Pinking and stuttering

[Jassy]

Firstly let me thank anyone who has responded to any of my earlier pleas for help. I did raise the issue of pinking (I think in US you call it pinging) and thought the problem might be the knock sensor, unfortunately I have not had an opportunity to get under the car to test it yet, however I have another problem and wonder if they are linked.

So 1st problem is pinking on hard acceleration or going up hill, I have to change down further than needed or do not accelerate so hard.

The 2nd problem is, if I am going downhill and want to let the engine do the braking the car stutters almost like putting foot on brake then off again. I do not see any changes in the revs. Braking or giving it a bit more gas and the problem disappears.

I have checked for any errors on the ODBII and the only error is a an ECU checksum error which can not be reset.

Anyone had both these errors on their car or maybe have any ideas?

Again thank you guys for all your valued help.

[CREWZIN]

First tell us if you have the 2.4 Ltr gasoline engine or one of the others they sell in Europe.

[Jassy]

Thanks CREWZIN

Yes, I suppose it would help! It's the 2.0L Petrol engine.

Tony

[CREWZIN]

At least it's not a diesel, then all bets are off. Don't suppose the 2.0 is that much different from out 2.4

Sure sounds to me like the timing may be off. On our, the timing belt would have to be slipping or after changing it, it would be a tooth off. Is there a way on your 2.0 that the timing can be adjusted?

The knock sensor should take care of the timing being a little bit off or the wrong grade of gas being used. You did say you haven't had time to look at that. It's a cheap and easy fix.

[Jassy]

Interesting, only had the car a couple of months and previous owner did say that she had the timing belt replaced recently. Is there an easy way to check the timing is correct? And more importantly is it easy to slip a tooth to correct the timing if it is off or is it a major job?

[CREWZIN]

Here's a couple of threads to look over for the timing belt check.

2001 Timing Belt Broke

Please Help!! Timing belt replaced and having engine problems

[Jassy]

Firstly, thanks Crewzin for your answers and help.

Finally got under car today! I can see knock sensor from above and below but just cannot get to it. I am thinking of dropping the radiator forward just to get to it, but is there an easy way to test without doing this? Where does the wire go once it gets in to the loom, just wondering if I can get to the other end and monitor this whilst I (somehow) tap the sensor.

[CREWZIN]

Don't have an answer to those questions as I've never had to test it or to remove it.

[randyincctx]

Originally Posted by Jassy

1st problem is pinking on hard acceleration or going up hill, I have to change down further than needed or do not accelerate so hard.
The 2nd problem is, if I am going downhill and want to let the engine do the braking the car stutters almost like putting foot on brake then off again. I do not see any changes in the revs. Braking or giving it a bit more gas and the problem disappears.

The 1st & 2nd problems are probably related to one another....Generally;there are 6 problems that can cause your 1st symptom.

"Pinging or knocking engine sounds during acceleration or uphill":

1- Incorrect grade of fuel
2- Problem with the engine control system
3- Fuel injection system faulty
4- Improper or damaged spark plugs or wires
5- EGR valve not functioning
6- Vacuum leak
(Source: Hanes Repair Manual)

Since you say: "I have checked for any errors on the ODBII and the only error is a an ECU checksum error which can not be reset.".......I'm personally leaning towards #2.

[Gold2006]

Originally Posted by randyincctx

The 1st & 2nd problems are probably related to one another....Generally;there are 6 problems that can cause your 1st symptom.

"Pinging or knocking engine sounds during acceleration or uphill":

1- Incorrect grade of fuel
2- Problem with the engine control system
3- Fuel injection system faulty
4- Improper or damaged spark plugs or wires
5- EGR valve not functioning
6- Vacuum leak
(Source: Hanes Repair Manual)

Since you say: "I have checked for any errors on the ODBII and the only error is a an ECU checksum error which can not be reset.".......I'm personally leaning towards #2.

7-Carbon build up in combustion chamber causing pre-ignition. For that problem and dirty fuel injectors, I use the AMSOIL fuel system cleaner.