My Old Mans Celica Wierd Acceleration Problem?

[Skooter]

My old man has a 1993 (Gen5?) Celica GT.

He bought it 12 years ago as an ex-demo for £15,000(!). It now has 90k on the clock, but it has FSH.

About a month or so ago he started experiencing a problem with the acceleration. Bascially when he pushes the accelerator, it takes forever to go anywhere. Once he gets going it's not too bad, but obviously he has a problem! *lol* He says that when idling, the engine revs freely & there's no clutch slip.

The first thing he did was to get the car serviced to see if that helped, but no improvement at all. The Toyota mechanic checked the fuel flow, exhaust emissions, cam timing which was all fine. The diagnostics machine showed no problems...! The only thing that he could think of was maybe the ECU was faulty?

He said that he could look at it, but as he didn't know what was wrong, he couldn't guarantee a fix.

The poor blokes had a tough couple of months. My mum died of cancer in July. Then the following week his TV died. Then his car started playing up. We gave him our dog to keep him company for a few weeks & we now find out that my dog had cancer too. Unbelievable huh :-(

He must be low, as he even looked at buying a 2004 Honda Civic Type-S today! And it was a 5-door!! :-)

I'm posting here hoping that maybe someone else has experienced a similar problem, or could possibly offer some advice as to what it might be.

Thanks it advance,

Scott.

[mikeb]

Have you checked the idle switch on the throttle position sensor? It's about the only thing I can think of if the fuel system has been given the AOK.

It could possibly be the MAP sensor too, but I would have thought the ECU would have thrown a fault code if it bad enough to make the car undriveable.

[Skooter]

Cheers Mike

I'm gonna pop over on Sunday & have a look.

Don't suppose you could describe where the throttle position sensor & the idle switch are locate please. I've never worked on his car before. I've just ordered a Haynes repair manual off Amazon, but it'll take a couple of days to arrive.

Somebody also suggested to me to try some Redex petrol injector treatment?

Also suggested was to trycleaning the throttle body with some carb cleaner?

[mikeb]

I don't think it will be caused by a dirty throttle body, but a dose of redex can't hurt to clean the injectors.

The TPS and idle switch are all in one unit, mounted on the end of the throttle spindle (in the upper left of this pic, the 4 pin connector):

Here's the relevent section from the Hayne's manual:

To test it (with the engine off), unplug the TPS connector and put a multimeter across IDL and E2 pins of the sensor. Set to measure continuity/resistance. It should be closed circuit/0 ohms when the throttle is closed. Open the throttle by turning the throttle cable linkage, and the switch should go open circuit as soon as soon as the throttle starts to move.

You can also check the analogue part of the TPS by measuring resistance across E2 and VTA pins of the sensor. The resistance should change continuously (roughly between 0 and 5k ohms) as you open the throttle.

Also check the connector pins for corrosion.

[Skooter]

Mike......you are indeed a star

[mikeb]

Mike......you are indeed a star 

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I wouldn't say that yet - we might be barking up totally the wrong tree!

[Skooter]

True true

Well i'll check a few things out at the weekend & post back my findings.

Have a good weekend matey :)

[Skooter]

My old man put a deposit down on that Honda yesterday

Surely there's better cars to spend 12 grand on?

Ah well, thanks for the advice everyone

[daktari]

My old man put a deposit down on that Honda yesterday 

Surely there's better cars to spend 12 grand on? 

Ah well, thanks for the advice everyone 

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Bet he regrets it after a while.

[GTForbes]

he will, Skooter, ever thought about taking hte celica for yourself?

what was changed in the service? if there's hesitation with the acceleration then it could be dodgy leads or fouled plugs

[Skooter]

Skooter, ever thought about taking hte celica for yourself?

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I did at one point, as it can only be worth a few hundred quid in it's current condition......but then the Honda garage offered him about £1150 for the Celica in P/X. If it was cheap i would've. But i've just bought another project bike (NSR 250), so not that interested tbh.