N/A Hesitation/Cutting out
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N/A Hesitation/Cutting out
I picked up a GSL-SE with an 86 N/A motor from a friend. The motor has 60k on it and my friend said it ran really strong before he swapped it into the GSL-SE. The car sat for 3-4 years and I'm here to finish everything up, so I can daily this beast. The car idles solid and under very light throttle seems to drive fine.
Whenever I give the car a little heavy throttle it will buck/sputter/cut out. I'm still trying to figure out why the tachometer doesn't work, so I have no idea what RPM this is happening at (assuming that it's happening at a certain RPM).
Even when the car isn't in gear and I rev it up with heavy throttle input it hesitates. It's not nearly as bad as when I'm actually driving the car though.
I took the LIM off and replaced the sleeves with Pineapple Racing sleeves and made sure the aux ports move smoothly, which they do now. I don't know if I should risk flooring it or anything to see if the aux ports are opening.
Any ideas on where to start diagnosing? I was thinking of tracing the wiring to the secondary injectors to see if they are kicking on..anything else?
Whenever I give the car a little heavy throttle it will buck/sputter/cut out. I'm still trying to figure out why the tachometer doesn't work, so I have no idea what RPM this is happening at (assuming that it's happening at a certain RPM).
Even when the car isn't in gear and I rev it up with heavy throttle input it hesitates. It's not nearly as bad as when I'm actually driving the car though.
I took the LIM off and replaced the sleeves with Pineapple Racing sleeves and made sure the aux ports move smoothly, which they do now. I don't know if I should risk flooring it or anything to see if the aux ports are opening.
Any ideas on where to start diagnosing? I was thinking of tracing the wiring to the secondary injectors to see if they are kicking on..anything else?
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A good start is always to pull the ECU Codes, regardless of the issue it will give you a good baseline as to whats going on.
If the tach doesnt work your issue could be ignition/ coil related. Are you sure the swap has been completed correctly? no missing grounds or loose connectors? Simple things can often make the difference
If the tach doesnt work your issue could be ignition/ coil related. Are you sure the swap has been completed correctly? no missing grounds or loose connectors? Simple things can often make the difference
#6
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A good start is always to pull the ECU Codes, regardless of the issue it will give you a good baseline as to whats going on.
If the tach doesnt work your issue could be ignition/ coil related. Are you sure the swap has been completed correctly? no missing grounds or loose connectors? Simple things can often make the difference
If the tach doesnt work your issue could be ignition/ coil related. Are you sure the swap has been completed correctly? no missing grounds or loose connectors? Simple things can often make the difference
What series engine was put in it?
When it comes to the tach, it gets it signal from the trailing coil, on FCs IIRC it is a yellow wire, if your trailing coil isn't fireing either could be your problem as well
Another issue, the car sat for 3 years, have you replaced the fuel filter? Dropped the tank and replaced the sock? When were the injectors last serviced? All these fuel related systems SHOULD be cleaned/replaced after sitting for over a year as gas turns sour after 3 months if not less
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Fuel tank was dropped, cleaned, etc. Fuel filter and sock have been replaced. I can see if pulling codes is an option. The car does have all the smog equipment in place and working. I don't want to, but if they end up being the issue I'll send the injectors out to be serviced.
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#8
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One way or the other, you can bet that it's tied to either the fuel system or the ignition system. Black box electrickery adds another layer, but you should be able to narrow it down to a few testable components simply according to what's at play/in flux when it misbehaves.
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One way or the other, you can bet that it's tied to either the fuel system or the ignition system. Black box electrickery adds another layer, but you should be able to narrow it down to a few testable components simply according to what's at play/in flux when it misbehaves.
Also OP, I DOUBT you'll be able to pull codes, your gonna have to diagnose this the old fashioned way
my steps would be:
1. Check the trailing coils to see if they are sparking, if not, check to make sure they are getting power and ground
2. Check the wiring, see if its hacked up, if not, look at the FSM to see what wire runs the tach
3. if 1 and 2 checks out, check for vacuum leaks (doubtful, but still a possibility)
4. Check ALL engine/computer grounds
5. if 1-4 check out, make sure the injectors are getting signal to fire, and make sure they are spraying fuel
6. if all the above are good, then send the injectors out for service
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Better video of me free revving it. At 4k it hits a brick wall unless I ease into the throttle and even then it breaks up around 5k. I already spliced in extra grounds for the ecu, so I don't think it's a grounding issue anymore. I'm sending the injectors out to be cleaned/flow tested to rule that out..still looking for ideas.
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P/O said he put a new one on when he dropped the gas tank. I'll replace it for the heck of it I suppose since I'm going to have down time while the injectors are off being serviced. I think I may try to trace the wires from the ECU to the secondary injectors to see if the circuit is unbroken.
