[stuballs]

Gday guys and gals my name is stu. I am just wondering if someone here can possibly point me in the right direction. I recently brought a 91 suzuki sierra g13b and blew the head gasket. Got it machined and replaced also new water pump, radiator, Rocker cover gasket, plugs, leads, dissy cap, and rotor button. Now my problem is.. Before the head gasket blew i could get her to 110km in 5th, But now it seems 5th gear wont go above 3000rpm with my foot flat. I no the mechanic played around with the carb a bit so this might be the issue but no 100% certain. Also it started to get really hot after a fairly long drive so i needed to pull over. Could this be due to timing? The mechanic said the timing is fine as he got his apprentice to do it..... Thanks in advance and nice to meet you all

[JrZook]

Could be cam timing out by a few teeth.

[FullyZooked]

Could this be due to timing? The mechanic said the timing is fine as he got his apprentice to do it..... Thanks in advance and nice to meet you all[/quote]

Nothing against apprentices but this would concern me. The fact that the mechanic didn't check it himself.

I would check it quickly by setting top dead centre no.1 and checking cam sprocket timing mark. If it is indeed a tooth out you will see it.

[stuballs]

Thanks mate will have it investigated this arvo and report back

[MacDaddy]

stuballs wrote:

Gday guys and gals my name is stu. I am just wondering if someone here can possibly point me in the right direction. I recently brought a 91 suzuki sierra g13b and blew the head gasket. Got it machined and replaced also new water pump, radiator, Rocker cover gasket, plugs, leads, dissy cap, and rotor button. Now my problem is.. Before the head gasket blew i could get her to 110km in 5th, But now it seems 5th gear wont go above 3000rpm with my foot flat. I no the mechanic played around with the carb a bit so this might be the issue but no 100% certain. Also it started to get really hot after a fairly long drive so i needed to pull over. Could this be due to timing? The mechanic said the timing is fine as he got his apprentice to do it..... Thanks in advance and nice to meet you all

Hmmm... Suzuki carbies can be tricky to tune, as they need to be adjusted when cold, and hot... when i had my carby Vitara, i had my Suzuki mechanic tune it, and he had to do 8 week course to do them properly, so i would say your mechanic has stuffed it up and i would check the timing yourself, if you can, as an apprentice doing it, and him not checking it, is a bit iffy... timing is 10degrees BTDC at 800rpm...

[stuballs]

Well it looks if its out i am not going to be happy i paid a sh!t load of money to get this done... Ahh the world of mechanics. Love my car though will post some pics of it this arvo aswell

[Ben_Sierra]

Nnot enough ignition timing could be causing your issues also.

Also, as well as checking the timing at idle, you should be looking at the advance too...

[zooky08]

Had the same problem but only revved out to 2500rpm max
My timming belt slipped cos my timing belt tensioner snapped
Also thought it was a head gasket but end up being a cracked head

[Jasen]

Is it possible the vacuum advance has not been reconnected to the dizzy (or at the manifold)? What's it like in lower gears - does it still rev freely and pull in the higher rev range(in lower gears)?

[stuballs]

Yeah no prob in lower gears will get past 5k rpm. Just 5th it will go 90km on a flat road and just stay there just under 3000rpm

[bohuler]

A bit of a random one but worth checking, look at your air filter. My was doing very similar until i changed the air filter

Dave

[christover1]

4th and 5th are connected to the carby/ pollution control system.
Maybe something got disturbed.

New work can take time to bed in, it may come good by itself.

getting warm isn't too good.

[stuballs]

no extremely worried its ok running round town just after an hour or so even in 5th at 70km/hr was getting hot

[zuk_244]

My Mate bought a sierra and it was doing exactly what you are saying and always ran REALLY hot off road.
When i checked his timing it was set to 0 degrees .

MacBear wrote:

timing is 10degrees BTDC at 800rpm..

My motor use to ping when i had the timing that high (i had my idle set to about 950rpm) . I found 7-8degrees BTC to work well.
While you have the timing light on it rev the motor up abit and the timing should jump by about 6. If it doesnt go up you have trouble with the Vac Advance.

[Ben_Sierra]

zuk_244 wrote:

My Mate bought a sierra and it was doing exactly what you are saying and always ran REALLY hot off road.
When i checked his timing it was set to 0 degrees .

MacBear wrote:

timing is 10degrees BTDC at 800rpm..

My motor use to ping when i had the timing that high (i had my idle set to about 950rpm) . I found 7-8degrees BTC to work well.
While you have the timing light on it rev the motor up abit and the timing should jump by about 6. If it doesnt go up you have trouble with the Vac Advance.

Mine is at 10 but I only run 98RON fuel... If you run 91RON then yea 8ish is probably about right...