[nigelh]

Hi all,

Just new to the forum - I have been reading through and trying to find if anyone has experienced this problem (not found anything). Got problems with my sierra in that after running for a period of time (30-40 K) the engine starts to surge. Only had it for about 6 months, been running really well until this started, had the alternator sieze up on me and replaced that, replaced the fuel filter and also all the leads. Since the problem started it is also tending to idle high and you need to tap the peddle to get it to drop down.

Around town it doesn't appear to do the surging, but only after being out on the highway.

Any help and suggestion greatly appreciated

[Scrawny]

I'm guessing it's just the standard 1.3 motor? When it starts surging, does it die or just like a slight miss? Is it constant when it does it?

[TryHard]

when u replaced the Fuel Filter how dirty was it .. is posable that your carby is blocked up.. after i changed my fuel filter i had same prob for a little bit i warmed engine up took it out revved the crap out of it and problem solved ..

[JrZook]

Possible signs of a failing fuel pump

[nigelh]

Hi Guys,

Thanks for the quick responces - sorry should have stated that it is a 1985 1.3ltr Sierra.

The problem seems to occur after I have driven for about 20-30K and then start to go up hill - starts surging, back off the gas to reduce the fuel and it will stop surging, but if I give it more gas will then start surging to a point where it almost stalls - have to back off the gas again and just sort cross fingers I can get to top of hill without it conking out.

I did run on a couple of tanks of 95 - thats when it started, changed back to 91 but still seems to be a problem.

Thanks
Nigel

[LittleJeep]

sounds like it is not getting enough fuel when driving on the highway, i think the fuel pump may be your problem.

[Scrawny]

Certainly sounds like it's starving for fuel

[nigelh]

Guys,

Thanks for the replies - any way of testing if it is the fuel pump. How easy are they to change and where would be the best place to get a new one.

Thanks

[Teracis]

Sounds like a similar problem to mine!

I'm just not driving on the highway or at full throttle, seems a decent temporary fix until I replace the engine!


Oh and I read a way to test the fuel pump is to put a T in the output that goes to the carby, run a line through into the cab and have it go into a jerry, apparently they pump about 1L more than they need per minute at 3000rpm or something like that, I forget exactly but it's on here.

[Verm1n]

undo the fuel line at the carby and undo it at the fuel pump.. shoot some air through the line 'incase there is Foreign debris' before attaching the line back to the fuel pump... try starting the car to ensure fuel is coming out the pump nice.. reattach the fuel line to the pump start it again to see if it comes out at the carby.. attach fuel hose to carbie

I had fuel probs - foreign debris

[SuziBlu]

Id change the fuel filter first, cheap as, and if its not the prob, well you have eliminated one cause, and have a fresh fuel filter.

I had a bugger of a time with mine, then found that there is a fuel filter (clogged as all get out) next to the tank, hooked onto the chassis

[TasRat]

Hi
Next time you have trouble with lack of power at highway speeds and especially up hill, stop and try to remove the fuel filler cap. If its hard to remove could be a build up of vacuum in the tank.
Caused by a blocked carbon canister in engine bay. clear the breather on the base of the canister.

Don't laugh it happens.

Cheers

[Teracis]

TasRat wrote:

Hi
Next time you have trouble with lack of power at highway speeds and especially up hill, stop and try to remove the fuel filler cap. If its hard to remove could be a build up of vacuum in the tank.
Caused by a blocked carbon canister in engine bay. clear the breather on the base of the canister.

Don't laugh it happens.

Cheers

Good idea, I was about to post that I'll try it, but then I remembered I'm sure it's the carby because it doesn't do it when we put anto86's carby on my zook!

[steak_knife]

SuziBlu wrote:

Id change the fuel filter first, cheap as, and if its not the prob, well you have eliminated one cause, and have a fresh fuel filter.

I had a bugger of a time with mine, then found that there is a fuel filter (clogged as all get out) next to the tank, hooked onto the chassis

I have to agree....

[nigelh]

Changed the filter near the tank .. Is there a second filter? Anyone know how hard it is to change the fuel pump? Is there any setup required? Thought that if it was simple enough I would just replace it

[JrZook]

SuziBlu wrote:

Id change the fuel filter first, cheap as, and if its not the prob, well you have eliminated one cause, and have a fresh fuel filter.

I had a bugger of a time with mine, then found that there is a fuel filter (clogged as all get out) next to the tank, hooked onto the chassis

Well in his first post he has changed the fuel filter already, but shitty fuel could be a valid point also

[JrZook]

nigelh wrote:

Changed the filter near the tank .. Is there a second filter? Anyone know how hard it is to change the fuel pump? Is there any setup required? Thought that if it was simple enough I would just replace it

May as well replace it if she looking pretty worse for wear. Should only have an inlet and outlet barbs for teh fuel lines and 2 bolts holding it to the block. Watch out when you take it off as it will leak a bit of oil from the head and also make sure the pin the drives the pump doesnt fall outta the head.

[SuziBlu]

JrZook wrote:

SuziBlu wrote:

Id change the fuel filter first, cheap as, and if its not the prob, well you have eliminated one cause, and have a fresh fuel filter.

I had a bugger of a time with mine, then found that there is a fuel filter (clogged as all get out) next to the tank, hooked onto the chassis

Well in his first post he has changed the fuel filter already, but shitty fuel could be a valid point also

I put the second bit in, as like I said, I changed my fuel filter, the one right next to the carby, it was pretty chat, and made a bit of difference, but, still nothing to write home to mum about.

Took me ages to realize there was still a stupid filter by the fuel tank.

There is no filter by the fuel tank now.

[JrZook]

SuziBlu wrote:

JrZook wrote:

SuziBlu wrote:

Id change the fuel filter first, cheap as, and if its not the prob, well you have eliminated one cause, and have a fresh fuel filter.

I had a bugger of a time with mine, then found that there is a fuel filter (clogged as all get out) next to the tank, hooked onto the chassis

Well in his first post he has changed the fuel filter already, but shitty fuel could be a valid point also

I put the second bit in, as like I said, I changed my fuel filter, the one right next to the carby, it was pretty chat, and made a bit of difference, but, still nothing to write home to mum about.

Took me ages to realize there was still a stupid filter by the fuel tank.

There is no filter by the fuel tank now.

So any junk in the tank goes thru the fuel pump first?

[SuziBlu]

yep, cleaned the tank, so it should be fine. If the pump stuffs up, it will be my fault, an Ill deal with it then.