gcaiola
New Member
- Joined
- Nov 16, 2009
- Messages
- 9
- Reaction score
- 0
- Points
- 1
- Location
- Raleigh, NC
- Vehicle Year
- 1994
- Make / Model
- Ford
- Engine Size
- 2.3L
- Transmission
- Manual
Suddenly began running rough on drive home from work, but while i was idling, talking to a neighbor. Idles poorly but does not stall or backfire. Starts consistently but accelerates so poorly it can’t be driven safely.
I popped the hood and noticed a vacuum hose that should connect to EVAP canister was completely off due to rubber boot dry-rotting. I have no idea how long it may have been disconnected. It’s a pre-formed black plastic tube, with custom bends, that connects evap canister to somewhere under throttle body, on firewall side. I can’t see it’s connection on the throttle end but it “seems” to be secured on the throttle body end, when I give it a light tug.
More details:
- A mechanical knocking or vibrating sound seems to come from underside of engine—or at least that’s where I hear it.
- Liquid drips from exhaust pipe –seems to be water
- After it idles for a few minutes (or less), when I turn it off, I can hear “fast dripping” sound in/near engine area for the next 15-30 seconds—like liquid is dripping somewhere. But nothing is dripping on the ground—so that is internal to something. (or maybe that sound has always been there and I never noticed)
- I have never changed vacuum hoses on this car. So it’s possible the rubber hoses are due to break down soon—although most look pretty good.
What I have done:
- No check engine light or diag codes come up
- Reinstalled air hose back in place on the evap canister side. Note I did not do a thorough check on this tube at other end, because I can’t see back below the throttle body where connects. I probably need to give this more attention but have been distracted due to other things below.
- Put a timing light on each plug wire, right off the coils. I did not check actual timing, just watched light pulses to check for anything unusual. The coilpack near front of car triggers light on/off consistently--checked all 4 wires. The coilpack behind it (nearest firewall) seems to pulse much quicker and slightly erratic. Along with that it seems the timing light pulses more dimly from all 4 of those wires (passenger side plugs of engine block), and I can see the light off (“missing”) occasionally. I tried to catch this on video but digital video loses some of this activity. Should the timing light look same for all plug wires, and on both coil packs?
- Removed all plug wires from both coil pack side, and checked resistance on both coils packs. Looks good across both pairs for each coil pack.
- I assumed that timing signals should be similar on both coil packs and since coil packs seemed ok, I replaced Ignition Module without doing a full diagnosis—hoping for an easy fix. Did not fix.
- Installed vacuum gauge. With engine idling, needle bounces VERY quickly between 14-17 inches. Read online this could be caused by stuck valve. But since this engine fires plugs on exhaust stroke also, I am guessing it could be any normal plug or plug wire problem on any 1 cylinder. Is that correct?
Between the vacuum reading and the funky timing light difference on rearmost coilpack (vs frontmost), I don’t know if I should be chasing a possible vacuum leak or an electrical issue that might be causing me to see the vacuum needle bounce. And because of the unusual timing light signal from the rearmost coil pack (on ALL its plug wire outputs), I assumed it could not be simply a single plug or wire. Am I over-complicating this?
I would appreciate any suggestions.
I popped the hood and noticed a vacuum hose that should connect to EVAP canister was completely off due to rubber boot dry-rotting. I have no idea how long it may have been disconnected. It’s a pre-formed black plastic tube, with custom bends, that connects evap canister to somewhere under throttle body, on firewall side. I can’t see it’s connection on the throttle end but it “seems” to be secured on the throttle body end, when I give it a light tug.
More details:
- A mechanical knocking or vibrating sound seems to come from underside of engine—or at least that’s where I hear it.
- Liquid drips from exhaust pipe –seems to be water
- After it idles for a few minutes (or less), when I turn it off, I can hear “fast dripping” sound in/near engine area for the next 15-30 seconds—like liquid is dripping somewhere. But nothing is dripping on the ground—so that is internal to something. (or maybe that sound has always been there and I never noticed)
- I have never changed vacuum hoses on this car. So it’s possible the rubber hoses are due to break down soon—although most look pretty good.
What I have done:
- No check engine light or diag codes come up
- Reinstalled air hose back in place on the evap canister side. Note I did not do a thorough check on this tube at other end, because I can’t see back below the throttle body where connects. I probably need to give this more attention but have been distracted due to other things below.
- Put a timing light on each plug wire, right off the coils. I did not check actual timing, just watched light pulses to check for anything unusual. The coilpack near front of car triggers light on/off consistently--checked all 4 wires. The coilpack behind it (nearest firewall) seems to pulse much quicker and slightly erratic. Along with that it seems the timing light pulses more dimly from all 4 of those wires (passenger side plugs of engine block), and I can see the light off (“missing”) occasionally. I tried to catch this on video but digital video loses some of this activity. Should the timing light look same for all plug wires, and on both coil packs?
- Removed all plug wires from both coil pack side, and checked resistance on both coils packs. Looks good across both pairs for each coil pack.
- I assumed that timing signals should be similar on both coil packs and since coil packs seemed ok, I replaced Ignition Module without doing a full diagnosis—hoping for an easy fix. Did not fix.
- Installed vacuum gauge. With engine idling, needle bounces VERY quickly between 14-17 inches. Read online this could be caused by stuck valve. But since this engine fires plugs on exhaust stroke also, I am guessing it could be any normal plug or plug wire problem on any 1 cylinder. Is that correct?
Between the vacuum reading and the funky timing light difference on rearmost coilpack (vs frontmost), I don’t know if I should be chasing a possible vacuum leak or an electrical issue that might be causing me to see the vacuum needle bounce. And because of the unusual timing light signal from the rearmost coil pack (on ALL its plug wire outputs), I assumed it could not be simply a single plug or wire. Am I over-complicating this?
I would appreciate any suggestions.