[albie200]

Hey guys, I got a 93 Sierra with single point injection standard 1300.

Was driving it the other day and I noticed a change in exhaust note, then it was way down on power as in only just getting to 70km, it's only revving out to 5500 rpm and then just hunts between 5500 and 5000 foot flat..
it does seem to be idling a bit lower than normal but other than that it's fine... Does sound like a rotary when cold though..

I took it for a small drive today and I can only get 50km out of it now..

I did change the water pump the other day,I'm wondering if the cambelt has jumped a tooth..
It was fine for a couple of days after I changed the pump before this happened though..

Other things.. Could it be fuel starvation?

Any help would be great.. Thanks

[303zuke]

93 Sierras will have Carbs, not injection. If it's a 93 Samurai, it might be injected. We never got Efi on Leaf sprung Sierras in Aust, so any experience with that system here will be non existant.

You could check the timing with a timing light. One tooth on the cam belt pulley will equal about 8 degrees of timing out, and it will probably still run. One tooth on the crank pulley will be about 16 degrees, and I doubt that would allow it to run.

Failing that, do a compression test on each cylinder to see if you've dropped a valve. Running on 3 cylinders will sound like a rotary at idle.

[albie200]

303zuke wrote:

93 Sierras will have Carbs, not injection. If it's a 93 Samurai, it might be injected. We never got Efi on Leaf sprung Sierras in Aust, so any experience with that system here will be non existant.

You could check the timing with a timing light. One tooth on the cam belt pulley will equal about 8 degrees of timing out, and it will probably still run. One tooth on the crank pulley will be about 16 degrees, and I doubt that would allow it to run.

Failing that, do a compression test on each cylinder to see if you've dropped a valve. Running on 3 cylinders will sound like a rotary at idle.

Yeh it's a samurai. Just said it was a Sierra for you guys.. well it's actually a jimny,got a/c,power steer and efi front standard.. Imported from jap land.. JDM...

I'll grab one and check it out..
It's still running on four cylinders as when it's warm it idles fine.. About 600 rpm it use ti idle around 750..

[whincup]

didnt someone have the same issue where it slowly got worse and worse? turned out to be a fucked cat converter on the exhaust... undo the extractors and try revving it then, 10 seconds to rule that out

[albie200]

whincup wrote:

didnt someone have the same issue where it slowly got worse and worse? turned out to be a fucked cat converter on the exhaust... undo the extractors and try revving it then, 10 seconds to rule that out

Forgot to mention.. It's got a 2" straight thru.. I will try that though..thanks