#16
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Sounds like a very bad3800 hesitation.
Check all your grounds first, making sure their nice and clean and tight. Emphasis on the ECU to engine, then engine to battery
Check all your grounds first, making sure their nice and clean and tight. Emphasis on the ECU to engine, then engine to battery
#17
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come on Nick, you should know how to diagnose an FC by now. lol
i also hear detonation so be sure your ignition wires on the trailings are going to the proper rotor, check CAS timing, etc.
i also hear the fan more than the exhaust so either your fan is stuck on completely or your exhaust is plugged up and needs an enema.
beyond that check the fuel pressure, that will cause a major issue with power like this especially at the transition after 4k. follow that up with cleaning the injector ground under the UIM to the rear rotor housing.
i also hear detonation so be sure your ignition wires on the trailings are going to the proper rotor, check CAS timing, etc.
i also hear the fan more than the exhaust so either your fan is stuck on completely or your exhaust is plugged up and needs an enema.
beyond that check the fuel pressure, that will cause a major issue with power like this especially at the transition after 4k. follow that up with cleaning the injector ground under the UIM to the rear rotor housing.
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There's no fan on the car at the moment lol. I think you're hearing the air pump. The exhaust probably is clogged a little. It has the pre-cats and the main cat on it still. The exhaust smokes a bit when I idle the car up to temp. I didn't want to buy a header or anything until I got the POS running right and smogged.
As far as grounds go - I've cleaned/sanded the connection point under the UIM on the rat's nest. I've also cleaned and sanded the grounds that I could find by the shock towers. I'll have to check if I've cleaned the injector ground to the rear housing though...if it helps I've spliced into the ground wires pretty close to the ecu to ensure that they are grounded.
I guess the next thing I can do is get a fuel pressure tester from Oriley's and see what it's putting out.
As far as grounds go - I've cleaned/sanded the connection point under the UIM on the rat's nest. I've also cleaned and sanded the grounds that I could find by the shock towers. I'll have to check if I've cleaned the injector ground to the rear housing though...if it helps I've spliced into the ground wires pretty close to the ecu to ensure that they are grounded.
I guess the next thing I can do is get a fuel pressure tester from Oriley's and see what it's putting out.
#19
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they loan them also if you don't want to fork out to actually buy one, just get your money back after you're done with it. as for the exhaust, try dropping it and inspect it to see if it looks clogged, or loosen it up and see if it revs freely with it loose. also be sure to check your timing and wires, i hear what really sounds like preignition from some possibly really fucked up timing.
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Found out that my trailing plug wires were mixed up. I put them back where they belong and nothing has changed:
https://www.youtube.com/watch?v=Qiri...ature=youtu.be
This weekend I will test fuel pressure and check timing.
https://www.youtube.com/watch?v=Qiri...ature=youtu.be
This weekend I will test fuel pressure and check timing.
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There's no fan on the car at the moment lol. I think you're hearing the air pump. The exhaust probably is clogged a little. It has the pre-cats and the main cat on it still. The exhaust smokes a bit when I idle the car up to temp. I didn't want to buy a header or anything until I got the POS running right and smogged.
As far as grounds go - I've cleaned/sanded the connection point under the UIM on the rat's nest. I've also cleaned and sanded the grounds that I could find by the shock towers. I'll have to check if I've cleaned the injector ground to the rear housing though...if it helps I've spliced into the ground wires pretty close to the ecu to ensure that they are grounded.
I guess the next thing I can do is get a fuel pressure tester from Oriley's and see what it's putting out.
As far as grounds go - I've cleaned/sanded the connection point under the UIM on the rat's nest. I've also cleaned and sanded the grounds that I could find by the shock towers. I'll have to check if I've cleaned the injector ground to the rear housing though...if it helps I've spliced into the ground wires pretty close to the ecu to ensure that they are grounded.
I guess the next thing I can do is get a fuel pressure tester from Oriley's and see what it's putting out.
#24
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i got 3 main cats left
they're still good, the FD main is still almost brand new but the damn EPA is such a ******* pain in the ***.... regulating sales and requiring you buy a junk $100 inferior CARB cert cat instead or pay more than the car is worth for new OEM.
the other cat guy who came by said the FC main cats(i have 2 left) were only worth $60 each, i gave him the finger.
they're still good, the FD main is still almost brand new but the damn EPA is such a ******* pain in the ***.... regulating sales and requiring you buy a junk $100 inferior CARB cert cat instead or pay more than the car is worth for new OEM.
the other cat guy who came by said the FC main cats(i have 2 left) were only worth $60 each, i gave him the finger.
Last edited by RotaryEvolution; 07-13-15 at 08:02 PM.
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