I have a 2000 manual WS6 with about 85,000 miles.

Every time I drive it, randomly it seems like the engine is cutting out or briefly losing fuel. Can't really think of any other way to describe it. It's like you are going along normally then all of a sudden it just kind of sputters and recovers again right after. It can do this once every 30 seconds or so or multiple times back to back in just a few seconds. Sometimes it's slight and other times it's super rough like the car is about to die before it recovers.

This happens at random speeds and seems to be any gear. It does not do this during idle. It can idle forever and seem fine.

I'm still very new to mechanics so I don't know a lot about repair yet. I'm down to try / learn anything though. After reading quite a lot of things on the forums I found a few issues that were close but not exactly the same.

I suspected it could possibly be the MAF and cleaned it with MAF cleaner. Seemed to have no change. I also tried running the car with it unplugged. It almost seemed like it was doing it more with it unplugged than when it was plugged in.

Any suggestions would be really appreciated!

 

Check O2 sensors and spark plugs

 

you can go through a lot to figure this out.. i had this issue because of the regulator... replaced the whole fuel pump assembly and the pump .. tuned it .. now its fine.

but it could be O2's , Spark Plugs, Injectors.

 

Thank you guys for the info. I will start with those things and go from there.

 

If you don't want to just buy parts and hope you find the problem.....get someone to scan it. Tell them to specifically check the how the 02 sensors are switching. Make sure it's someone who knows what they are doing with the scanner and can read the numbers properly. A speed shop is best for this.

Ae you using a lot more gas than usual? Do you smell gas?

It's most likely an 02 sensor.....but unfortunately it can be 1 million other things......

.

 

I am borrowing a scanner tonight and am going to scan to see if I'm getting any codes. I'll see if there are any good shops in the area to do a more detailed check if possible.

Gas use I'm not real sure as that's another problem I'm going to have to tackle this summer Gas gauge does not read properly. Every now and then it will come up to around half a tank but most of the time it's pegged on the E. I believe that may be a separate issue with the float or somthing? If it's related maybe I can tackle two things at once and resolve both issues.

I would say it smells just a little more rich than normal but not too bad.

I guess worst case scenario I spend a bit more money than I wanted to, learn a lot and have some spare parts on hand!

 

I asked about the gas smell because when the 02 sensor(s) are failing you will run rich and smell gas....and gas mileage goes noticeably to hell.

See if they are switching properly while the engine is hot and running....with an OBDII scanner.

.

 

1st thing I would check is the connectors at the PCM for corroding and replace the ignition relay. Another thing you can try is find the nastiest bumpy road and take it for a drive, see if its bump related.

 

If it does this before the car gets to operating temp then the O2 sensors prolly aren’t the culprit. Post what codes you find, that may shed some light. Any recent mods or replacements?

 

Sounds fuel related to me.

I would:

1) Replace the fuel filter if it's been more than 15k since it was last done.

2) Go to autozone and rent a fuel pressure guage and see what the pressure actually is while driving.

 

I scanned it last night and got 3 codes.

P1635

P1639

P0102

I did a bit of research on these codes last night and found that P0102 is often related to the MAF. Confused by this as it does the same thing when the MAF is unplugged completely. I suppose it's possible that it's not functioning right at all even when it's plugged in making it seem to not have any effect when unplugged.

Also am getting the impression this may be electrical/fuse or PCM related? So many things it could be but at least codes may help a bit. Can start there since there are some.

Am going to check the fuses here in just a few to see what I come up with there. I really hope it's that easy but I doubt it.

No mods to the car really except a lid and replaced a busted factory clutch with a ZOOM from Advance. This problem started well after replacing the lid and clutch though.

I will test everything you all have suggested but I'm like REALLY new to car mechanics so it may take me some time to figure out the specifics of things that seem easy lol.

Thanks again for all the replies and help. I will keep you updated as I check things out!

 

I may try to get started on plugs and wires tomorrow. Never done it before. Driver side doesn't look terribly difficult. Passenger side may be another story. I got time since the car isn't a daily driver so I'll figure it out eventually. Pretty good write up on installuniversity.

What plugs do you or anyone else suggest as stock replacements? Should I bother with replacing wires too or just leave them stock?

I did find this about testing O2 sensors provided I can find the ones in the engine bay and get them removed.

Is this a legit way to test them?

