Mr2 Mk2 Acceration Problem

[classicol]

Have this problem when I accelerate hard. The engine sounds like a V8, it roars, but no acceleration. If I accelerate slowly then it picks up like it should. Originally thought it was missing but it isn't(Please ignore previous message). Also happens in any gear on full acceleration(foot to the floor) or if I depress the throttle past about halfway. The engine is superb otherwise. The roar sounds like too much air entering the engine. Anyone had this problem? I'm sure its not the leads dizzy or plugs, they look new.

[classicol]

Have this problem when I accelerate hard. The engine sounds like a V8, it roars, but no acceleration. If I accelerate slowly then it picks up like it should. Originally thought it was missing but it isn't(Please ignore previous message). Also happens in any gear on full acceleration(foot to the floor) or if I depress the throttle past about halfway. The engine is superb otherwise. The roar sounds like too much air entering the engine. Anyone had this problem? I'm sure its not the leads dizzy or plugs, they look new.

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Sorry about title meant ACCELERATION not acceration. Sounds like I'm drunk. Constanoon afterbal

[Bobby-H]

Have this problem when I accelerate hard. The engine sounds like a V8, it roars, but no acceleration. If I accelerate slowly then it picks up like it should. Originally thought it was missing but it isn't(Please ignore previous message). Also happens in any gear on full acceleration(foot to the floor) or if I depress the throttle past about halfway. The engine is superb otherwise. The roar sounds like too much air entering the engine. Anyone had this problem? I'm sure its not the leads dizzy or plugs, they look new.

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Have you checked the spark plugs, ignition leads and distributer cap?

[classicol]

Have this problem when I accelerate hard. The engine sounds like a V8, it roars, but no acceleration. If I accelerate slowly then it picks up like it should. Originally thought it was missing but it isn't(Please ignore previous message). Also happens in any gear on full acceleration(foot to the floor) or if I depress the throttle past about halfway. The engine is superb otherwise. The roar sounds like too much air entering the engine. Anyone had this problem? I'm sure its not the leads dizzy or plugs, they look new.

←

Have you checked the spark plugs, ignition leads and distributer cap?

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They all look new and perfectly serviceable. I doubt that is the problem. It faulters if you press the throttle down hard for a few seconds in neutral and then picks up. In any gear whilst driving any pedal to the metal produces a loud roar from the rear but precious little acceleration which does not improve until you ease off the throttle and then apply it slowly which gives you adequate acceleration until about half throttle when it back to roaring again. It feels and sounds like too much air or too little petrol! No backfiring though and no missing. There is no problem with the clutch either. Thanks for your suggestion.

[Bobby-H]

Have this problem when I accelerate hard. The engine sounds like a V8, it roars, but no acceleration. If I accelerate slowly then it picks up like it should. Originally thought it was missing but it isn't(Please ignore previous message). Also happens in any gear on full acceleration(foot to the floor) or if I depress the throttle past about halfway. The engine is superb otherwise. The roar sounds like too much air entering the engine. Anyone had this problem? I'm sure its not the leads dizzy or plugs, they look new.

←

Have you checked the spark plugs, ignition leads and distributer cap?

←

They all look new and perfectly serviceable. I doubt that is the problem. It faulters if you press the throttle down hard for a few seconds in neutral and then picks up. In any gear whilst driving any pedal to the metal produces a loud roar from the rear but precious little acceleration which does not improve until you ease off the throttle and then apply it slowly which gives you adequate acceleration until about half throttle when it back to roaring again. It feels and sounds like too much air or too little petrol! No backfiring though and no missing. There is no problem with the clutch either. Thanks for your suggestion.

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Yes, it that case I would say the engine isn't getting enough fuel, this could be caused by loads of things:

First of all, check the ECU for fault codes if nothing shows up you could try:

Checking for air leaks on the intake manifold and connecting pipes, dont forget to check for leaks in the vacume pipe for the brake servo.

