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Discussion Starter · #1 ·
Well, today was the big day to see if the 302 EFI would fire up. It cranked and cranked but not even a sputter.

Background Facts:
I carefully did a wire diet but I left the engine harness (with the injector wires) untouched. I have not connected up the water temp sensor or the EGR vacuum regulator in case they come into play. Other electrics appear to work fine (lights and directionals).

I do hear the fuel pump run when I turn the ignition to the run position but it runs continuously.

With the HV coil wire disconnected I see a very healthy spark from the HV coil to the frame.

I checked one spark plug and it was dry.

I checked that little value on my fuel line (looks like a air value on a tire) and gas comes out of it if I push on the value as if I was letting air out of a tire.

I am guessing that perhaps my fuel injectors are not opening up because of a computer / wiring problem. I will check the wiring diagrams for ideas on what might prevent injectors from firing but I may be off on a while goose chase.

So I thought I would ask the experts here on the forum. Anyone have a suggestion for me?
 

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Snake Charmer
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You've checked that you don't have the timing wayyyyyy off. Did you do anything more than pull the donor engine?

All the rags out you used to block all the holes while the engine was sitting ? j/k

Throttle linkages correct ? The air/fuel mix is getting through the carb and into the cylinders ?

Have you checked that the plugs themselves are actually firing?

other than that .... good luck
 

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The fuel pump continuing to run is a question area. Key On Engine Off and the pump should run for a couple of seconds at most. Not sure why the computer would keep it running unless it thinks the car has started.

Fuel to the rails does not mean fuel into the cylinders. Injectors are expecting 30 lbs pressure and won't put enough in the to run if the pressure is low. Be sure you have enough gas in the tank. I know it sounds funny but there is a point at about 2 gallons that the fule will make it to the rails, but the engine won't run. No it was not my car
but I did see it.

Besides that my two cents is to look at the computer ground. Realize that a lot of the control ckts through the compter are being completed to ground by the computer so the faulty ground would wreck havoc.

best of luck



[ November 14, 2004, 05:11 PM: Message edited by: StephenP ]
 

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FFR Master Builder
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when you pushed in the fuel release valve was the fuel under alot of pressure. what confuses me is the pump is always running. i would check to see if you have enough fuel in the tank. you maybe sucking air with the fuel and not getting enough fuel pressure to work the injectors and make to fuel pump stop pumping.
have you got spark at the plugs. if not then it could be a rotor, cap or timing issue
 

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FFCobra Craftsman
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The fuel pump always running is a problem. The computer should turn the pump off after a second or two if the engine is not cranking or running. The fuel pump turning off has nothing to do with the amount of fuel in the tank or the fuel pressure in the line.
As far as the injectors not opening.....check the red wire at the injectors. It should have power with the ignition in run or start. The EEC applies a ground to the other wire when the injector should open.
 

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What everyone else said. The fuel pump should not continue to run after first turning on the key. My first guess is the system isn't getting up to pressure.
Pull the fuel line connection to the fuel rail (you're going to do this outside with a fire extinguisher ready) and see if the pump's pushing fuel.

Next things to check are grounds. 80% of early build electrical problems seem to be related to bad grounds. Did you hook up the computer's ground? Do the grounds have "good" connections? i.e. powdercoat removed etc.?

Good luck. Keep us posted.



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Discussion Starter · #7 ·
Thanks guys, you have given me something to work with. I believe all my grounds are in place but I can double check.

When I pushed in the fuel pressure relief value a lot of gas did not come spraying out. More like bubbled out.

I put about 2 gallons of gas in the tank. Before I did that I could here the pump sucking air. That noise one hears when they are down to the bottom of their soda.

I must have air in the line, but how does one get the air out of the line? I like the idea of disconnecting the fuel line and seeing if the pump is pushing gas. That would at least remove all air from the tank to the spot where I connect to the hard fuel rails.

I did not crank the engine more then a half a dozen times. Maybe I need to crank longer to remove the air.

I will also check to see the red wire has 12v applied to it when in the run position.
 

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As others have said the pump should not continue to run with the key on-engine off regardless of fuel level. It is based on a timer not a pressure sensor. Did you happen to do anything with the diagnostic connector when you did the wire diet? It should be left in. I would suggest you run the KOEO tests to see if you are getting any codes. Go here to find out how. It's fairly easy and all you need is an analog voltmeter and a jumper wire. Let us know what, if any, codes you get.

