1993 sc400 Hesitating acceleration
#1
1993 sc400 Hesitating acceleration
Still trying to get this car running right that I bought recently. I sent the ecu out to Tanin and I trust there work since thats what they do so I have to figure out whats wrong...could use some input from you helpful folks.
I have hesitation beginning just before 1500 rpm and it continues throughout the whole rpm range. At times the engine will buck harshly and falls on its face while driving during acceleration. I know its not the ecu...Cap and rotor look great, the wires look fine, someone replaced them before.
What are some more things I should check? Local people who Ive talked to say the timing belt could have jumped a tooth...how common is this?
* guess what I am looking for is input from common problems for these cars...I have no CEL and ECU is verified and tested good.
Thank You all
I have hesitation beginning just before 1500 rpm and it continues throughout the whole rpm range. At times the engine will buck harshly and falls on its face while driving during acceleration. I know its not the ecu...Cap and rotor look great, the wires look fine, someone replaced them before.
What are some more things I should check? Local people who Ive talked to say the timing belt could have jumped a tooth...how common is this?
* guess what I am looking for is input from common problems for these cars...I have no CEL and ECU is verified and tested good.
Thank You all
Last edited by 93sc400nm; 11-29-16 at 09:28 PM.
#7
Update
I drove the car around tonight and magically the hesitation is only at 1400 to 1500 rpm instead of all the way through the powerband...I think the ecu just needed time to relearn things.
Now I have a whining belt noise! Could this be due to the cold or bad timing belt? idler or tensioner?
Anyone have a whining belt before? I think its just time to put a fresh belt and tensioner on this car.
Now I have a whining belt noise! Could this be due to the cold or bad timing belt? idler or tensioner?
Anyone have a whining belt before? I think its just time to put a fresh belt and tensioner on this car.
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#11
If it is one of the two ignition coils, the vehicle should sound like a 4 cylinder, and drive like a semi. (go 90 down the hill to make it up the next at 60..) personal experience
#13
Update again
Another update...this car has been sitting for a few years and its old so one thing will break after the next for a while. Has 133,000 for its age that is great I think.
Weird belt noise was actually my power steering pump...return not sender was leaking...waiting on replacement hose. However, I would like to mention that Prestone power steering with stop leak has for the time completely stopped the leak so I highly recommend, surprised it worked.
Coils will be here tomorrow
New problem, the e brake indicator light is turning on at times during acceleration...is this a signal the car is telling me something is wrong? Would this be my brake pad is low indicator or is that a separate light? ...or something else entirely? Thanks for the help, particularly t2d2 for continued help I give you a thanks
Weird belt noise was actually my power steering pump...return not sender was leaking...waiting on replacement hose. However, I would like to mention that Prestone power steering with stop leak has for the time completely stopped the leak so I highly recommend, surprised it worked.
Coils will be here tomorrow
New problem, the e brake indicator light is turning on at times during acceleration...is this a signal the car is telling me something is wrong? Would this be my brake pad is low indicator or is that a separate light? ...or something else entirely? Thanks for the help, particularly t2d2 for continued help I give you a thanks
Last edited by 93sc400nm; 12-06-16 at 05:50 PM.
#14
I've never dealt with the e-brake warning light coming on, but I would assume it's either a mechanical or electrical thing. If it's mechanical, you would surely notice it dragging. If it's electrical, it could be a gauge cluster issue, but is more likely the sensor on the e-brake handle itself.
I'm not sure how to troubleshoot that, but there's a little 1-wire sensor that screws to the front lower portion of the e-brake handle's base. I suppose it could be as simple as something got on or around it and is enough to make the sensor think the handle is raised (no contact between sensor and handle), or it could be a break in the wire.
If it is a faulty wire, there's a junction not far down the line, so maybe you can replace the sensor without any rewiring difficulty.
We don't have a brake pad wear indicator that I know of. The LS400 does and that sensor gets discarded when installed on SCs.
I'm not sure how to troubleshoot that, but there's a little 1-wire sensor that screws to the front lower portion of the e-brake handle's base. I suppose it could be as simple as something got on or around it and is enough to make the sensor think the handle is raised (no contact between sensor and handle), or it could be a break in the wire.
If it is a faulty wire, there's a junction not far down the line, so maybe you can replace the sensor without any rewiring difficulty.
We don't have a brake pad wear indicator that I know of. The LS400 does and that sensor gets discarded when installed on SCs.
#15
Ok good to know, I will check this out tomorrow and check for the possible mechanical issue that makes sense...there definately is no contact with the e brake and i could see how the little bit of acceleration force might turn and indicator on...i will send the cluster to Tanin down the road because I do have the faulty flashing needle and half of the gauge is lit up.