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Just bought the car knowing it wasn't currently running . Charged the battery. It fires up but runs very rough like it's misfiring. Will barely idle and rpms will go up very very slowly pressing the gas like it's laboring.
-I tested the ignitor coils and both passed a bench test.
-I haven't tested the ignition coils yet but have read they rarely fail.
-new plugs/cap/rotor and NGK wires
-fuel pump is wired to a toggle switch
When I first got it started it seemed to be running on both rotors but idled like a bridgeport. I went through first and second gear down the road and then the misfiring and bucking started.
There is a massive hole in the muffler but I don't think that's the issue. Any ideas from the GSL-SE masters?
All in cockpit fuses are good and the fusible links seem intact as well
Of those 3 things you have mentioned I can only see the TPS possibly causing that issue as it's fuel injected. I'll check it with my multimeter tonight
You don't set the TPS with a multimeter, unless you're using 2 of them. A better tool is two light bulbs with flat spade connectors wired according to the FSM. It's quite possible the TPS isn't set correctly, which would lead to weird idle behavior, but off throttle and WOT, it should run fine. Once you get that set properly, take a look at;
1) Fuel Filter - has it ever been changed? Its specific to the SE and is a high pressure filter, so be sure to replace with OEM.
2) Air Flow Meter - check the air filter while you're there, but take a chopstick and run it in the intake door to test for smooth function.
3) Exhaust - if you're still running the catalytic converters, a collapsed cat will prevent revving properly. Removal of the cats and checking for a blocked core will help with diagnosis.
4) Ignition - take a close look at the cap and rotor to be sure it looks correct and is undamaged. Wipe it down thoroughly to remove any carbon tracking on the inside and outside, and push on the carbon button to be sure it springs back easily. If in doubt, replace them both as a set.
5) Spark Plugs - pull them and look at condition to see if it's flooding.
6) Injectors - with the engine running, grab the wiring harness at the base of the alternator and push, pull, tug, etc. and you'relistening for changes in the idle. If it changes, the wiring, connectors, or sockets on the injectors are corroded or shorting and will need to be fixed. Injectors are model-specific and NLA, so if an injector is bad, you'll want to get yours serviced.
7) Throttle Body Sticking - search on my username and "SE Surging" for the full rundown, but lubing the throttle rods will free them up to move properly.
Give these a shot and report back with what you find, also - why is your fuel pump wired to a toggle switch? That could be a serious safety issue, and contribute to this issue,
You don't set the TPS with a multimeter, unless you're using 2 of them. A better tool is two light bulbs with flat spade connectors wired according to the FSM. It's quite possible the TPS isn't set correctly, which would lead to weird idle behavior, but off throttle and WOT, it should run fine. Once you get that set properly, take a look at;
1) Fuel Filter - has it ever been changed? Its specific to the SE and is a high pressure filter, so be sure to replace with OEM.
2) Air Flow Meter - check the air filter while you're there, but take a chopstick and run it in the intake door to test for smooth function.
3) Exhaust - if you're still running the catalytic converters, a collapsed cat will prevent revving properly. Removal of the cats and checking for a blocked core will help with diagnosis.
4) Ignition - take a close look at the cap and rotor to be sure it looks correct and is undamaged. Wipe it down thoroughly to remove any carbon tracking on the inside and outside, and push on the carbon button to be sure it springs back easily. If in doubt, replace them both as a set.
5) Spark Plugs - pull them and look at condition to see if it's flooding.
6) Injectors - with the engine running, grab the wiring harness at the base of the alternator and push, pull, tug, etc. and you'relistening for changes in the idle. If it changes, the wiring, connectors, or sockets on the injectors are corroded or shorting and will need to be fixed. Injectors are model-specific and NLA, so if an injector is bad, you'll want to get yours serviced.
7) Throttle Body Sticking - search on my username and "SE Surging" for the full rundown, but lubing the throttle rods will free them up to move properly.
Give these a shot and report back with what you find, also - why is your fuel pump wired to a toggle switch? That could be a serious safety issue, and contribute to this issue,
I will check all those this weekend and report back! Thank you for the suggestions LongDuck!
The fuel pump is wired to a toggle switch by the previous owner. It was done to clear floods so I'm told and also because the fuel pump wasn't turning on. Now that I think about it, why wouldn't the fuel pump be turning on to begin with. I have gone through and replaced all of the fuses and as far as I'm aware nothing is burnt out or fried as everything else works.
It's not unusual for an SE to flood occasionally, so many owners installed a Fuel Pump cut switch into the under dash fuse block wired to a switch. This switch just impedes current flowing to the Fuel Pump circuit, which effectively cuts fuel so you can crank the engine at will to clear a flood. With the switch engaged (*for driving), with the engine off but key on, but not to Start - all of your idiot lights should be on. When you flip the switch, do any of the lights change?
With the switch off - Fuel Cut operation, with the engine off and key on, If only the outter 2 idiot lights are lit, and your parking brake is set, this is a good indicator to see how that switch is wired, as it could be an injectors cut switch, instead.
