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Discussion Starter · #1 ·
Brother was driving on the highway, and according to him the check engine light came on and the car just started slowing down like he was in neutral.

Had the car towed back to our house, and I took the T7 dic out of my car and put it in his to test if it would start.

No Dice.

While on the side of the freeway I pulled a plug and it smelled of fuel. So I think the fuel side of things are okay.

Do the symptoms sound like a CPS failure? I was suprised as there hasn't been any warning as to an impending failure.

I figure I should probably check the fuel pump fuse for power as well as pulling his original DIC and seeing if a plug sparks.

Any advice?
 

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If the engine was very hot, I would suspect the CPS. If it starts after cooling down, it's pretty much proven.

If it still fails to start, you can remove the DIC and plugs, ground all of the plugs to the engine, then crank it over to see if the plugs fire.

Finally, a little starting fluid in the throttle body will determine of there is gas or not... Ron
 

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Discussion Starter · #4 ·
It turns over just fine.

And we took out the older battery that was in it and put in the new one we've had sitting around waiting for when it finally goes.

Made no difference.
 

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my CPS gave up incrementally too,

but I suppose another more abrupt failure mode is possible, it's kinda old, right?

Not too big a deal to find the wires and test it's value, but I can't remember the right one right now,

Someone will know,

John
 

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Crawl under the rear of the car and smack the fuel tank several times with a rubber hammer, 2x4, etc. Ghetto fuel pump test. Then see if it will start.
 

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Discussion Starter · #8 ·
Okay, I checked the voltage at the 32nd fuse for the fuel pump, when turned to on, there was 0V, when cranking there was between 2 and 2.5V. I cannot hear the fuel pump prime.

We pulled the DIC and grounded a plug, sparked fine.

Looks like we have a fuel related problem.

Since the voltage at the fuse is not up to snuff can I assume the fuel pump is not to blame?

Will a bad CPS prevent the fuel pump from relieving power?
 

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Discussion Starter · #11 ·
I'd still like to know,

"Will a bad CPS prevent the fuel pump from relieving power?"

I will try starting it with starter fluid. How do I go about doing so? I have the aerosol spray. (Where to spray exactly, how much to spray, etc)
 

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Spray a bunch right down the throttle body with the car off. Open the plate so it gets down in there.

Step back, start immediately. If it kicks, you have a fuel issue.

If it's a fuel problem, try the "hammer the tank" test. It's ID'd the problem many a time.
 

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Discussion Starter · #13 ·
Spray a bunch right down the throttle body with the car off. Open the plate so it gets down in there.

Step back, start immediately. If it kicks, you have a fuel issue.

If it's a fuel problem, try the "hammer the tank" test. It's ID'd the problem many a time.
Tried the starter spray, engine caught and ran for a few seconds. Looks like it's a fuel problem.
 

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Discussion Starter · #14 ·
Also tried measuring the resistance of the CPS connector, 1+2 gave me .565 KOhms or 565 Ohms, just what it should be. Which means, probably not the CPS.

When cranking tach does not move, which means, probably the CPS...

Now I don't know what to think... :confused:
 

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Discussion Starter · #16 ·
I measured power at Fuse 32 with 0 volts when switched to ON and 2.5 volts when cranking, shouldn't that value be much higher?
 

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Fuse 32 has one side connected to the Fuel Pump Relay, the other side goes direct to the pump.

I'm no fuel pump guru, but I'd wager that you definitely should have full voltage there with the car on. The only caveat is that the ECU has to tell the relay to close. I don't know how you'd get 2.5V there if you are measuring from 32 to ground - the relay is a simple switch. I suppose it could be damaged to the point that it only passes 2.5V, but that seems unlikely.

You could try changing the relay.
 

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Discussion Starter · #18 ·
Oh man I think I may hace figured out why I wasnt getting and voltage. I was measuring across the fuse, not to ground.

Anyways now that we've established Im an idiot Ill retest when I get home.

Thanks for bearing with me.
 

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Discussion Starter · #19 ·
Looks like the fuel pump is actually getting power.

So now I have to decide, replace the pump from the top or bottom.

Thoughts? I don't really have the equipment to cut the metal to enlarge the hole from the inside. And this is a California car so rust is presumably not an issue. So I'm more swinging towards dropping the gas tank.
 

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If you drop the tank, you'll have to get most of the gas out. At approximately 7 lbs/gallon a full tank would have 112 lbs of gas in it. Then, you will need to drop all of the flexible fuel lines from their "flexible keepers" on the passenger side of the car. If the j-bolts loosen, then the tank will drop. I would use a transmission jack to lower it. Once it's on the ground, you will need to keep it from moving while you remove the fuel pump assembly locking ring.

Or, you could go to Harbor freight and buy a 4" die grinder for $20 and cut the hole in 5 minutes... Ron
 
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