Power/fuel problem?

[Extasey]

Hey guys,
Yesterday I went to pick up 23(2)m of turf and on the way back I noticed that my engine would loose power for about 1/2 a second and then it would come back straight away, almost as a boost!
It will do this 3 of 4 times in a row as if it is "coughing".
The most common speeds it does it at is 55km/hr (4th gear), 70km/hr (4th gear) and 96km/hr (4th gear). It also does it at other speeds and in different gears but not nearly as often.
I think its a problem with the fuel being delivered to the engine, or maybe the pistons misfiring (spark plugs gone). Someone also suggested the dizzy cap might be fudged (never heard of this part of an engine, but apparently its pretty cheap).
The car is a 1990 Toyota Hilux (steel tray) with 320500km. Last service was at 320000km.
I'm taking it down to the mechanic tomorrow (to get rego) so I thought I would ask here first to try and get a general idea of the problem, and maybe even brase myself for the bill.

[ktmrider530]

Hmm, what the hell is a dizzy cap? lol
Any way, does it only do this when there is a load in your truck?

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Well, i figured out what it is, it's a distributor cap, pretty important component. I don't think that's what is wrong though.

[Extasey]

It started while there was a load on, and today i had another quite heavy load on. Seems to do it a little more often with a load but still does it whilst there isn't. Sometimes it does it sometimes it doesn't.
I have just been revving past those speeds in 3rd gear (55 and 70), which seems to help, but sometimes it will still do it in random spots.

[ktmrider530]

The fact that it dose it a certain RPMs is kinda weird. But because of that i don't think it has anything to do with your spark plugs or ignition system. It seems to be a fuel sending unit or fuel pump. If that's what it is, soon while you are driving your truck it is going to die. Now when this happens remember you don't have power breaks or steering anymore. If you are with a friend, have them get under the truck and beat the living hell out of your gas tank, while you try and start it. This should get you a few more blocks, then repeat the same process. My guess is that it will go out within the next two or three days. if that's what it is. Usually a little "cough" if something preventing fuel flow. It could also be something as simple as a fuel filter $8. A sending unit is about $150- $300. A fuel pump is about $40. Now, i'm not saying 100% that is whats going on. But for sure ask about it tomorrow at the shop.

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Also, ask about doing a compression test. That can tell them many things about the cylinders and heads.

[Extasey]

I don't have power steering, I have no idea about the breaks though (I doubt it?).
The '90 and '91 model didn't have power steering, so looks like i should be fine with that. If the breaks are run on power will the hand break work?

[ktmrider530]

I don't have power steering, I have no idea about the breaks though (I doubt it?).
The '90 and '91 model didn't have power steering, so looks like i should be fine with that. If the breaks are run on power will the hand break work?

Do you need to pump your breaks to get them to work? Eather way they will work, But it will take more effort. As for the hand break, it should always work, It's mechanical, so it's not with the other breaks.

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And what i mean by power, is that they are automatically pressurized. So if the power goes out, they will still work. You just need to pump them. If you turn your truck off, and roll down a hill it is pretty much the same thing as loosing power. It will actually be exactly the same.

[Extasey]

Yeah I was thinking that. No I don't have to pump the breaks.
I have no idea what will happen but shouldn't I be able to slow down with my gears (if need be?)?

[ktmrider530]

Yeah, no matter what your breaks will always work. You shouldn't have complete failure. It will just revert to standard breaks. So, you may need to pump them. You have a small truck so it should be no big deal.

[Extasey]

Cool.
Thanks for your help. I updated your +Rep.
Now I just hope it won't cost me that much to repair because I also have to purchase a CTP Greenslip soon ($800) *sigh*.

[ktmrider530]

Yeah, if it is in fact your sending unit, call your local junk yard. See if they have one. Much, much cheaper that way.
And no problem, I'm here to help.