Loss of power after timing chain guides were removed

[Jagstang]

I have a 1995 240sx Base Model SE, and I took it to the mechanic yesterday to remove the timing chain guides. They did a great job, and the engine runs smoothly, and quietly (without the damn rattle sound).

Anyways, before I paid them, I took it for a spin, and I noticed the car is weak. It doesn't accelerate as fast as it used to. By this, I mean the fact that it picks up slowly all the way to the redline.

And before I took it in, I installed new spark plugs and wires, new cap rotor, and I also seafoamed it (both the gas tank, which was one full can), and the power brake booster line (about 80% of the can in there).

So anyways, I brought it up to the mechanic, and he said that it could be the o2 sensor, or it could be the fact that they need to time the distributor higher than what it's at right now (850). So I was just wondering, what do you guys think may be the problem?

Help would be greatly appreciated, thanks in advance.


Modified by Jagstang at 9:20 PM 7/8/2009

[SR24DET]

Y dont you play with the distributor and see what happens?

[driftneil]

Whats your idle like?

[fijianrocket]

I have heard that sometimes the seafoam will mess with the o2 sensor. But I haven't experienced that myself.

[Kraelic]

I'd suspect the timing as well. I didnt follow the proper procedure to time the engine and it felt weak after the guide removal. My timing light was showing 20 degrees before TDC. Then I found out which sensor was the throttle position sensor and unplugged it to time it proper. I set mine to 16 degrees before TDC instead of the stock 20.

[Kraelic]

Just read the part about timing it higher than 850 rpms.. yeah they have the timing set wrong. the idle air control screw sets the rpm not the distributor.

[Jagstang]

Y dont you play with the distributor and see what happens?

The distributor, or you mean the idle air control valve?

Whats your idle like?

My idle is smooth, and the RPM's are at 850. It doesn't bog or misfire etc. It only does that when I accelerate while driving.

I'd suspect the timing as well. I didnt follow the proper procedure to time the engine and it felt weak after the guide removal. My timing light was showing 20 degrees before TDC. Then I found out which sensor was the throttle position sensor and unplugged it to time it proper. I set mine to 16 degrees before TDC instead of the stock 20.

Hmm ok. So i'll probably have to get timing light. Do you by any chance remember what kind of timing light you have? Cause I don't want to buy a crappy one that will get my timing all screwed up etc.

Just read the part about timing it higher than 850 rpms.. yeah they have the timing set wrong. the idle air control screw sets the rpm not the distributor.

Alright, so what does the distributor do exactly? It doesn't affect the RPM's or the misfiring i'm experiencing?

[driftneil]

It accounts for the misfiring, not the rpm's.If you look at the back pass side of the motor. In front of the purple plug in the back. There is a screw, Thats yourr pm adjustment.

[Jagstang]

OMG, I think I may have figured out the problem. . . I just opened my engine bay, and looked at the wires, and I noticed that they're not in the correct spots... In this tutorial, it says the spark plug wires need to be in this particular order...



Well this is the order my wires are in. . .



As you can see, from my picture, my wires are not the same as the other one. . . My top left wire is 4, my top right wire is 3, my bottom left wire is 2, and my bottom right is 1. . .

Do you think that may be the problem? Because the mechanic timed the engine with that setup. . . So? Do you think I may be on to something?

Let me know, thanks in advance everybody.

[sloweighty]

ok, did you just replace the guides or everything because from what i learned from working with timing chains on 240's is that the chain does stretch (correct me if i am wrong) if you get rattles on a cold start and i think that could make you lose power

[TimTurboZ]

Did you go ahead and try swapping the wires to the correct location??? Seems you had plenty of time to edit a pic for us...Definately would be an issue. Wonder why it idles so well tho. Then again I accidently mixed up ECU's and had a SOHC ECU running my DOHC. Idled perfectly for like 10 minutes....so normal idle with mismatched plugs isn't the strangest thing i've heard of swap em and tell us how it turns out. (My friend mixed up the wires on his 5.0 and it idled fine but didn't have normal power either)