'87 LeSabre - absolutely horrible milage

[stuzman]

Originally Posted by highlandlake

Might be a longshot - but do you have a brake caliper or wheel cylinder hanging up? Might explain the poor acceleration and lousy mpg. Just a thought. Tom

Have you thought about putting a scanner on it and monitoring some of your sensors such as the MAF, ECT, IAT and fuel trim readings to get an idea of how well the engine is running?

[LeSabre97mint]

Originally Posted by TrueLyFE

What does this involve, where could I get it done / what would I need to do it?

You will need a compression gauge. You can get one at any good autoparts store. You will need to remove all sparkplugs.

Do a search on Google for Compression test.

If your Aunt put an engine in your car she can do a compression test.

I also like Toms suggestion of a brake hanging up.

Regards

Dan

[auto trainy]

when you say crate engine,is this the same engine that was in the car and not altered (racing or larger or high performance)?

[TrueLyFE]

Originally Posted by auto trainy

when you say crate engine,is this the same engine that was in the car and not altered (racing or larger or high performance)?

No. It was a new in crate and built at a place in town (my aunt was going to rebuild mine, but my uncle was impatient and now he expects me to pay him off for doing it on his own..sigh, luckily we got a decent deal on it). A few things were pulled off of the old engine, like the injectors, and those were new. It's still the same size and type of engine.

[LeSabre97mint]

Originally Posted by TrueLyFE

No. It was a new in crate and built at a place in town (my aunt was going to rebuild mine, but my uncle was impatient and now he expects me to pay him off for doing it on his own..sigh, luckily we got a decent deal on it). A few things were pulled off of the old engine, like the injectors, and those were new. It's still the same size and type of engine.

Okay....is it new or rebuilt? New = new block, new pistons, get the idea? Rebuilt is....used items checked...reconditioned where needed...ie...cylinders possibly bored out (to clean up taper and out of round), new pistons. Or rebuilt could be just new rings and bearings. Who put the heads on? Where they torqued correctly? (I'm still thinking about poor compression here. Where you able to do a compression test?)

I am really trying to help you out here.

Regards

Dan

[TrueLyFE]

Again, it is a brand new, new parts, not remanufactured crate motor. The place that I purchased it from put it together after a down payment. Most parts started at 0 miles (I can't think of anything internal to the engine that wasn't new). Also, I did find out that the previous owner was getting 24mpg just before it broke down.

I haven't had time to do a compression test yet, I should on the weekend.

[LeSabre97mint]

Originally Posted by TrueLyFE

Again, it is a brand new, new parts, not remanufactured crate motor. The place that I purchased it from put it together after a down payment. Most parts started at 0 miles (I can't think of anything internal to the engine that wasn't new). Also, I did find out that the previous owner was getting 24mpg just before it broke down.

I haven't had time to do a compression test yet, I should on the weekend.

I realized that you had used the word "new", however, the word new can be defined as: new to you, a different motor, our language can be a bit ambiguous. I replaced my tranny in my 97. I got a used one from the bone yard. Is this my "new" tranny?.....


We all now know that you have a brand new motor.

Dan

[TrueLyFE]

It's okay, I understand

I have also been having a voltage problem - grounds were mentioned when previously brought up on AF and I have checked everything I can, and it all looks clean (removed and reattached many just to be sure). When I accelerate hard enough (usually normal acceleration speed) my voltage drops to ~11.8-12.8v, and sometimes also drops or fluctuates between this and 14.4 when coasting ~40, or >70mph (not on the lower parts of gears) it will be low. Brand new alternator, and battery connections are fine (just checked and reattached minutes ago to be absolutely sure). Don't know how much of a problem this would be on fuel economy, but is something that needs fixed anyway. Any ideas about this?

As I said earlier, I will report on compression sometime this weekend. In a sense I am hoping that is it, because I am getting sick of all these random troubles with this car ;p

[TrueLyFE]

Hey, the plug that goes into my alternator was loose. That's been the voltage problem I have had all this time (I swear I checked it before, hmm....). I was trying to fix one of my other little problems and decided to just check that by pushing down - bam, engine decreases RPMs a little and voltage jumps up (have voltmeter near battery).

Anyway, it is running very nice now - engine doesn't rev up as high when accelerating, and it seems like a much smoother ride. I have a feeling that if this didn't completely fix the milage issue, it will at least be a good portion of it. I filled up my tank and will report MPG in a week or so.

Oh, and time for a new battery :/

[Hapynzap]

So what's the update on your car and the poor mpg? It's normal to get lower mpg during the break in period but yours is somewhat low. Is this all city driving?

Did you re-use the old catalytic converter? It might be plugged up with soot from the old engine.

[TrueLyFE]

Hey,

Most of it is city driving, from my house to work and back or to the store. Lots of stop and little go. Old owner used it for mail delivery though and it still got ~24mpg doing curbside.

Old cat, probably needs to get replaced anyway. Would it be responsible for that high of a drop though?

Right now, I am at about half a tank (3/4 on my gauge) and it is looking like it hasn't improved much. Will post numbers on my next fill-up, as well as compression test pass/fail if it isn't significantly improved (which it is now looking like it isn't )