official rough idle/surge/misfire

[Timpala]

Wow, you might have just diagnosed my problem.
I also replaced my fuel pump with a device that looked correct. I've had weird problems on the the highway with the engine running very warm even though I'm on a electric water pump.

If my fuel level is low and I take a hard turn it acts like it's fuel starving and will almost quit. But doesn't do that with a full tank.

Looks like I'll be picking up a fuel pressure gauge today. Thanks!

[ajharman]

Originally Posted by Timpala

Wow, you might have just diagnosed my problem.
I also replaced my fuel pump with a device that looked correct. I've had weird problems on the the highway with the engine running very warm even though I'm on a electric water pump.

If my fuel level is low and I take a hard turn it acts like it's fuel starving and will almost quit. But doesn't do that with a full tank.

Looks like I'll be picking up a fuel pressure gauge today. Thanks!

Hope you get it figured out man. I know how frustrating trying to track it down is. I'm definitely glad I bought the pressure tester. Advance doesn't rent them, and I'm sure it will come in handy a couple more times in the future.

I bought this one for $33 on Amazon:

Actron CP7818 Fuel Pressure Tester Kit : Amazon.com : Automotive

Actron CP7818 Fuel Pressure Tester Kit : Amazon.com : Automotive

It's made by Actron and is the cheapest one I could find that looked decent. It suits my needs fine as just a simple unit, has worked well so far and has the pressure release hose so you can catch fuel in a container when disconnecting it. It includes threads for both GM and Ford fuel rails. They sell a model with TBI and import adapters too for like $10 bucks more, I just didn't think I'd need all that.

[Timpala]

O'Reilly in town had a gauge that I could use for a few minutes. Sure as heck, 10lbs of pressure. Must be running lean as can be as it's hotter than normal all the time. Now what are all the cool kids running for replacement fuel pumps?

[ajharman]

Originally Posted by Timpala

O'Reilly in town had a gauge that I could use for a few minutes. Sure as heck, 10lbs of pressure. Must be running lean as can be as it's hotter than normal all the time. Now what are all the cool kids running for replacement fuel pumps?

I'm not sure what mods you have or what your fuel demand is, but if all you need is a stock spec OEM pump, the Delphi FE0114 is a good option. That's the one I just dropped in mine a month ago and its doing fine. Rockauto carries it for pretty cheap ($60-70), I got mine through a local NAPA though so it was more expensive.

[GradybabyJ]

Originally Posted by POPIMPIN CUSTOMS I.N.C.

for those that do not know, the spark plug wires ALL have to click twice into the opti or they are not seated properly

im ashamed to say i didn't know that but i've never left it loose though.

[GregC]

Mine had that hesitation when accelerating from a stop, then it would also feel like it was going to die like it was running out of gas when cruising. I replaced the ICM, which fixed the hesitation and the running out of gas like symptom. But it left me stranded again and the car wouldn't start. I waited 5 minutes and the car started. I just replaced the coil, so hopefully that fixed the problem. But I'm betting it's the Opti that needs replacement. The previous owner had used parts that were low budget non oem.

[chevyrida79]

Originally Posted by GregC

Mine had that hesitation when accelerating from a stop, then it would also feel like it was going to die like it was running out of gas when cruising. I replaced the ICM, which fixed the hesitation and the running out of gas like symptom. But it left me stranded again and the car wouldn't start. I waited 5 minutes and the car started. I just replaced the coil, so hopefully that fixed the problem. But I'm betting it's the Opti that needs replacement. The previous owner had used parts that were low budget non oem.

Can you please help me out and explain what the ICM is please. Im having the exact same problem and I dont want to assume anything.
Nevermind I got it!!lol

[GregC]

Originally Posted by chevyrida79

Can you please help me out and explain what the ICM is please. Im having the exact same problem and I dont want to assume anything.

The ICM is the ignition control module, but if you are going to replace the ICM, you might as well replace the coil too since they are co-located. The ICM and coil are located in front of the driver's side head. It is the module on top. The one below it is the coil. To access it without busting your knuckles, remove the home base plate and get the air intake house out of the way. Then you'll have to unplug the connectors on the ICM and Coil and coil wire. Undo the 2 bolts holding the bracket that holds both modules and pull out both modules. You'll have to use a very small socket to remove the ICM and the Coil from the bracket. Reinstall in reverse order. Make sure you buy AC/Delco or Delphi or you might be replacing it again. So far so good. No problems after 3 weeks. The next thing I'll replace is the Opti before it goes bad.

[ajharman]

Originally Posted by chevyrida79

Can you please help me out and explain what the ICM is please. Im having the exact same problem and I dont want to assume anything.
Nevermind I got it!!lol

Ignition control module. Mounted above the coil by those aluminum fins.

http://shbox.com/1/coil_loc.jpg

[chevyrida79]

Thanks alot!!! My 94 SS just started this misfire/stumble behavior under light throttle and under heady WOT it acts like its running on 7 cylinders. Its pissing me off!!!! No CEL no codes??? Just started right after letting my friend take his wife out in it....smh