Check for a blocked fuel filter

Check the throttle position sensor is working properly

Check the TVIS is working properly (if you have it on your car)

It could also be a faulty fuel pressure regulator, you could check this is you have a suitable guage, otherwise get a garage to check it for you. Also check that the fuel pump is putting out enough pressure.

You should be able to find a workshop manual on the internet to tell you how to do all of the above.

[classicol]

Have this problem when I accelerate hard. The engine sounds like a V8, it roars, but no acceleration. If I accelerate slowly then it picks up like it should. Originally thought it was missing but it isn't(Please ignore previous message). Also happens in any gear on full acceleration(foot to the floor) or if I depress the throttle past about halfway. The engine is superb otherwise. The roar sounds like too much air entering the engine. Anyone had this problem? I'm sure its not the leads dizzy or plugs, they look new.

←

Have you checked the spark plugs, ignition leads and distributer cap?

←

They all look new and perfectly serviceable. I doubt that is the problem. It faulters if you press the throttle down hard for a few seconds in neutral and then picks up. In any gear whilst driving any pedal to the metal produces a loud roar from the rear but precious little acceleration which does not improve until you ease off the throttle and then apply it slowly which gives you adequate acceleration until about half throttle when it back to roaring again. It feels and sounds like too much air or too little petrol! No backfiring though and no missing. There is no problem with the clutch either. Thanks for your suggestion.

←

Yes, it that case I would say the engine isn't getting enough fuel, this could be caused by loads of things:

First of all, check the ECU for fault codes if nothing shows up you could try:

Checking for air leaks on the intake manifold and connecting pipes, dont forget to check for leaks in the vacume pipe for the brake servo.

Check for a blocked fuel filter

Check the throttle position sensor is working properly

Check the TVIS is working properly (if you have it on your car)

It could also be a faulty fuel pressure regulator, you could check this is you have a suitable guage, otherwise get a garage to check it for you. Also check that the fuel pump is putting out enough pressure.

You should be able to find a workshop manual on the internet to tell you how to do all of the above.

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Thanks Bobby-H for the constructive thoughts. Will get to it tomorrow. Thanks again.

[TOYMOTA]

I've no experience with MR2's (apart from the 4A-GE engine in the Mk1) but on instinct i'd say lack of fuel. Cr@p in the fuel line perhaps? What's the fuel filter like? Clean / Dirty? Been replaced recently?? This could have happened if you ran it very low on fuel one day and the engine sucked up some muck from the bottom of the tank!

[classicol]

I've no experience with MR2's (apart from the 4A-GE engine in the Mk1) but on instinct i'd say lack of fuel. Cr@p in the fuel line perhaps? What's the fuel filter like? Clean / Dirty? Been replaced recently?? This could have happened if you ran it very low on fuel one day and the engine sucked up some muck from the bottom of the tank!

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Thanks TOYMOTA. Will check that tomorrow. I did run it a bit low once.

[TOYMOTA]

If there is cr@p in the fuel line then the easiest way to get rid of it is to disconect the fuel line at the fuel filter, take the fuel filler cap off (to get rid of any pressure) the fuel sender pipe, and then blow like made down the fuel line from the filter end. Any cr@p will/should be pushed back into the tank. Then you can either flush the tank or leave it and don't run her too low in future.

[AE82 GT]

sorry to state the obvious but if the engine is running and revving, with no stuttering or hesetation then its the clutch slipping, so its either knackered or the plats have been contaminated with oil or somthing.

[classicol]

sorry to state the obvious but if the engine is running and revving, with no stuttering or hesetation then its the clutch slipping, so its either knackered or the plats have been contaminated with oil or somthing.

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I see where you are coming from but the clutch is perfect. The engine does not pick up revs immediately but hesitates on pedal to the metal throttle EVEN in neutral. Thanks anyway.

[classicol]

It turned out to be the throttle position sensor was faulty. Have replaced it and am now enjoying full acceleration over complete range.