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#60222 05/06/02 05:12 PM
Joined: May 2000
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fst4dr Offline OP
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For the past two months I have had this problem and it has just gotten really bad. At first my car would just hesitate a little over the occasional bump. It would not stall completely just act as if someone turned the ignition off for a fraction of a second. It only happened over bumps. I figured it was a loose wire somewhere, but could not solve it. This last weekend it happened again but did not return to normal.

It will not idle for very long. It will just about die then catch itself and about die again. It will do this for awhile until it does stall. I can feather the throttle and get it up to about 2000 rpm and it will run fine, but that is just in neutral with no load. As soon as I rev it a little harder it will start missing again.

It also Idles extremely rough at anything under 2000 rpms. I think it is either a fuel delivery problem, or an ignition problem.

If the fuel filter is clogged will my fuel pressure gauge still read normal. Nothing seems peculiar about the FP so I think everything is good to go with that.

I had to relocate the battery to the trunk,so there is a bundle of wires under the hood. My other idea was that one of these wires that ran to the battery, supplied power to the coil pack. Is this true? Maybe that wire has a loose connection.

I forgot to hook up my MAF once and it ran sort of the same way, but the Maf is hhoked up and I have checked all the wires going to it and they all seem fine. I checked all the fuses and have reset the Vortech chip a few times. Nothing seems to help.

Any Ideas?

I guess I could change the fuel filter, as that would probably be the cheapest place to start.


Speed kills, but it beats going slow!

Simon Langley
Black 98 SVT EO (#2119 of 6535)
269.3 FWHP, 195.4 TQ
14.123 @ 97.36
All go, and no show!
Vortech, Quaife, Driveshaft Shop Stage II axles, Magnecore Wires, Custom True Dual Exhaust.
CDW-27 1/4 Mile Registry
Joined: Jun 2001
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What you are describing sounds like a classic loose or failing electrical connection.

I'd check out the wires going to components on the engine like the MAF, IAC, O2s, ignition module, battery and the spark plug wires etc. As you check the connections pull the plugs appart and look at the pins and sockets, its possible that a one has broken or there's corrosion.

If you have access to one hook up a code scanner and see if the computer has any codes, since they might point you to the problem.


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fst4dr Offline OP
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Update:

Went out this morning and checked everything. I took all the vortech stuff under the hood out except the blower. I checked my connections for the battery relocation and checked that all the grounds were clean. Then I reinstalled all the vortech stuff and wire tied everything neatly to make sure nothing was flopping around. (it was a mess before :rolleyes: )

It is a little bit better. I can drive it now, but it still wont hold an idle. I took it for a test spin and it stumbles and struggles up to about 5000 and then it takes off like there is no problem. I did this a few times, and then realized that my air/fuel gauge was reading full lean...almost off the scale eek when it was struggling. Then the point were it takes off like normal the gauge would go to full rich.

I realized that the "fix" at 5000 was when the FMU really starts bumping up the fuel pressure under boost.

So I guess this is turned into a fuel delivery problem. Why does it run so lean at idle and low RPM conditions? I should add that the vortech should not have any effect on the fuel delivery since it only starts building boost at about 3000 and that is when the FMU starts bumping up the fuel pressure. I am hoping to be able to diagnose this as a N/A problem.

Any Ideas?


Speed kills, but it beats going slow!

Simon Langley
Black 98 SVT EO (#2119 of 6535)
269.3 FWHP, 195.4 TQ
14.123 @ 97.36
All go, and no show!
Vortech, Quaife, Driveshaft Shop Stage II axles, Magnecore Wires, Custom True Dual Exhaust.
CDW-27 1/4 Mile Registry

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