I have a problem with my 1992 SE 5 speed. From the start, something seems to be holding the car back, get on the throttle and its as if the brake is still on, it does not want to rev (this had me thinking clogged cat converter). As the car warms up, it will start to buck, then the car will slow to a stop, bucking the whole way. Once stopped, it will continue to idle, but when you mash the throttle it does not want to rev and will rev irratically, and not much past 1000 rpm, mash it a little harder and it will stall. Cut the key off, immediately restart the car, and it will run semi normal for a few minutes down the road and start behaving badly again.

No codes on dash, no 2500 rpm limit. Any ideas? I just replaced 3 coilpacks that were cracked, and am about to order a knock sensor, tps, and temp sensor unless someone has a better idea...

 

Also, rev the car to around 5k, let off slowly and rpms will surge upward a bit before coming down. This made me think tps, but not sure.

 

Check the CPS and clean up all electrical connections especially the grounds. Swap MAF too.

 

Cps... Camshaft position sensor or crank sensor?

 

Camshaft position sensor...

 

Update: symptoms are worsening. I swapped mafs with my vg car (same part number believe it or not). Nothing changed.

Cam sensors are not cheap so I will not be able to buy one in the next few weeks, unless someone has a used one laying around I could buy from them... Still have no real lead on this... I've had thoughts of fuel pump, cat converter, fuel filter (probably will change anyway), just keep thinking its got to be a sensor because of the fact that heat plays a role, and shutting the key off and starting the car back immediately temporarily improves it.

Temp sensor, tps, and knock sensor are on the way. I will update again once I start changing those out. Knock sensor will go in last obviously...

 

If you want to check the CMPS for functionality for fuel injection, dismount it from the engine with the harness still connected to it. turn ignition to on position engine off. Manually turn the shaft of the sensor and you should hear each injectors click.

My auto 93 SE intermittently shuts off on me while driving just a month ago. It was a fuel problem. Pulled out the fuel pump, and the wire soldering is loose. Resoldered them and they're working fine to date

 

Let me know if the sensor is no good.

 

Do you have an extra cps?

 

The bad thing about these cars is the ECU is almost no help at all. You will feel like you are chasing lost causes.

I know you replaced 3 coil packs, but I would suggest replacing all 6 with known good ones. At the very least borrow some from a member that has extras just to see what happens.

A long time ago I had an intermittent stalling/bucking problem. It was one of the rear coil packs. MrGone and I spent much of an afternoon swapping all kinds of things -- cam sensor, tps, ECU, igniter...I had replaced the "cracked" coils, but those were all fronts.

Something a Nissan tech once told me is that Bosch spark plugs can zap the coils, too. He told me to run nothing but NGK. I can't remember what was in my car when I bought it, but I think they were Bosch or Splitfires or something weird. I don't know if that contributed to the problem, but I put in NGK and have used only those ever since.

The strange thing about your symptoms is the "holding the car back." I did not have this problem. The car would run OK, then die or buck, especially under load (accelerating or taking off). Really sluggish sounds more like clogged cat or exhaust, maybe even fuel pump issues or clogged fuel filter.

I think I have a cam sensor laying around somewhere. Maybe other parts you can try if you want. Let me know via PM what you are looking for and I can see what I have in the garage.

 

Thanks cliff, I've been thinking about the catalytic converter all day today... If I have time in the morning I'm going to take the exhaust loose from it and see what happens.

I can't rule out the possiblity of a compound problem. This car sat for a long time before I bought it so who knows what could have become faulty in that time period. One bad injector and three bad coil packs have already been changed, with these other symptoms still presenting themselves, there may be multiple culprits.

Btw, tps came today, installed and no change.

 

That and more.

 

It's your knock sensor.

 

Exhaust is fine, I drove around with it unhooked and no change. However, I did find the fuel filter to be clogged, and poured some nasty rusty crap out of it. Put the new filter in and it drove much better, no more feeling like something is holding it back.

Still exhibiting the other symptoms pretty quickly on the drive though. Down to just the sudden loss of throttle and the bucking. So I either had a compound problem or my fuel system is full of crud. Not ruling out knock sensor or something else, but will definitely be pulling the fuel pump out and inspecting the tank as my next step.

 

Fuel tank and pump are rusty and the gas in it is brown. I've already bought a replacement tank but does anyone have the pump assembly? I can order a new pump and strainer, but need the rest of it...