Bucking like a bronco.
DonSor
08-24-2007, 11:13 PM
Got this 91 Mitsubishi 3000GT SL. I just completed preping it after being non-opd for five years. Everything well well during run tests with the exception of the following: When I first step on the gas, the car will move smoothly but then it will starting "bucking" or "surging" until it gains speed. It did not feel like the engine was missing. It did not feel like the clutch was slipping either. Once I slow down it will start doing it again. However, when I go past 30MPH and on to high speed runs, the car runs great. The engine idles good and I don't seem to have any clutch or tranny problems. No Check Engine Light indication. Any ideas what it could be?
Twizted_3KGT
08-25-2007, 01:19 AM
Is there 5 year old watery gas in the tank? How's the spark plugs look?
Stealthee
08-25-2007, 10:22 AM
plugs, wires, fuel, fuel filter, etc etc etc
DonSor
08-25-2007, 11:44 PM
Good probability is that I got some contamination (oncluding water) in the gas. I'm adding a can of Seafoam fuel cleaner. No way to get rid of the contaminated gas but I added five gallons of fresh gas. I'll start using the car which by the way is driveable until I expend most of the bad gasoline. Plugs look good but I think the fuel filter needs changing. Other than that the car runs good especially in acceleration and high freeway speeds.
Stealthee
08-26-2007, 09:02 AM
You do know theres a drain on the bottom of the tank dont you? Drain that shit out of there.
DonSor
08-26-2007, 11:13 PM
No I don,t but I'll check on that. While on the subject of this car, I have a question. I've noticed that I have a drain on the battery even with the ignition key off. I disconnected the battery. Took a resistance reading between the positive lead from the starter and ground and got infinity however, when I took a resistance reading between the positive lead to the accessories and ground I got a reading of about 12K ohms. Shouldn't that be infinity or resistance in the megs as well. Unless theres a circuit that is always hot even with the igition key off.
Igovert500
08-27-2007, 09:50 AM
Locating source of battery drain (http://www.3si.org/forum/showthread.php?t=328317)
DonSor
09-03-2007, 01:23 PM
Found the plug and drained the old fuel. Also replaced the fuel filter. Still does the same thing when slightly pressing on the accelerator. Does not do it during deceleration nor does it happen during medium to full throttle. That phase when you first place it in first gear and start to press on the accelerator when this happens but not all the time. Frustrating I might say.
On the subject of battery drain, fortunately I have a copy of the factory manual. First question is: With the ignition switch closed and no accessories or lights on, is there anything in the system such as alarm or any of the control units remain energized that could cause the battery to go dead after a period of time?
When I disconnected my accessory lead from the battery terminal and took a resistance reading to ground, I was getting very low resistance reading (about 7Kohms). When I removed the #6 fusible link in the Centralized junction Box however, the reading went up to over 50Kohms which is better but perhaps still not normal. Shouldn't I be reading in the Megohm range?I started removing various fuses in the Multi-purpose fus box fed by #6 and found that the circuit causing low reading was fuse #19 (rated at 10A). Ckt#19 feeds the following:
Engine Control Unit
ELC-4A/T Control Unit
ETACS Unit
Dome Lit
Foot Light
Door Light
Luggage Compartment Light
Combination Meter
A/C control Unit
Auto Cruise Control Unit
Audio
Seatbelt Solenoid
Electronic Control Suspension Control Unit
Active Aero Control Unit (NA)
On the subject of battery drain, fortunately I have a copy of the factory manual. First question is: With the ignition switch closed and no accessories or lights on, is there anything in the system such as alarm or any of the control units remain energized that could cause the battery to go dead after a period of time?
When I disconnected my accessory lead from the battery terminal and took a resistance reading to ground, I was getting very low resistance reading (about 7Kohms). When I removed the #6 fusible link in the Centralized junction Box however, the reading went up to over 50Kohms which is better but perhaps still not normal. Shouldn't I be reading in the Megohm range?I started removing various fuses in the Multi-purpose fus box fed by #6 and found that the circuit causing low reading was fuse #19 (rated at 10A). Ckt#19 feeds the following:
Engine Control Unit
ELC-4A/T Control Unit
ETACS Unit
Dome Lit
Foot Light
Door Light
Luggage Compartment Light
Combination Meter
A/C control Unit
Auto Cruise Control Unit
Audio
Seatbelt Solenoid
Electronic Control Suspension Control Unit
Active Aero Control Unit (NA)
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