's not likely. Have you changed the fuel filter lately? They can collapse and create this exact issue.

As for the spark issue if it is trying to crank then it is getting some spark. Check your cam sensor and crank sensor. No doubt if that issue gets straight it will start and you can diagnose further and more accurately

Ray

BobGPz
01-16-2006, 11:51 AM
Doesn't the PCM shut off the fuel when there is no signal being sent by the crank sensor? I thought it did this for safety reasons..

7birdslater
01-16-2006, 02:34 PM
yes, no crank sensor means no fuel pump. Same is true with an LX distributor. I had one go bad on me once, and it took forever to diagnose. Turns out my distributor was shot and not triggering the fuel pump. I sudgest a fuel pressure guage and reading it while having someone cycle the key from run to off. If you have pressure when it goes to run, you have an ignition issue, probably crank sensor.

93thunderbird
01-16-2006, 03:24 PM
that main ground for the ecu checks out ok ...i have 0 pressure when i turn the key 2 the "on" position w/o starting... i have no pressure when doing it like u said turn it 2 the on then back then on still "0" pressure... i also did the hold the boot 2 a ground... (2 check the spark) (its a new cam sensor also,new filter,less then a month old,same with the dis mod) also new plugs n wires(x-mas :) ) that crank sensor n balancer are only about a yr n half old.. but i guess it could be the crank sensor even though the up shift arrow isnt on ...

RBH Racing
01-16-2006, 04:11 PM
test the fuel pump by grounding this terminal, with a jumper wire to any good ground. This will test most of the circuit, and make a definite decision on whether the pump is making any pressure.

93thunderbird
01-16-2006, 04:13 PM
? cum on lol what harness plug is that and location?

RBH Racing
01-16-2006, 04:19 PM
It's the EEC connector(diagnostic) connector, mounted behind the passenger side fender well. Should have a black or grey cap on it that says EEC IV. In the diagram it's called a self-test connector.

93thunderbird
01-16-2006, 06:28 PM
when i grounded it the pressure was 34ish still low but it did have pressure when jumping it... couldnt turn over batt. is near dead.. so what does this mean a relay is bad or the computer is shot?

BobGPz
01-16-2006, 08:24 PM
Maybe some hit the Fuel Cut Off Switch (Located in the trunk area). Hit the reset button and see if that works...

RBH Racing
01-16-2006, 08:36 PM
Really sounds like a bad cam or crank sensor man. I would go there first. If it happens to be something else you can always return the part.



BTW, 34 psi isn't all that bad on a dead battery.

93thunderbird
01-16-2006, 10:14 PM
it isnt tripped for me 2 "reset" it... no but about the fuel pressure, 24psi is right around were its at when driving and i let off the gas (anything past 40psi) it cuts out, cant be the cam(brand new motor) ne other test 2 narrow it down more.. (bad pump) etc?? or crank sensor?

93thunderbird
01-16-2006, 10:20 PM
could it be a relay thats bad or the ECU (thats bad?) i dont hear ne of them clicking

Duffy Floyd
01-16-2006, 11:29 PM
Assuming the Ignition swith is OK I would start by cheking the fuel pump relay. If the relay has high resistance in its contacts it could be causing a big voltage drop that is preventing the fuel pump from running at "full" speed and developing pressure. When the Ignition switch is placed in start the pump should run for about 3 seconds before getting shut off if the engine doesn't start.

bigjim44256
01-17-2006, 01:20 AM
in response to BobGPZ the PCM will shut off the fuel pump as a safety device but it will comand it on for about three seconds every time u cycle the key to run to build pressure for start-up. and as for the new engine that dont mean crap. ive installed sensors that were bad right out of the box. GM FWD wheel brgs come to mind, throwing the abs light. i wish i still worked at the ford garage but i dont so going from memory i believe the eec iv will run with the crank sensor only but will throw a check engine light if the cam sensor is bad. if the engine is running and the crank sensor goes out it will run off of the cam sensor until u shut it down and then it will not restart. but it would have thrown a light. if u had no CEL before it died ur crank and cam sensors should still be ok. u could have a bad eec relay but not likley. u still need to determine if ur getting spark and an injector pulse. u probably dont have a noid light but u should definatly be ably to make sure u have spark. start there. if u have spark for sure the eec is good and so is at least the crank sensor. tell us for sure if u have spark or not.

