Is it the fuel pump?

1314 Views 23 Replies 5 Participants Last post by jamal, Nov 1, 2008

jamal

Discussion Starter · Oct 5, 2008

I'm totally new here (1st day) so not sure if this is right place to ask....but:

I've got a 93 LS that just has no pep like when I first got it. (I'm a novice in mechanics but wanting to learn.)

My guess is that it's the fuel pump. I drove the car alot on a very low-tank. When I first got the car it kicked up pretty easily past 130 but now it really struggles to push past 90. Above 5000 rpms it seems to have no gumption at all. It seems like if it could only get more guess, but maybe I'm mistaken.

Also, I need to probably put in a new oxy-sensor and need to replace d.cap. and rotor but the plugs and wires are o.k. I think.

Thanks for the help.

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Chefsp0t

· #2 · Oct 5, 2008 (Edited)

Start with the basics. Get a new air filter, use fuel injector cleaner/octane booster for a few tanks of gas (my beater car went from 21 to 25mpg with just one bottle), then install new spark plugs, wires, and a distributor cap and rotor. After that, maybe an oil change and fresh fluids.

An O2 sensor would make it run like hell, not just be slower.

jamal

Discussion Starter · #3 · Oct 6, 2008

Thanks for the input.

I cleaned and conditioned the K&N Filter.

Put in a new fuel filter. New plugs. Tested 4 of the 6 wires for resistance. They seem to be fine.

Dist. Cap and Rotor are on order. There was some oxidation around the rotor, but not extreme.

The rotor looks really pitted. Can anyone tell me what that black coating is for on the tip? Alot of it has worn off.

Well, it does sort of run like hell compared to what it should normally. It doesn't sound too bad, just doesn't have the power at high rpms and can't get up to much more than 90.

So I'm still guessing if the cap and rotor don't help, then it is the fuel pump but maybe the old timing belt stretches excessively at high rpms...need to do that too. Anyone have input on timing belt and performance symptoms.

I guess I need to find out what the codes are on the check engine signal. Anyone have advice on buying a code reader? I guess it's a necessary investment if you're serious about working on your car.

Thanks.

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jamal

Discussion Starter · #4 · Oct 6, 2008

I put in a bottle of STP injector cleaner also. Don't think it helped whatever the underlying problem is.

93fourslapper

· #5 · Oct 6, 2008

don't use the stp injector cleaner, it's junk. It probably won't help at this point, but berrymans or seafoam work alot better. Also i have heard of problems like this with a plugged cat. that'd probably throw a code tho

jamal

Discussion Starter · #6 · Oct 6, 2008

OK, I checked the codes:

16 17 23 24

So it looks like it needs new oxygen sensors. (There are two, right?)

And maybe an EGR sensor, too, needs replacing.

Are these very difficult jobs to do? (hope not)
:shrug:

Thanks also for the injector cleaner tip.

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mx6ReMiX

· #7 · Oct 7, 2008

o2 sensors aren't too hard, the front one is a breeze and the rear one you might have to remove the crossmember. me and my friend replaced it without removing it but it took quite a bit longer than it should just because there's barely any clearance to turn a wrench back there.

bmxfuel007

· #8 · Oct 8, 2008

code 16 usually means you'll need to clean the egr valve, which is a pain to get off. go from the bottom of the car because it's connected to the rear header and head. from the top, you'll have to take the TB and IM off and even then, you'll have no room

jamal

Discussion Starter · #9 · Oct 9, 2008

Thanks for the help, guys.

I'm assuming the two O2 sensors I need are identical. Is that right?

jamal

Discussion Starter · #10 · Oct 10, 2008

So do you guys think the loss of power is due to the sensor failures or is the fuel pump still a good possibility?

I can't figure out which two oxygen sensors to get. Both are before the the catalytic converter right? One is on the exhaust manifold and the other one farther down on the pipe, I think.

I've got a new d.cap and rotor now which seems to be an improvement generally speaking but pushing past 100 mph seems to be a no go still. The car seems to have decent power up to about 70, but after that it's quite reluctant to accelerate.

bmxfuel007

· #11 · Oct 10, 2008

maybe it's a sign to stay under 100

jamal said:
So do you guys think the loss of power is due to the sensor failures or is the fuel pump still a good possibility?

I can't figure out which two oxygen sensors to get. Both are before the the catalytic converter right? One is on the exhaust manifold and the other one farther down on the pipe, I think.

I've got a new d.cap and rotor now which seems to be an improvement generally speaking but pushing past 100 mph seems to be a no go still. The car seems to have decent power up to about 70, but after that it's quite reluctant to accelerate.

jamal

Discussion Starter · #12 · Oct 10, 2008

under 100???? hah!

I don't often drive fast but come on.

OK another theory...maybe driving such a long time with failed O2 sensors caused the Cat. Converter to plug up and that's part of why the engine is not delivering normal maximum power output.

Does that seem more likely than the fuel pump?

93fourslapper

· #13 · Oct 10, 2008

if the o2s were bad that could def cause the cat to get screwed up, thats why I mentioned it

bmxfuel007

· #14 · Oct 10, 2008

i know when i drove a honda accord that had its cat messed up, it would even struggle to get up to 70mph and really poor gas mileage. i would just replace the o2 sensors and cat

jamal

Discussion Starter · #15 · Oct 11, 2008

Is there any one cat converter that is just heads and shoulders above all others?

I guess it's not necessarily a limiting factor as long as it's a high-flow unit.

Trying to figure out which to buy now.

Thanks guys.

jamal

Discussion Starter · #16 · Oct 12, 2008

Can I get away with simply removing the two oxygen sensors as a short-term fix for a plugged catalytic converter?

Is that fairly safe? Hope so.

bmxfuel007

· #17 · Oct 12, 2008

just get a magnaflow high flo cat or something. i know someone found one that was an exact fit for our car for around 120 bucks or so. might have been less than that

jamal

Discussion Starter · #18 · Oct 12, 2008

OK this is what I"m ordering for Monday unless someone tells me otherwise.

MagnaFlow 23693 Direct Fit Catalytic Converter
Amazon.com: MagnaFlow 23693 Direct Fit Catalytic Converter: Automotive

List price is $118, I guess. Is this a good one to go with? Or something else.

93fourslapper

· #19 · Oct 13, 2008

I personally like the magnaflow products, but any good name should do well for you

93fourslapper

· #20 · Oct 13, 2008

check the magnaflow website for authorized dealers. most have free shipping

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