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Old 09-14-2007, 02:28 AM   #1
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Default COIL OR FUEL PUMP

Alright here is how it all went. After driving for about 13 miles whenever i let off the gas the rpms would jump down and then back up about 300 rs it would keep doing this every like 3 seconds until i pressed on the gas. At first i figured the tourqe converter but it works just fine and even when i put it in first it will still do it. But now on my way to work it started doing it then it just flat out died on me. It wouldnt start after that so we towed it back to my house. I hit the fuel tank with a rubber mallet a few times and it started up so i thought it was the fuel pump but then cylinders 1 and 4 started missing. Come to find they dont have spark. Im wondering if both could have gone out at the same time or if its just bad wireing cause i dont have the money to blow on both. And the coils themselves dont spark and i am aware that my 89 sse has 3 coils and yes 1 and 4 share the same coil. So im a little confused by this. Is it bad wiring or just bad luck? I need some help please.
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Old 09-14-2007, 02:58 AM   #2
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do you hear the pump turn on when you switch the ignition? also do you have any way to test fuel pressure? it kinda sounds like a coil to me especially if 4 and 2 are missing...
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Old 09-14-2007, 09:39 AM   #3
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make sure all of your grounds are clean and replace the coil pack. if you really think its your fuel pump then open your hood and on the passenger side there should be a wire hangin by the horn give that wire positive off the battery and if you here it your good if not then make sure your grounds are clean and doit again
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Old 09-14-2007, 04:29 PM   #4
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Do you have a multi meter you could test the resistance of coils.
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Old 09-14-2007, 05:56 PM   #5
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What speed were you going when the RPMs would drop and jump. if you were going about 25mph, thats a normal characteristic of these cars and can be ruled out of the equation.
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Old 09-15-2007, 03:44 AM   #6
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Well I replaced the coil and guess what, nothing changed, the fuel pump does work i put a fuel pressure gauge on it and it runs fine, so now i am concerned to believe that it might be the pick up coil. I need to know where on the motor this i located cause i dont have a way of testing. I know that it is either in one of the cams or on the crank but im not sure, can anyone provide an answer for that
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Old 09-15-2007, 10:42 AM   #7
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Your car doesn't have a pickup coil. It does have a crank sensor just behind the balancer toward the front of the car. A failed sensor will not effect just two cylinders but all of them.
Are you sure just the two are not firing?
If #1 & 4 are not firing check for bad wires. you could also check for spark at the coil connection for these cylinders.
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Old 09-16-2007, 11:38 PM   #8
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Right, as stated above, if your crank sensor is bad, you have no spark at all.

Assuming that you really do have spark everywhere but the 1/4 coil then I would say swap that coil with another, see if the problem moves. If it does, the coil IS bad. If it doesn't, I'm thinking bad ICM.

Of course, that'* assuming that you have the individual Delco coils. If you've got the single Magnavox unit, then you'd just want to either swap in a new coil/ICM assembly, or better yet, upgrade to the Delco system. No better time.

Pretty much though, if you're getting spark on some wires and not others, I think the problem HAS to be either the ICM or coil(*). Someone correct me if I'm wrong, but I can't think of any other scenario.
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Old 09-17-2007, 12:34 PM   #9
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Thats right, you need to zero in on the coils first. Check accross the two terminals of each coil within the pack. If one has a higher ohm reading than the rest, it is bad.
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Old 09-18-2007, 02:51 AM   #10
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well i finally just took it into the shop and it was the ignitor located under the coil pack, and i took the advice from above and went ahead with the delco coil pack and i have to say i am impressed for how much it costed
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