Without knowing what it's tied into, it's a guess if it even works. I suppose you could drive the car, coast into your driveway and flip the switch. If the engine immediately dies, you may be onto it. Otherwise, it may be an Injector Cut switch which impedes the signal from the Trailing Coil to the ECU (*white wire), and is preventing the ECU from firing the injectors - which performs the same function, but doesn't cut power to the Fuel Pump.
Either way, I'd want to know how it's wired up for future troubleshooting,
So i followed the wiring and I will be removing this and putting the wiring back to factory and going from there, i feel like this is unsafe and will burn out the switch/wires.
I found out there is a wire running from the fuel pump along the bottom of the vehicle up into the engine bay and into the firewall to the toggle switch. Then there is another wire from the battery , 12V hot going to the switch, and then a ground wire from the engine bay through the firewall to the switch.
Im going to have to redo the wiring for this and just use a cut switch instead like you suggested. Thank you for your help/suggestion. Yes it currently works but holy hell is this unsafe lol. There is not even a fuel inline at all.....
Also, when you can turn the fuel pump on/off without even having the key in the ignition. Wowzers!
Before you rip it all out for safety sake, recognize that the PO wired it that way for a reason. You may find that with your power line removed, the Fuel Pump may not be getting power through the factory wiring setup. If that's the case, you may have a considerable task ahead of you to find the source of the problem and fix it.
The SE uses a somewhat complicated method to ensure that fuel doesn't flow when it shouldn't via a Circuit Opening Relay located on the frame for the ECU under the passenger footwell. This Circuit Opening Relay opens the circuit (*heh) to the Fuel Pump in the event that a signal is not passed through several grounds available to the system and tied to the ignition. I had a period of several months trying to track down a bad ground at the starter and a short at the Bypass Air Control Valve solenoid that looked and acted like a bad Circuit Opening Relay or associated wiring. Not to confuse the situation, but you might benefit from looking at this;
Fortunately I talked to my buddy about it and found that the wiring was actually just tapped into the wiring in the storage box behind the seat. I found it in there and it's just a matter of unplugging the connectors he added and reconnecting the old wiring. All of the factory wiring is still there thank the rotary gods. Once that's done I will be able to sort out why the fuel pump wasn't working originally.
How uncommon is it for an ignitor to test good but actually be bad? He said he couldn't get it started even with the fuel pump on wired the way he has it yet I just swapped the ignitors around and it fired for me after cranking for 5 seconds. I originally swapped the ignitors because I had read the trailing ignitor gives signal to the fuel pump/injectors and when I fired I figured I the other ignitor was pooched. After testing with the wired bench test they seem to be in working condition.
Also, in the future you can test the Ignitor by switching just the white lead for the ECU trigger (for injector pulse timing) from the Trailing Coil to the Leading Coil. This will trigger the ECU to fire the injectors, but slightly out of time. It will still start and run, though - and will prove the Ignitors are both working. I've done this as a quick fix to get back on the road after my Trailing Ignitor died suddenly, and when your Trailing Ignitor dies in an SE - you're dead in the water unless you swap the white lead because the ECU isn't getting the trigger to fire the Injectors...
Also, in the future you can test the Ignitor by switching just the white lead for the ECU trigger (for injector pulse timing) from the Trailing Coil to the Leading Coil. This will trigger the ECU to fire the injectors, but slightly out of time. It will still start and run, though - and will prove the Ignitors are both working. I've done this as a quick fix to get back on the road after my Trailing Ignitor died suddenly, and when your Trailing Ignitor dies in an SE - you're dead in the water unless you swap the white lead because the ECU isn't getting the trigger to fire the Injectors...
Ahh. I swapped the ignitors themselves and kept the wiring the same. Got it to fire that way but runs rough like its only on one rotor
Did you deduce that you need another Ignitor? Search on J-109 as those are the ones used in our cars. If the engine now starts and runs, but not correctly, it's possible you're only running on Trailing Ignition, which the car will do, but not happily. Leading Ignition alone runs and idles well, as Trailing is there for fuller combustion and to reduce emissions.
Did you deduce that you need another Ignitor? Search on J-109 as those are the ones used in our cars. If the engine now starts and runs, but not correctly, it's possible you're only running on Trailing Ignition, which the car will do, but not happily. Leading Ignition alone runs and idles well, as Trailing is there for fuller combustion and to reduce emissions.
The two that are on the car right now I removed and bench tested. They tested out fine. I have another used ignitor I bought which also tests fine. I'm wondering though can they test fine but also be faulty. The reason I ask is because it runs rough from the get go, they don't even have time to heat up so it kind of rules out that they fail when they get hot.
The way they mount could have a lot to do with them testing correctly on the bench, but not in the car. Pay particular attention to the mounting surfaces and the wiring harness carrying the current and the connectors. You could have an intermittent short which causes problems on the car.
10-20-20, 11:29 PM
