Engine rpm waves and dies - why?

I have some problem. The Engine rpm waves and in the end the engine dies. It happens most times when it is warm.
Here you play some movies and hear it yourself. Any ideas what may be the cause?
Forgot to mention, this is stock 305 TBI

The videos are set to private. Change the setting so we can hear.

Try now

Have you got a vacuum leak?

BigBlackBeaSSt wrote:

Have you got a vacuum leak?

I will check it on Tuesday.

we had a truck that ran exactly like that. turned out to be the EGR valve. only happend when it warmed up.

Appreciated. I'll check everything on tuesday when I drive back to my mechanic. I don not have garage to work it on my own and its wet and cold outside.

My experience with that symptom is a failing fuel pump (happened twice). It is nearly impossible to check the fuel pressure. The prescribed way is to put a gauge between the filter output, and the fuel line to the engine. There is a fitting available for the TBI, but it is difficult to install. Pressure should be at least 9 psi to idle, but is supposed to be 15 psi.

It could be the ground at the right side of the thermostat housing. remove the bolt, clean the hole with WD40 (or similar) and a round wire brush (gun cleaning brush), the entire bolt, and the lugs. The ground is for the computer and the O2 sensor. If it is the ground, you will get a rich mixture.

Or the PCV valve.

The symptom will generally not throw a code, or if it does, it will be a lean mixture.

I'm thinking vacuum too.
Pete

My car made the same exact noise when it had a stalling issue. It was the fuel pump. I replaced it with Ac Delco p/n:25167089 . However, you should check your fuel filter as well, could be a clogged filter.

If you listen carefully, you can hear the noise:



Also, check to see if your fuel spray looks like this. Generally means a bad pump or sending unit:

I think that if it would be fuel pomp, fuel filer or injectors the car would do this "waving" right from the start. Last time it happened after 20min of driving. But I will check everything mentioned above.

MarcinV8 wrote:

I think that if it would be fuel pomp, fuel filer or injectors the car would do this "waving" right from the start. Last time it happened after 20min of driving. But I will check everything mentioned above.

Don't be so sure. When it happened to me it would drive fine for a few minutes then die again. Also, it could be the ignition control module. It caused the same issues as this on my car, as it sends a pulse to the computer to cut fuel when its bad.

Ignition module. under the cap. its shorting out, need more lube.

Cadet57 wrote:

MarcinV8 wrote:

I think that if it would be fuel pomp, fuel filer or injectors the car would do this "waving" right from the start. Last time it happened after 20min of driving. But I will check everything mentioned above.

Don't be so sure. When it happened to me it would drive fine for a few minutes then die again. Also, it could be the ignition control module. It caused the same issues as this on my car, as it sends a pulse to the computer to cut fuel when its bad.

Now I'm more worried. I will start with the simple thing - EGR and intake manifold gasket.

MarcinV8 wrote:

Cadet57 wrote:

MarcinV8 wrote:

I think that if it would be fuel pomp, fuel filer or injectors the car would do this "waving" right from the start. Last time it happened after 20min of driving. But I will check everything mentioned above.

Don't be so sure. When it happened to me it would drive fine for a few minutes then die again. Also, it could be the ignition control module. It caused the same issues as this on my car, as it sends a pulse to the computer to cut fuel when its bad.

Now I'm more worried. I will start with the simple thing - EGR and intake manifold gasket.

I wouldn't be too worried. The fuel pump, while an annoying job isn't super difficult, and the ignition module is right below the cap, so thats easy to change too.

Cadet57 wrote:

MarcinV8 wrote:

Cadet57 wrote:

MarcinV8 wrote:

I think that if it would be fuel pomp, fuel filer or injectors the car would do this "waving" right from the start. Last time it happened after 20min of driving. But I will check everything mentioned above.

Don't be so sure. When it happened to me it would drive fine for a few minutes then die again. Also, it could be the ignition control module. It caused the same issues as this on my car, as it sends a pulse to the computer to cut fuel when its bad.

Now I'm more worried. I will start with the simple thing - EGR and intake manifold gasket.

I wouldn't be too worried. The fuel pump, while an annoying job isn't super difficult, and the ignition module is right below the cap, so thats easy to change too.

I know. The fuel pomp is new (previous owned changed it right before I bought the car). But I didn't check the ignition module. The car spent almost 3 months in repair shop - I want to drive finally

I had a new pump fail in one month, and the replacement failed in a year and a half. The original problem was a torn rubber hose between the fuel pump and the metal output line in the sending unit. I replaced the hose and the pump died about a month later, then I replaced the pump with a Bosch, and it died a month after that. I made the mistake of putting a replacement Bosch pump in, and that is the one that lasted a year and a half. I now have AC Delco pumps in both of my wagons. The symptoms were the same in the first three cases...idle swooping up and down. The last pump failure...stalled a couple of times, then just would not start.

If you are going to replace the ignition module on the distributor, remember to put heat sink compound (white paste from the electronics store, not the automotive parts store) on the bottom of the module, or it will quickly fry.