tbirdaj
01-17-2006, 02:10 AM
Homemade injector test light take a 194 wedge mini bulb available at most autoparts stores and bend the wires out plug the wires into the injector harness and if the light flashes you should be getting voltage

93thunderbird
01-17-2006, 11:24 AM
i had a CEL for 2 weeks.... (car wouldnt let it do a "run test" kept kicking it offline) finally it died (i have a new cam sensor in the car,was replaced less then 4 weeks ago) crank sensor is about 1yr n half old pls read all of this post, it said all of this....

bigjim44256
01-18-2006, 06:41 PM
ok what have u checked and what do u know? that suggestion about the home made noid light rocks i suggest using it. did u try cycling the key several times to see if it will build pressure? tell us this instead of telling us what u already said. out of curiosity were u using a scan tool or were u jumping the diagnostic connector? how were u going about getting ur codes? if u were using a scan tool and it wouldnt read anything or as u say it wouldnt do a run test a.k.a. Key on engine running(KOER). it should however be able to do a key on engine off(KOEO). if it was unable to perform either of these functions than i would say u have a bad PCM or a bad ground, maybe even a power but not likely.

93thunderbird
01-19-2006, 12:57 PM
so far when the car was running (b4 it died) i hooked it up 2 a scanner.... it threw 2 codes (anti-theft, mass air) ok i dont think i have anti theft also the mass air the wire was cut.. (fixed) CEL went off / 3 days later the CEL came back on (mass wires ok, car ran fine) well then driving it w/ the CEL on for 2 weeks it died (so far i havnt hooked it back to the scaner since it died) (up shift light not on when cranking) no spark "hold the boot 2 a ground" no fuel pressure (even try cycling the key several ) when "jumping" the diagnostic connector, i had fuel pressure as soon as i turned the key... (2day im going 2 change the PCM) the pcm is the black box by the air box right? i have an old one out of my 93 parts car hope it works (would have burnt out my PCM i had the fan hooked up 2 a toggle switch, may have burnt it out)

RBH Racing
01-19-2006, 02:03 PM
ANTI-THEFT?????:confused: :eek: :eek:


That would explain it all, but may take some research on what is in your pcm.

tbirdaj
01-19-2006, 03:02 PM
your eec is behind the passenger side kick panel behind the glove box

93thunderbird
01-19-2006, 04:07 PM
why did u tell me were my computer is in the car ? (maybe i didnt mean my pcm) the black box infront of my air box (controls,pump etc) the one that u can splice into to get the low speed fan 2 kick on, thats what i mean "pcm" but maybe thats not the correct "term" but thats what im going 2 change.. whats up with the anti-theft??? the car has keyless entry but it dosnt have a remote? (anti-theft light NEVER flashes) dont think i have an alarm (never went off lol)...

tbirdaj
01-19-2006, 04:11 PM
that box would be called the IRCM - Integrated Relay Control Module you should still be able to pull codes so something is leaning me towards bad wiring or bad eec

93thunderbird
01-19-2006, 05:57 PM
i changed the IRCM and guess what?! started right up! yes!(SOOO HAPPY) as soon as i put the new one in i turned the key and had fuel pressure (after jumping the batt.) fuel pressure still low (24 is at idle ) changed the fuel reg 2 times (ford one this time) im leaning tward leaky injector or weak pump... but CEL is still on? running really rich at start up... maybe a clogged cat or bad 02 sensor (dosnt crank over at first try,hasnt since low fuel pressure ) but i think that maybe due 2 lack of fuel pressure (if its sitting b4 i drive it and i turn the key 2 start it only jumps 2 about 34ish) what do you guys think?