Need help diagnosing engine running rough

[SalvadorP]

Originally Posted by baggy798

I'm surprised your 97 car has EGR, mine doesn't but that valve is located here. You can also see how I plugged the evap ports. One is the same size plug as the intake manifold ports, the other I just used a silicone hose and spare screw from inside car.😅 Been like that for 8+ years.

I also just use small zip ties to secure the hoses on rather than those horrible clips! I find that the silicone vacuum hoses tends to 'stick' to the ports very well, never had a hose blow off.

Honestly. I don't think mine has an EGR either and it's not the first time I make this confusion. I did the vacuum hoses today and the lines in the diagram I posted weren't there. What happens is that I confuse the Idle Air Control Valve with an EGR, they just look similar to me, so I believed the diagrams in the catalogue. My car took less hose because of this.

I also used zip ties but I was planning on ordering some clips from amazon. I guess at least for the turbo, because of the temperature, maybe I'll just use regular clamps.

Thanks for the pic of the can. I actually took a pic of mine. I thought I had uploaded it but I guess I forgot. Today I found an open 4mm plastic hose that ends right besides the can and would fit perfectly inside the "tank" bit of hose that is on the canister. I couldn't check where the tube led to, but it ran alongside the engine bay and bellow the firewall. I assume it goes all the way to the tank. Maybe the last mechanic forgot to plug it. I'll probably have to jack up the car to be sure.

Thanks for the help.
Salvador

[360beast]

EGR was MY1995 only I believe as I've only ever seen it on MY1995 cars, best thing to do is blank it off and pull the useless stuff off of it and then there's no chance of problems further down the line and it is way easier to clean the PCV system without it in the way.

[griston64]

Originally Posted by 360beast

EGR was MY1995 only I believe as I've only ever seen it on MY1995 cars, best thing to do is blank it off and pull the useless stuff off of it and then there's no chance of problems further down the line and it is way easier to clean the PCV system without it in the way.

It's on my 96 car Luke. Never seen it on a 97 though

[360beast]

Originally Posted by griston64

It's on my 96 car Luke. Never seen it on a 97 though

Your car was probably built in the tail end of 95 as I know yours is a 96 but the cars I've seen that are date stamped 96 on the cylinder head don't have it.

If you look at your cylinder head it will be date stamped with three circles that will say something like 4 4 95 which is 4th day of the 4th week of 1995. I found out my 97 940 was built in 96 that way.

[SalvadorP]

So, I have cleaned and refurbished the injectors and my car still has a crappy idle. It fluctuates between 800 and 900 and makes the car shake when it drops to the lower value.

Although I do not notice any misfire at other rpm, the car shakes quite significantly around 1500 to 1800 if I remember correctly.

I've gone through all the steps listed in another posts.
So now I'm down to idle valve, MAF, distributor, CPS or lambda.
Having said that, I don't wanna just fire the parts canon.

Also I have a couple other theories that maybe don't make no sense. Is it possible that a bad harmonic balancer maybe cause this symptoms? On the same note, can a crankshaft related issue cause this?

What would you do?

[Laird Scooby]

Originally Posted by SalvadorP

So, I have cleaned and refurbished the injectors and my car still has a crappy idle. It fluctuates between 800 and 900 and makes the car shake when it drops to the lower value.

Although I do not notice any misfire at other rpm, the car shakes quite significantly around 1500 to 1800 if I remember correctly.

I've gone through all the steps listed in another posts.
So now I'm down to idle valve, MAF, distributor, CPS or lambda.
Having said that, I don't wanna just fire the parts canon.

Also I have a couple other theories that maybe don't make no sense. Is it possible that a bad harmonic balancer maybe cause this symptoms? On the same note, can a crankshaft related issue cause this?

What would you do?

Have you put a NOID light on each of the injectors in turn to confirm they're firing at low rpm? Also have you tried running the engine at those speeds in darkness to see if you can see any arcing on the HT side?

Also while it's dark, take an LED torch with you (dimmable variety) and use it in the engine bay on the dim setting to see if any coolant is escaping and spraying the HT leads/plugs/dizzy cap with water (when on dim, the LED is pulsed so "freezes" the moving water droplets) and along similar lines, the T-valve for the washer jets on the bonnet can leak onto the dizzy cap causing similar.

[SalvadorP]

Originally Posted by Laird Scooby

Have you put a NOID light on each of the injectors in turn to confirm they're firing at low rpm? Also have you tried running the engine at those speeds in darkness to see if you can see any arcing on the HT side?

Also while it's dark, take an LED torch with you (dimmable variety) and use it in the engine bay on the dim setting to see if any coolant is escaping and spraying the HT leads/plugs/dizzy cap with water (when on dim, the LED is pulsed so "freezes" the moving water droplets) and along similar lines, the T-valve for the washer jets on the bonnet can leak onto the dizzy cap causing similar.

Answering your first question. No, I only used a screwdriver to listen to the injectors and they were firing alright/consistently.

I haven't done any light/dark testing. I will look into the leak theory, but I feel it's so consistent and almost rythmic like you have said back then, that it must be more of a consistent source. But well, I'm not discarding anything right now. I'm down to the most expensive culprits, and I would like to find it and not just randomly throuw 1000€ of parts at the car for no reason. But this is proving a case hard to crack.

[Laird Scooby]

Originally Posted by SalvadorP

Answering your first question. No, I only used a screwdriver to listen to the injectors and they were firing alright/consistently.

I haven't done any light/dark testing. I will look into the leak theory, but I feel it's so consistent and almost rythmic like you have said back then, that it must be more of a consistent source. But well, I'm not discarding anything right now. I'm down to the most expensive culprits, and I would like to find it and not just randomly throuw 1000€ of parts at the car for no reason. But this is proving a case hard to crack.

When you do find the answer, it will be obvious with all the evidence you've gathered. Probably something simple as well

[SalvadorP]

Originally Posted by Laird Scooby

When you do find the answer, it will be obvious with all the evidence you've gathered. Probably something simple as well

This has been scrambling my brain cells for amlost 2 years now.

[SalvadorP]

Originally Posted by Laird Scooby

When you do find the answer, it will be obvious with all the evidence you've gathered. Probably something simple as well

Forgot to mention the clue found by baggy when I swapped turbos. He mentioned that the white deposit would suggest a lean condition, which would increase temp and therefore damage the turbo.

So a lean condition might be part of it, not the culprit, but anither symptom, clue... I need to remove plug to check and maybe do a compression another test.