turner
Well-Known Member
- Joined
- Jul 21, 2021
- Messages
- 47
- City
- Santa Cruz, CA
- Vehicle Year
- 1987
- Engine
- 2.3 (4 Cylinder)
- Transmission
- Manual
This one has me puzzled. 1987 2.3L. The pattern is perfectly consistent, I took video that starts with the truck running (from cold), and goes through the symtoms below.
https://youtube.com/shorts/2mB6WbhteIA?feature=share
Symptoms:
I have the factory manual + emissions/diagnostic manual, so I've gone through their troubleshooting procedures. Here's what I've tried:
Because of the way the engine shut off while driving, I figured it HAD to be spark. But the way the engine surges then dies after sitting, made me think maybe the fuel pump isn't working when hot, and the engine is using it's last gulp. The consistency is what's puzzling me. If the electrics aren't sending a spark on restart, how does that surge happen? And so consistently? Always the exact same amount of time from start to surge to shutoff.
To do:
Does this ring any bells for the experts here?
https://youtube.com/shorts/2mB6WbhteIA?feature=share
Symptoms:
- Runs perfectly from cold, drives for any length of time or distance, no issues.
- (After parking and turning off) Trying to restart-- will fire right away, surge to 2000 rpm, then shut itself off immediately
- After that single surge, it won't fire at all for some period of time (5min, 30min, 6 hours)
- This week while driving, it also shut off while on throttle moving down the road. No sputtering or coughing, just immediately stopped firing like flipping a switch.
I have the factory manual + emissions/diagnostic manual, so I've gone through their troubleshooting procedures. Here's what I've tried:
- Replaced (original) fuel pump relay because the contacts looked a little melty.
- Back-probed TFI connector to make sure it gets 12V on the right wires at the right times, using this site's guide. Checked out good
- Replaced TFI module
- Coil measured good, spark is good, plugs are good (new), wires are good (6 mo old), battery is good
- Bypassed cutout switches for good measure (inertia + clutch switches)
- Ignition switch is 6mo old
- Pulled distributor, replaced pickup coil + drive gear. Cap + rotor are 6mo old.
- No obvious loom issues/grounds
- Only code is TPS voltage out of range, which is always the case (unless I've recently adjusted it)
- After the symptoms have started (won't restart), there is no spark at the coil wire while cranking (haven't rechecked this since overhauling dizzy)
Because of the way the engine shut off while driving, I figured it HAD to be spark. But the way the engine surges then dies after sitting, made me think maybe the fuel pump isn't working when hot, and the engine is using it's last gulp. The consistency is what's puzzling me. If the electrics aren't sending a spark on restart, how does that surge happen? And so consistently? Always the exact same amount of time from start to surge to shutoff.
To do:
- Test for spark while symptoms are active (again, since I've rebuilt dizzy/TFI)
- Check fuel pressure while symptoms are active
Does this ring any bells for the experts here?