 

I figure I'll probably do the pump last. I know that's a pretty large job with dropping the tank and everything. I also need to figure out what's up with the float so will probably do both together when the weather gets a bit better. Might also need to get some help with that one.


Spark plugs should be coming soon. I'm looking now for info on injectors. Can you give me any addtional info about them? I literally know nothing except what I'm finding on the internets. How hard / expensive are these to replace? What's the difference with stock and performance injectors?

Sorry for n00b questions lol

 

You may have set this code when you ran the engine with the MAF sensor unplugged, so don't get too hung up on it as the cause. Reset the codes and see what comes back up.

 

You were right about the codes. I cleared out all three and ended up without the P0102. That one is gone now.

Now all I have is the P1635 and P 1639. Also drove the car a little ways to see if it would throw any other codes again. Still just those two codes.

Something else I did notice on the last drive was that the lights go out kind of like the whole car is losing power when this happens. Guess I never really noticed much since prior test drives were generally during the day.

Do any of these symtoms sound like this could be some type of grounding issue?

I know PCM was also suggested. There any good way to check / test the PCM? have some TR55 plugs on order so hopefully those are going to get in there real soon.

 

I would REALLY look all over at the cars grounds! I would do nothing prior to that. No money or parts. All the symptoms can be due to a bad ground. Take all the ground wires and straps off, clean them REALLY well and reinstall. Some may even look bad. If you have a bad ground at one end of a fine wired, it can cause the wire to deteriorate and actually lose capacity. If you have an old battery it may be time to get a new one.

On these cars, where the electrical system is so integral to it's proper operation, we often overlook the simple things

 

Most definitely an electrical issue... Damn. You're going to have so much fun :p

 

Do any of you have any idea how many grounds there are and if any are kind of hidden? I know I've seen at least 3 or 4 under there not looking real hard. Wasn't sure if there are any others have found that were harder to find.

Can a battery going bad actually cause this before seeing other symptoms of it needing replaced?

Is there any specific type or kind of battery that you guys recommend for replacement or does it really matter?

Also what are the torque specifications for on the PCM? I saw when I was looking last night that it is actually labeled with the specs right on the plastic beside the bolts holding it in. I know sometimes it's extremely critical to get things exact wtih torque and other times it's really not that critical.

Just want to be careful taking stuff like that out since i'm pretty newb with most of this stuff.

 

So I replaced the battery with a new one. Auto-craft Gold battery from Advance Autoparts. When I had the old one out I cleaned about 5 grounds that I could get to.

Main battery ground, one right in front of the radiator cap, one in front of the fuse box, one behind the fuse box and one underneath near the alternator with a braid ground attached as well.

Cleaned them all real good with a wire brush and dusted them off. Everything looked a lot better. I know there are more but I have no idea how to get to them.

I started the car up and it ran a lot worse than it ever has. It sounded and felt terrible like it was going to die any second. Stumbling like crazy. Smelled pretty strong too but wasn't a gas smell. Same thing when giving it some gas in neutral it just stumbled like hell and then felt like it was going to die when you come off the gas.

It did die after giving it some gas a few times. When I tried to start it after it died, it wouldn't start. Turned over fine but acted like it was out of gas. Gave it some pretty good gas while trying to start it and then it finally started rough. Ran a little better than the time before but not much. Turned it off again and started it again. Seemed somehow better this time. No idea what would all of a sudden have changed. Then it idled fine for about 10 min before i cussed it and turned it off.

I know for sure I didn't move or unplug or bump anything else when working on the grounds. I was very careful. The only thing that might have happened is something with the ground on the back of the driver's side head. I was able to get my hand on that one slightly but that's about it. I didn't pull it or anything just felt the wire and the bolt and that' it.

Still a lot to try that was suggested above but if anyone has any addtional input or ideas based on my latest findings please let me know!

 

you dicked with the grounds and caused a change. That's actually good news, because now you have a cause and effect.

TAKE YOUR TIME and trace out all of the grounds. Also, unplug the MAF until you get her started and running half-assed. Takes that out of the equation for now.
02 sensors will NOT cause a start up issue. The car runs in open loop until it hits a set temperature. Check the plugs, and check fuel pressure. Pretty much any shop will have a pressure gauge that will screw into the Schrader valve on your driver's side fuel rail... or you can make an adapter for pretty cheap. It's a 37 degree hydraulic fitting, can't remember the size. AC or refrigeration parts stores have it.