Technical fuel pump!!!

[johntra]

hello again to all the good people on this forum..if you can remember i have the problem with hesitation on my 98 1.6 16v brava...the problem is still there ..anyway i was at the mechanic shop yesterday because i was thinking to go on diagnostics..when i arrived there they ive explained my problem to the mechancics..and then he started to plug computer on my car, but then the other mechanic came on and said that my problem is fuel pump..he concluded that because of the buzzing noise of my pump..yes it is making that noise and it is loudy..you can hear it very well..but it was like that since i bought it..he said that the pump is soon to be dead ..and that she doesnt have the pressure to put the fuel in engine..it could be because the pump is dirty..because our fuel is ****...it was an older mechanic with lot of expirience..so i think that this is logic..ive changed everything on car, filters,spark plugs..ive cleaned lamda sensor, idle valve..and nothing happened..this could be logical because i can sometime smell fuel when im starting the car..i think that pump is dirty..and then i was afraid because i thought the pump is expensive..but than again it is not so expensive it goes about 100 euros in my country..and i will have guarantee on it..so i am asking you because you are people with lot of posts and experience..could this be the problem..i never had any warning lights on dashboard...it hesitate all the time..sometimes less when its warmer, but then it doesnt have the edge in start..i am looking your opinion...thanks

 

[jug]

you should ask them to test the operating fuel pressure before you buy a new pump, i believe the operating pressure in the fuel rail is 2bar but i'm not 100% sure about that, cant remember right now. i know the previous owner of my 1.6 bravo had the fuel pump changed along with many other things, and it was Fiat who suggested a faulty fuel pump, but they were wrong and it made no difference. i can guess you have a faulty injector or coil purely based on the fact that you have a mk1 bravo with 1.6 engine, and it is almost always a faulty injector or coil with these cars. check the coil and injectors before you assume anything else is wrong.

 

[johntra]

jug thanks for answering...i forgot to tell that ive changed the coil pack..i dont know am i telling you the correct word..but that is the thing where spark plug cables are begining..i dont know if that it is correct word...last summer the damn thing went dead and i changed it...but the problem is still here..i dont think it can be injectors because the car runs pretty normal in 4 or 5 gear..and even in third..it only happens in first two gears when the car needs more fuel..and ive put two bottles of fuel injector cleaner..but i will have the guarantee on the pump..if it is not the pump issue i will simply go back and take my old pump and mine money..but i am in big hopes that this could be it..

 

[jug]

a faulty fuel pump will usually cause the car to run fine in all gears below 3000rpm and struggle at higher rpm, if your car is pulling smoothly in 4th gear right up to 6500 rpm then i would be very surprised if the fuel pump is at fault. a faulty fuel pump will cause less pressure to be created in the fuel rail which means the injectors do not release enough petrol at higher rpm to match the air intake, this leans the air/fuel mix and causes a flat spot or hesitation. this effect should be the same in every gear and should be noticable at the same rpm in every gear. if your car really is only having problems in 1st and 2nd gear then im a bit confused as to what it could be. guess its worth trying the pump if you can return it.

 

[Bravicssimo]

Actually what Jug says makes a lot of sense, I too have been investigating a high pitch loud noise that happens when I rev the engine above 5000rpm, this will coincide exactly with the engine starting to shake and misfire.
the noise seems to be coming from the boot area and I assume that could be the Fuel pump. I am not sure if this is an Urgent matter as the car now drives reasonably well and I rarely rev it very high....

 

[johntra]

i have not said that the car is running smoothly in higher gears..it lost its edge in third and higher gears..because it needs some more time to accelerate..it is not so edgy..the flat spots are only in 1st and 2nd ..so that is why i am now suspecting the pump..i check out other bravas and bravos in my city, neither one have the buzzing noise in pump..and that is all the time..not only in higher revs like at bravicssimo..and i have one more question..today when i was cleaning the car, ive opened the oil cap..and in the oil pipe there was a lot something like mud and grease..i am pretty sure that is mud..so ive cleaned the top of pipe..but there is still some of that thing down the pipe that i couldnt reach..i dont put so much oil because it is not spending it, so that is why i dont open the cap so much..what this could be, and could this be in motor too?..what should i do..

 

[jug]

what colour is this 'mud' exactly, black, brown, yellow, white? is it smooth like hair gel or lumpy like porridge? it sounds like the head gasket may have gone, which is pretty serious, and would explain why your car has lost performance, a blown head gasket will often prevent one or more cylinders from getting the compression they need. is your car loosing water from the cooling system? check the dip stick to see if it has 'mud' on it.

 

[johntra]

the mud is brown colour..i wrote that is mud cause it look like it...i can feel it between my fingers..and is lumpy i would say..and on it is some greasy stuff,white colour..and is coming from bottom..an also what i have notice that oil is leaking on first spark..on top of it and its leaving in that space where screws of the head of engine are..yes it is loosing water but not so much..it only happens when i drive the car hardly..it is not so big..i checked the oil today and there is no mud on dip stick..and there is normal amount of oil on stick.the head gasket i presume is not to expensive,but i think the job is big to do..whats the next step..to check the compression?

 

[johntra]

i dont think that this is problem of my car hesitating..you could be right that this is head gasket so i will clean the pipe and i will follow the situation..i think that you are thinking there is some oil and water mixture...the pipe was that colour since i bought the car..i rarely open the cap..but this is not on mine list of priority right now..when i get some money i will change all gaskests..and the leak of oil on top of first spark is very small amount..almost unnoticeable..and the lost of water is normal because i very often drive car hard...my priority is to find the answer of hesitation and i will try to check the pump first..but i will go to check the compression just to be safe...

 

[Tom444]

I have a brava 1.6 Mk2 and it used to skip. Especially in lower gears and lower revs, and used to "hiccup" when the car was idle. I took it into the garage a few times and got the same injector replaced 3 times!! They told me on the third time that I had gunk in the bottom of my tank, and as the brava has the whole pump inside the tank, the pump tried 2 suck up the gunk when the fuel was low, blocking the injector and ****ing up my engine. I was advised to keep my fuel above 1/4 full at all times, and since then the skipping has been fine.

Originally they reset my onboard, but this didnt help. The car judders at a constand speed in 1st and 2nd when going uphill etc, but when accelerating there is no problem at all.

 

[Tom444]

The white stuff in the oil is caused by water mixing with it in the engine. This is bad! This could also be why you are losing water.

 

[johntra]

mine problem is similar to yours..it judders at constant speed in 1st an 2nd..and i have problems when i am going uphill..when drive it uphil in 1st gear hard, and then i put it in second gear the car judders and hiccup too..i think the problem is because something is dirty..and i think the pump is..because i dont have any problems when the car is at idle..it runs normally..and with this second problem..i think too that the water is mixing with oil..but i am not loosing so much water..it is very small amount..and there is no white stuff on dip stick..it is just on the pipe..so the fixing problem will be to change all gaskets on engine?..and i will go to messaure compression, just to see and eliminate it if is good..

 

[jug]

yes i'd definately recommend a compression test, its the quickest and easiest way to assess the health of the engine. a loss of compression on one or more cylinders can be caused by damaged valves, worn piston rings or a blown head gasket, or the timing may also be out.

a healthy car shouldn't use any water at all, not a drop. if you are losing water it can only be a head gasket problem or a leak in the cooling system. either way it needs fixing before you have worse problems.

 

[johntra]

there is no leak in cooling system definately..so i presume the head gasket is blown..but what if my compression is to be ok,what should i do then..should i change the gasket anyway..but i dont think that mine hesitation could be the because of blown gasket..i am stickin to my theory of pump or injectors..