Cheers, Rod
 

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Discussion Starter · #9 ·
Thanks Rod, I will try KOEO tests. Before your post I checked and did have +12V at the injectors. I also ran the return line to a gas can and the pump was pushing gas through the return line. I also pinched the return line to see if the pump shut off when under pressure and it did not. It slowed down but did not shut off. Like you said the pump does not include a pressure sensor.

I did leave the diagnostic connect in place. I'll let you know how I make out with the KOEO codes.
 

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Discussion Starter · #10 ·
Thanks Rod, I will try KOEO tests. Before your post I checked and did have +12V at the injectors. I also ran the return line to a gas can and the pump was pushing gas through the return line. I also pinched the return line to see if the pump shut off when under pressure and it did not. It slowed down but did not shut off. Like you said the pump does not include a pressure sensor.

I did leave the diagnostic connect in place. I'll let you know how I make out with the KOEO codes.
 

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Discussion Starter · #11 ·
Opps sorry about those multiple posts...

I get no KOEO codes. As a matter of fact, the VIP connection is always hot. I am suspect of my computer wiring harness.

When I did the wire diet I removed very little from the computer harness because it was very hard to trace wires since their color codes did not appear to accurately match the wiring diagram I had. This was not the case when doing the dash board harness.

Now I am taking a closer look at that fuel pump circuit and there should be a pink / black wiring coming back from the fuel pump to the computer pin 19 via connector C201. This is probably the lead the tells the computer the pump is running. Pin 19 on the computer is going to a completely different connector (C135) then the one specified in the wiring diagram (C201). Now I am really confused. This wiring harness came out of a running donor.
 

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Are you absolutely sure you have the fuel line correct. I have seen a lot of people hook them up backwards. Make sure all the grounds are in the correct places. There is one by the soleniod that a lot of people mess up. If it is hot the pump usually will not pump but it is worth checking. PAB is a great source here for wiring stuff. HTH, Cheers Richard.
 

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I fI remember correctly, the fuel pump doesn't get grounded to the frame, it gets grounded to one of the wires going back to the computer, mine ran contiuously untill I discovered this. Also, if you listen closely, you should hear to audible "clicks" when you turn the keys. One is the fuel relay and the other is the computer relay, if the computer relay is not triggered the computer will get no power, and it probably wont be able to shut off the pump, or fire the engine...
 

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Discussion Starter · #15 ·
I definitely have power to the computer I can feel the ECC power relay click.

I have not found any unconnected grounds and have double checked the ones you guys suggested.

I have not located the fuel pump relay. I am not sure what I am looking for but from the wiring diagram I am guessing it is back by the fuel tank. Is it part of the the fuel pump?
 

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89 donor - the fuel pump relay is up front - mine is a green relay (89 as well). It is now behind the dash on the driver side.

The impact switch in the rear runs back up to the fuel pump relay. A year or two later and it breaks the HOT going to the fuel pump.

 

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Just to state the obvious, if you had the dist. out for any reason make sure you dropped it back in correctly, not 180 degrees off. Don't ask me how I know. But your no start symptoms sound very familiar.
Good Luck, Phil
 

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I'd like to jump in and give you some ideas. There is a definite problem if the pump runs all the time. If the relay were stuck and the pump runs all the time it should still start and run ok. One thing at a time. Self test, if it won't then fix that first!! Processor has to work if you want the engine to run. Don't even waste your time until you know you can do a KOEO test. Fuel squirting out of the schrader valve proves nothing. If you want to prove the pressure is ok you need a gauge to verify it. Make sure you are doing the KOEO test correctly.
Diagnostics go this way for no KOEO;
Verify VREF which is 5V output from processor to all 3 wire sensors. Pick the TP sensor, easiest to get to. Using ONLY a digtal meter measure the voltage between the O/W wire and BK/W wire with the key on, should be 5V. If you don't have 5V you need to verify the VREF or the ground is at fault. If you have 5V then you need to verify the continuity between the STI and STO terminals and the processor pins # 17 and #46. The STI wire is W/R and the STO is Tan.
Verify those things first before doing anything else. There really is a logical way to chase this. You may contact me if you would like a step by step. :D
 
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