strange power loss

ok, found some info on cps, tps, map, etc... but i'm not sure it fits this situation... maybe map or o2, i'll have to check into those...

here's the deal... normal commute to work 40 miles, sitting at light at exit as we start to move and make turn in 3rd gear the engine loses all power like the throttle cable snapped... i thought i took the turn too slow for 3rd and shift down to 2nd and all is well... engine never died... 10 minutes later after exiting highway and turning again similar thing happens but while in 2nd... sudden loss of engine power for maybe 2-3 seconds then back to normal...

drive home was uneventful... my original thought was fuel filter but i've since knixed that as i don't feel the pump is malfunctioning...

2001 5speed... 200,000 miles

thanks!

200,000 on a 2001. Good deal. Well, soon some one is going to tell me that I sound like a broken record but after reading your post I will give my opinion. I see a lot of people post about various performance or driveability problems. The number one thing that I would do is check the fuel pump. The fuel system can be checked out by installing a gauge on the schrader valve. The pressure on the 2000 model (I have 2000 xj) is 49psi plus or minus 5. So the fuel pressure should be 44 to 54. When turned off the pressure should hold for 5 minutes. To check the volume they say take the fuel line off. I have done it by removing the schrader valve. This seems to let it flow good. It should flow a quarter liter in 7 seconds. Don't run the pump for more then 7 seconds or the fuel pump well may empty. This would let the pump run dry. I have seen others say that they should pump 1 liter in 1 minute. When I have time I will research this more. Another thing that I have seen electric pumps do is run worse at idle then at higher throttle. It would seem that if there was a pump problem it would not supply the engine at higher speeds. Someone else may have more experience or knowledge about that. Do some searching on the fuel issue.

I had similar issues, and replaced the fuel pump, and seemingly fixed it. However, the fuel pump was making a wicked electric buzzing noise too.

yeah i've replaced a bad pump in an older xj, really noisy, seemed to be straining to do it's job... the lack of those symptoms is why i didn't feel the pump to be the culprit... the fact it happened at slow speeds as well (i thought as you did needsrepair, bad=worse at speed)

however, i will take a gauge and check the pressure to be sure... and i suppose after 200,000 miles the pump may be tired...

thanks so far!

I had a similar problem on a non-Jeep several years ago that turned out to be a plugged cat.

interesting about the cat... something like that i would think may throw a code but i have no engine service light or codes (checked)...

now i'm wondering if the transmission may have slipped... this morning i noticed a very slight power loss while accelerating up to speed... just the slightest notion of power loss... now i would think even that little of slippage would cause a noticeable increase in rpm's but no there too...

Check your cps wire isn't hitting the manifold.

had a plugged cat same deal... mil lamp woould come on for o2 after a long while of driving cuz of heat buildup

old_man said:

Check your cps wire isn't hitting the manifold.

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i'll give that a look during lunch today... haven't had the power loss since the other day...

It sounds from your post that it only did that while turning.

I think I read somewhere that 2000 & 2001 XJs have a problem with one of the baffles in the gas tank coming loose, allowing the gas to slosh around more. That could starve your fuel pump for a few seconds while in a turn. Try to repeat the problem by accelerating through turns in both directions.

Also ... how full is your tank? If it's half full or less, that would definitely contribute to the problem. Fill the tank, and repeat the turning tests. If it stalls while turning with a half-full tank, but doesn't do it with a full tank, I'd say it's your gas tank baffles.

If it is the cat a code will pop up soon sence on odb II there is a o2 before and after the cat.

Only In A Jeep XJ said:

If it is the cat a code will pop up soon sence on odb II there is a o2 before and after the cat.

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my thoughts exactly... no codes yet so i'm thinking not cat...

montanaman said:

It sounds from your post that it only did that while turning.

I think I read somewhere that 2000 & 2001 XJs have a problem with one of the baffles in the gas tank coming loose, allowing the gas to slosh around more. That could starve your fuel pump for a few seconds while in a turn. Try to repeat the problem by accelerating through turns in both directions.

Also ... how full is your tank? If it's half full or less, that would definitely contribute to the problem. Fill the tank, and repeat the turning tests. If it stalls while turning with a half-full tank, but doesn't do it with a full tank, I'd say it's your gas tank baffles.

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at the time my tank was a little under half... where i'm at now and i'm trying to get the gas to slosh around, so far i can't replicate the issue...

actually the power loss happened just prior to turning the first time and a good 150 feet after the run the 2nd time...

i appreciate the all the help so far... sooner or later something will set this straight...

ok... finally got the power loss again... same place as original, just as i started a left turn that has a slight incline... took it a little faster than normal and lost power momentarily... plus i only have about 1/8th of a tank of gas left...

looks like the baffle thing may be the reason... i've taken the same turn since last week with a full tank but only now with a nearly empty tank can i get it to lose power...

time to research the baffle thing... thanks for the help my xj brothers!

rokclimbertx said:

ok... finally got the power loss again... same place as original, just as i started a left turn that has a slight incline... took it a little faster than normal and lost power momentarily... plus i only have about 1/8th of a tank of gas left...

looks like the baffle thing may be the reason... i've taken the same turn since last week with a full tank but only now with a nearly empty tank can i get it to lose power...

time to research the baffle thing... thanks for the help my xj brothers!

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I'm almost certain that this is your issue. It's not just 2000 and 2001 models, ALL 97+ XJ's suffer from this problem, and I believe only the 97's were recalled for it at one point....even though the 98-01's have the same parts, same design, and sadly, the same problem.

I've had this happen on my 99 shortly after I bought it. I was pulling out into an intersection turning left and it crapped out in the middle of the turn. Not a good situation when you have a semi coming towards you, and your Jeep is stalled in the middle of the road. I've since learned about where the "sweet spot" is while making turns, and about when (according to my gas guage) I should begin to take it easy.

I've got this problem with my 96 xj. It kind of works for me though, since my fuel gauge doesn't work, I have an indicator of when I should re fuel. Haha:wierd::wierd: