Engine Problem?

'91 XJ, '93 4.0L, NV3550, D44 rear, NP231, HP30 front, snorkel, RE62mm TB, 62mm Hesco TB spacer, K&N drop in filter, Dynomax cat back, factory cat, 3.55 gears, etc...

Anyway, my engine sounds louder on hard pulls.. mainly 2k-4.5k or so... It sounds like a big truck.. it's been warm recently so I think it's just 'cause I put the snorkel on when it was cold out and these are the first times I've had the windows down.

Aside from that.. It SEEMS like the Jeep is slower when I have to get on the gas hard. I also tried to just redline it today to see if I could.. and it will make it just before redline.. in 1st gear it's about 300 RPM from redline and 2nd it was 600 RPM from redline... where it tops off and I can't go faster until I shift.... Does this sound normal or is something going on? Should I change out the plugs, wires, cap and rotor (Been about 20k miles I'd say since my last change). Thanks!

Anyone?

Having the snorkel will add a bit of noise. If you turn the head of the snorkel toward the rear you can hear the air being sucked in. All this is normal.
As for it seeming to pull harder the snorkel amy be at play here also. The air has alot further to travle then it did in stock form. Also with the bends that the snorkel tube has this causes a slow down in flow. I have coined this "snorkle lag". The average person would never notice such small things but for us that are really intune with our rigs it does stand out. It is something that you will get use to.

Your red line rpm's seem to be fine IMO. I wouldn't worry about that.

If it has been 20K I would say it is time for a tune up.

It's been doing this just recently.. the noise just got louder maybe during the last month or so. I put the snorkel on back in September. It really seems to be lagging a LOT. First gear is okay, but losing power. Second on up are really lacking. I am checking my K&N filter today and I am replacing the plugs today as well. I'll be checking the cap/rotor for any abnormal wear, etc.

The Jeep is sold, so I don't want to spend much, but I won't sell something to someone that I think has issues.. unless they know what the issues are. Thanks man.

Onkover said:

Having the snorkel will add a bit of noise. If you turn the head of the snorkel toward the rear you can hear the air being sucked in. All this is normal.
As for it seeming to pull harder the snorkel amy be at play here also. The air has alot further to travle then it did in stock form. Also with the bends that the snorkel tube has this causes a slow down in flow. I have coined this "snorkle lag". The average person would never notice such small things but for us that are really intune with our rigs it does stand out. It is something that you will get use to.

Your red line rpm's seem to be fine IMO. I wouldn't worry about that.

If it has been 20K I would say it is time for a tune up.

Click to expand...

The more I drive the more I realize this is not normal. There's definitely something going on here. I'll be changing the plugs, cap and rotor today if I can.. it's butt cold out today and snowing.. wtf.. it was 80* Monday and 75* on Tuesday.. this is ridiculous!!!!