[ash81192]

Hi there,

I've recently purchased a Suzuki Sierra and it was great for the first month and then all of a sudden it started running "rough". All i remember was i was pulling into a parking lot, going down gears and then I took my foot off the clutch and it stalled. the rest of that day it was struggling to idle, when it did idle it was only around 200rpm and almost every time I pulled up at an intersection it stalled. Also now when I go down gears it backfires a LOT. Its been about a month since this started happening and I've noticed its using roughly 16L/100km. I though it was the carby so I swapped it with a refurbished one my mate had... No difference. I've tried a few other thing to get it running right but to no success.

Can someone please help, I love this Sierra but at the moment I've almost given up on it.

[HarryHoudini]

Timing,cam belt jumped a tooth or something similar? Neighbour has a similar problem,except for the backfire, and it turned out to be contaminated fuel.

[ash81192]

That was one of my first thoughts. Took the timing cover off and all seems to be fine. The belt is in good nick and all the marks line up

[Santos]

Compression check and do have access to a vacuum gauge? Also a multimeter?

Air filter clogged? leaks in the vacuum hoses? When you have it running do you have little blue electric worms dancing on your engine?

[ash81192]

I checked the compression
Cylinder 1 = 170psi
Cylinder 2 = 175psi
Cylinder 3 = 165psi
Cylinder 4 = 160psi

The air filter is brand new. What vaccum hoses should I be paying attention to because there is a birds nest of hoses and yes I do have a multimeter

[Santos]

ash81192 wrote:

I checked the compression
The air filter is brand new. What vaccum hoses should I be paying attention to because there is a birds nest of hoses and yes I do have a multimeter

The short answer?? all of them. If they are sucking air after the carb then you have a problem.
Also make sure the choke is engaging when it warms up.

Download the service manual from http://suzukiinfo.com/
It will have the info to check the carb is right, how to test your electrics with a multimeter and set the timing.

[ash81192]

But how does that explain the backfiring?

[Santos]

ash81192 wrote:

But how does that explain the backfiring?

It might not, but making sure everything is as its is supposed to be rather than assuming its right might help find the problem.

[kuta]

I know you have swapped the carby but is sounds exactly like what mine was doing. i would check that you have all vac lines in the correct place or get the shits with it like i did and try a corolla carby (ke55) best thing i have dun so far

[Santos]

kuta wrote:

I know you have swapped the carby but is sounds exactly like what mine was doing. i would check that you have all vac lines in the correct place or get the shits with it like i did and try a corolla carby (ke55) best thing i have dun so far

do you know what size jets are in the corolla carb?

[ash81192]

Yeah It was doing it with my old carby too. To be honest it was running slightly better with the old carby on there.

[kuta]

Santos wrote:

kuta wrote:

I know you have swapped the carby but is sounds exactly like what mine was doing. i would check that you have all vac lines in the correct place or get the shits with it like i did and try a corolla carby (ke55) best thing i have dun so far

do you know what size jets are in the corolla carb?

99percent its 28/28 and think sierra one is 26/30 so over all the same just less shit on it and the manual choke is a nice little bonus with them

[kuta]

have you checked dizzy cap? could be corroded. is it firing on all 4?

[ash81192]

kuta wrote:

have you checked dizzy cap? could be corroded. is it firing on all 4?

It dosnt sound like its running on all four at some moments. And I did check the cap, there is about 50% left on the four points. Another thing to add, it gets works after the engine as normal running temperature. So first thing in the morning when it's still cold it runs fine but as soon as the temp gauge starts to move that's when the problems start

[KEENSY85]

Have u fourced it to back fire through the carb?

[kuta]

i would be thinking vac lines, blocked jet/s or the choke then if its not one of them well would not have a clue
post it up if you work out what the prop is as the answer would of saved me putting the corolla carby on and im betting it will help others

[ash81192]

KEENSY85 wrote:

Have u fourced it to back fire through the carb?

How would that have happened?

[KEENSY85]

You make it happen by swapping leads around, it back fires through the carb and cleans it out a bit