Engine Runs Rough
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Member
Joined: Mar 2001
Posts: 53
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From: Atlanta, Georgia, USA
Steve -
#1 Have to check again to see how the color of the wires on the E3TB, 9345, A2A relay we found compare to those in the article. Did buy a "fuel pump relay" at AutoZone which looks similar to our E3TB, 9345, A2A but the AutoZone relay has five blades where our E3TB, 9345, A2A has four blades. There is a fifth slot (presently unused) in the harness connector but we elected not to try the five-blade afternarket relay particularly since we are not sure if the E3TB, 9345, A2A is indeed the fuel pump relay. Did search under the seat and under the dash for the fuel pump relay but did not find anything.
#2 Yes. Back-probing the black wire and green wire on the harness side of the new TPS with the key on, we got a reading of .998 volts with the throttle closed and 4.66 with the throttle wide open. Though Haynes says you can then test the resistance of the Potentiometer in the TPS by disconncting the TPS and probing the same two wires (black wire and green wire), we were unable to get a reading in the range specified by Haynes. By switching to the orange wire and green wire, we got a reading of 3.20 K ohms with throttle closed and 687 ohms with throttle wide open - these values are somewhat near the Haynes' specs.
#3 Did the fuel pressure test (forgot to jumper the DLC) but was able to hear the rear in-tank fuel pummp running; was not able to hear the front in-tank fuel pump running. This was as-expected as the truck will run off the rear tank but not off the front tank. Did not try disconnecting the fuel line and allowing gas to be pumped out due to concerns about fire hazard.
#4 Started the truck and it exhibits the same "coughing and sputtering when cold" symptoms as before. As it warmed up, I was able to hold the accelerator steady at about 1100 rpms. The engine would drop to about 650 rpms then rev to about 2000 rpms, drop back to about 1100 rpms, then drop to 650, rev to 2000, drop to 1100, etc., etc. This cycle diminished as the engine warmed further until it would simply idle at about 650 rpms with no revving. However, it does hesitate and lurch if I engage the transmission and accelerate.
Thank you.
Tom
#1 Have to check again to see how the color of the wires on the E3TB, 9345, A2A relay we found compare to those in the article. Did buy a "fuel pump relay" at AutoZone which looks similar to our E3TB, 9345, A2A but the AutoZone relay has five blades where our E3TB, 9345, A2A has four blades. There is a fifth slot (presently unused) in the harness connector but we elected not to try the five-blade afternarket relay particularly since we are not sure if the E3TB, 9345, A2A is indeed the fuel pump relay. Did search under the seat and under the dash for the fuel pump relay but did not find anything.
#2 Yes. Back-probing the black wire and green wire on the harness side of the new TPS with the key on, we got a reading of .998 volts with the throttle closed and 4.66 with the throttle wide open. Though Haynes says you can then test the resistance of the Potentiometer in the TPS by disconncting the TPS and probing the same two wires (black wire and green wire), we were unable to get a reading in the range specified by Haynes. By switching to the orange wire and green wire, we got a reading of 3.20 K ohms with throttle closed and 687 ohms with throttle wide open - these values are somewhat near the Haynes' specs.
#3 Did the fuel pressure test (forgot to jumper the DLC) but was able to hear the rear in-tank fuel pummp running; was not able to hear the front in-tank fuel pump running. This was as-expected as the truck will run off the rear tank but not off the front tank. Did not try disconnecting the fuel line and allowing gas to be pumped out due to concerns about fire hazard.
#4 Started the truck and it exhibits the same "coughing and sputtering when cold" symptoms as before. As it warmed up, I was able to hold the accelerator steady at about 1100 rpms. The engine would drop to about 650 rpms then rev to about 2000 rpms, drop back to about 1100 rpms, then drop to 650, rev to 2000, drop to 1100, etc., etc. This cycle diminished as the engine warmed further until it would simply idle at about 650 rpms with no revving. However, it does hesitate and lurch if I engage the transmission and accelerate.
Thank you.
Tom
Thread Starter
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Member
Joined: Mar 2001
Posts: 53
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From: Atlanta, Georgia, USA
Steve - Tried to post a photo to this forum of the fuel pump (?) relay we found. See 
The black plastic shroud that covers this relay mounts to the firewall immediately to the right of my thumb knuckle in the photo.
Does this help identify it as the fuel pump relay?
Thanks,
Tom
The black plastic shroud that covers this relay mounts to the firewall immediately to the right of my thumb knuckle in the photo.
Does this help identify it as the fuel pump relay?
Thanks,
Tom
Senior Member
Joined: Nov 2006
Posts: 5,495
Likes: 7
From: Memphis, TN 38135, USA, Earth
Once you've uploaded a pic, right-click it, then click Properties, then triple-click the URL to select it all. Hit Ctrl+C to copy it, close that window, then click the yellow image icon above the text box, hit Ctrl+V to paste it, & Enter to drop it into your reply, like this:
1) I wouldn't buy a dirty rag in the zone, even if I needed one. Yes, that looks just like the one in my photos, but you have to check the wire colors to be sure that it's the FP relay. The EEC PWR relay should be nearby.
2) Did the reading change smoothly & evenly as you opened the throttle?
3) What pressure did you get?
4) Test the ECT, ACT (IAT), & ignition system. Haynes shows how.
1) I wouldn't buy a dirty rag in the zone, even if I needed one. Yes, that looks just like the one in my photos, but you have to check the wire colors to be sure that it's the FP relay. The EEC PWR relay should be nearby.
2) Did the reading change smoothly & evenly as you opened the throttle?
3) What pressure did you get?
4) Test the ECT, ACT (IAT), & ignition system. Haynes shows how.