Hey guys i haves some simple questions from a noob diy car guy.

I have a 88' GXL that the motor runs great. I bought the car from an acquaintence who had the engine rebuilt at ~100,000. The car now has 230,000. The rebuild was done at atkins rotary some years ago.

I have the racing beat cat back kit but the cats are original i think. I think they have become plugged as they become very noisy (they've always rattled) and the exaust pitch sounds really dirty.

My car runs like absolute *** now, is this because of cats? I have ordered the bonez presilencer and cat replacement but dont know how long till i get that. This just started happening today with the really poor performance, however they have sounded bad for a while.

2nd question
When i bought the car it leaked some oil and stunk like burning oil from the engine compartment when driven hard. I traced the problem to a broken line on the MOP. I used these forums for reference and removed the MOP and have been premixing.

I'm worried that this problem was left un-repaired for quite a while. I did a compression test as explained in the haynes manual and got 115 and 110, with no big bounces below 35 on either rotor. Am i safe?

Thanks for reading.

 

I would drop it and gut it. My RX-7 had a clogged cat and the rear rotor with no compression. Mazda mechanic told me that the cat killed the motor, when we called them while we were fixing it. Nobody here has been able to confirm or deny this (to me). But just to be safe (and cheap) I would gut it.

 

115 and 100 for a rebuild with 130,000 miles on it is pretty incredible. Keep premixing and gut that cat. All should be well.

 

I don't understand your compression results. You should be getting 3 readings for each rotor for a total of 6 compression numbers. You have 2.

 

maybe that is the average from the front and rear rotor.

 

That was the totals on each rotor with the check valve closed. 115 110
With the check valve open it bounced quickly around 35psi each.
I didnt see it dip below 30 at all.

I have the bonez system on the way i just wont drive it if its hard on the motor. Dont feel like doing the work of gutting old cat if replacement will be here soon. prime weather for cj5 anyways.