alp
New Member
- Joined
- May 30, 2019
- Messages
- 5
- Reaction score
- 0
- Points
- 1
- Location
- Massachusettes
- Vehicle Year
- 1988
- Make / Model
- Ford Ranger
- Engine Type
- 2.9 V6
- Transmission
- Automatic
- 2WD / 4WD
- 2WD
Hello! I've owned a 1988 Ranger XLT RWD 2.9L Automatic for about a year and a half now, it's always had a tiny bit of a shake at idle, but after one incident a couple months ago I've had no luck solving this issue. What happened was, I was driving to a shop that my friend worked at after hours to check out some underbody stuff on the lift, and on the way there the truck died on the highway, lost spark. I didn't have AAA at the time (I sure as hell do now) and my friend's boss would only let him tow me in if I agreed to let their techs work on it (he was an oil/tire/alignment guy, no heavy diag stuff) and their guy diagnosed it as a bad ignition module AND distributor.
They changed that, which didn't work, but told me that the parts they got were bad, and they had to put on another dizzy/TFI module. After that, on initial startup the truck would sputter heavily, rocking the whole truck back and forth for about 15-30 seconds before getting it's shit together. They brushed it off saying 'it just needs a tune up', well it had a brand new dizzy(including cap & rotor) so I did the plugs & wires to no avail. (Incidentally, the truck also stopped shifting into O/D and wasn't locking the torque converter clutch, but turns out they just managed to unplug the transmission somehow ) First and last time at a shop for me..
The sputter is much worse in cold weather or humid weather, and strangely is also much worse when any other relatively high amp draw accessory is used (head lights, reverse lights, especially blower motor) (Video showcasing issue) Can take up to 10 minutes or more to stop sputtering when cold out or humid. The tach also seems to jump from around 1000 to 800 on the way down, as shown in the video at the end, but I'm unsure if that was happening before, or if it's normal. After warming up the truck seems to run fine, other than a slight shake at idle (even after new plugs & wires)
Things I've checked:
I'm sorry to have such a long winded post as my first post, but I heavily appreciate anyone who's even read the majority of this. With winter coming up and needing to make it to school, I'm worried about this issue and I'm a bit stumped at this point, don't have the cash to just be throwing parts at it. Anyone who has any suggestions or ideas would mean the world to me.
Thanks in advance to the good people of this forum
-Alex
They changed that, which didn't work, but told me that the parts they got were bad, and they had to put on another dizzy/TFI module. After that, on initial startup the truck would sputter heavily, rocking the whole truck back and forth for about 15-30 seconds before getting it's shit together. They brushed it off saying 'it just needs a tune up', well it had a brand new dizzy(including cap & rotor) so I did the plugs & wires to no avail. (Incidentally, the truck also stopped shifting into O/D and wasn't locking the torque converter clutch, but turns out they just managed to unplug the transmission somehow ) First and last time at a shop for me..
The sputter is much worse in cold weather or humid weather, and strangely is also much worse when any other relatively high amp draw accessory is used (head lights, reverse lights, especially blower motor) (Video showcasing issue) Can take up to 10 minutes or more to stop sputtering when cold out or humid. The tach also seems to jump from around 1000 to 800 on the way down, as shown in the video at the end, but I'm unsure if that was happening before, or if it's normal. After warming up the truck seems to run fine, other than a slight shake at idle (even after new plugs & wires)
Things I've checked:
- Paint mark the shop tech put on pulley for cyl 1 TDC & 10deg BTDC seem to be accurate (base timing is good if so)
- Computer is able to control timing (and KOER test has the #1 plug firing right around 30deg BTDC as docs say it should)
- Voltage drops from Battery + to the ignition coil positive check out, as well as the ground of the condenser to the the battery - terminal (Hard to check the VD of the coil's primary ground, as it's pulsed while running, but seems to be down one volt, but for all I know the TFI module could be consuming that 1 volt as normal operation)
- Charging system voltage seems good, as well as charging system voltage drops & diodes (23mV of AC at battery)
- Before new dizzy was put on, checked the condenser's operation and seemed to work fine
- Ignition coil's primary measured around 1Ω, and 8kΩ on secondary, in spec but I've read that doesn't necessarily mean it's A-OK
- Vacuum seems OK (I show my gauge in the video above, but I'm not an expert tech by any means, especially on passenger vehicles, currently schooling to be a heavy duty diesel tech)
- When the sputtering happens, the plug either isn't firing or is firing WAY too soon (I didn't see a flash from my timing light, but was a little bright out so possibly the white paint of the timing mark was way farther ahead than it should've been)
- The sputtering SEEMS to stop when the SPOUT jumper is unplugged, but need the engine to keep it's bullshit up for a little bit to really test that for sure
- Fuel rail pressure (I don't have a gauge to check that, and am a bit strapped for cash. I probably would've been throwing parts at this willy nilly already if I had the money)
- Voltage drops between main computer & TFI module
- I noticed that the tech put a butt connector on the coil negative wire (pin #2) right at the TFI module connector
- TFI pin #4 (Start signal) should recieve 12v while cranking correct? Doesn't seem to.
- The truck has had code 18 but no other codes stored in memory twice now, but I believe that could be set from having the SPOUT jumper unplugged while running to check base timing. Currently no other codes in the KOEO, CM, or KOER test.
- Electrical issues seem most likely judging by the symptoms. Possible suspects:
- Battery
- Wiring (Grounds or otherwise)
- Ignition timing
- Ignition coil
- EEC Computer
- The new TFI Module or Distributor
- I have a BOB, but no sadly no scope so can't do too much advanced diag/logging
- I feel like the most important thing to note about this direction, is how the issue becomes worse as accessories such as the blower motor are turned on.
- Air intake
- A new air filter wouldn't hurt, but doubt it would solve my issue
- The fancy air box that huffs hot air from around the exhaust manifold while the engine is cold, could that be clogged choking the engine out while cold? Doesn't seem likely.
- Fuel
- Injectors, wiring, filter, pump or otherwise.
- Is evap a possibility?
I'm sorry to have such a long winded post as my first post, but I heavily appreciate anyone who's even read the majority of this. With winter coming up and needing to make it to school, I'm worried about this issue and I'm a bit stumped at this point, don't have the cash to just be throwing parts at it. Anyone who has any suggestions or ideas would mean the world to me.
Thanks in advance to the good people of this forum
-Alex