Do not replace the intake manifold gasket or the EGR valve, you will be wasting your time and money.

You can check the EGR valve without pulling it. Disconnect the hose, and use a vacuum pump to suck down the line. It will open the valve and if it changes (dies) then the valve is good. You can also squirt some water with a little dishwashing liquid (about 3 drops per quart) around the gasket of the intake manifold, and if it sucks it in, and the engine idles correctly for a few seconds, then it has a leak...if it does not, you do not have a leak. You can also squirt some on the vacuum hoses to check them as well (same results = same diagnosis). The PCV valve is an easy and cheap fix too. Do the easy cheap stuff first.

Listen to the people here. They have been working with these car for a long time and know what they are talking about. I had to figure all this out by myself, because I did not know about the forum until I had the White Elephant about a year. By that time I had gone through most of the problems that occur with these cars, plus some self inflicted ones.

Look at what Fred boldfaced above. I think it's either the Fuel pump or that stupid little rubber hose. I have a sticky on here on how to drop the tank. I would drop it and check that hose first. I had a bad pump, swapped in another one and didn't notice the hose was split.

I spent the next couple of weeks, changing fuel filters, rebuilding the throttle body, changing that ignition module, cap, wires. rotor, only to find out the problem was still back in the tank.
On the upside, I KNOW the fuel delivery system is good now, but I spent over a hundred dollars for nothing. I'm sure parts in Poland are a bit higher.

Even with the split hose, the spray pattern at the TBI still 'looked' ok, but it wasn't enough.

I had two TBI cars have the exact same sound and both times it was in the tank.
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Fred Kiehl wrote:

Listen to the people here. They have been working with these car for a long time and know what they are talking about.

That's why I ask. I'll check everything listed here, and I will start from checking the fuel pump.

I had a similar problem with mine. How many miles on yours?

Turns out it was the distributor on mine. The shaft was worn out, so the idle air control kept chasing the timing and over/under adjusting eventually causing the engine to stall...

He has something about 93 000 miles

MarcinV8 wrote:

He has something about 93 000 miles

Shouldn't be what I had an issue with then - I have about double that on mine.

MarcinV8 wrote:

He has something about 93 000 miles

Little correction, my wagon has about 146 650 miles
They checked everything you guys mentioned. The fuel pump is working properly, fuel filter is new, EGR work perfect. Everything is fine.
It turned out that the cause of this waving is timing chain.They set the ignition and the waving stopped. Now I'm waiting for new timing chain and cams.

Thanks guys.

The timing chain is seldom the issue, but when it is, you have to replace it. You get the gears with the chain, not the cam.

I figured it. I just went threw the same thing. But I changed the ignition module. then set it.

one of these days it really will be the fuel pump,..

You are right on carlos,. i think marcins' mechanic is out for a little money,. i doubt the chain is that loose,.

Nick

It's funny how there were about 4 different possiblities for the same symptoms.....after having to do 3 fuel pumps in less than a year, I'm biased, lol.

Just thinking about what MarcinV8 wrote. I if they set the timing, and it stopped, why does he need a timing chain? Sounds like a ripoff if you ask me.

Fred Kiehl wrote:

gears with the chain, not the cam.

I meant gears, damn translator.

Fred Kiehl wrote:

Just thinking about what MarcinV8 wrote. I if they set the timing, and it stopped, why does he need a timing chain?

Because it is loose. The car has almost 150k miles and probably no one ever changed it. When I drove it back home I figured out that probably no one invested any money in this car, there were so many tiny broken things. It was just some fun to drive (sometimes) car but when it needed investment - hmm, it cost money. Previous owners should be beaten with a baseball bat.

Fred Kiehl wrote:

Sounds like a ripoff if you ask me

If I had proper conditions like quite a big garage, lots of tools and some spare caprice for parts I believe I would do it myself - with your help of course. I'd ask a lot questions

I am not in front of the car to see the actual parts, so I can not judge the condition. Timing chains have worn out before, so your mechanic may be correct. The timing chain is not absolutely tight, but it does have its limits as far as being loose.

If you need a Factory Service Manual for the car, they are often on ebay. Pricing can be as low as $15 + shipping. The 91, 92, or 93 manuals are all the same, except, I believe the 91 does not have the information about the 5.7 liter engine.

all years avail currently

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Sprocket wrote:

all years avail currently

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Thanks! I have to buy this. I only have Haynes repair manual
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Nope, It's probably not the timing chain. But I will replace it anyway just to be sure...
My friend visited me and he found three errors instantly; EGR, ignition and some other. He diagnosed it without a computer using only a piece of some wire found on the street that he put in the diagnostic socket, and the "check engine" started to blink...
Now he's got my wagon . I hope he will do it fast.

What a day! I'll write you guys what happened when I'll be sure what I heard today about my wagon. This is fntastic news

So it turned out that the engine in my wagon is a crate engine Goodwrench 5.7 (part number 10066036), not the stock 305. The injectors, throttle body, intake and the computer is from 305. Maybe this is the reason why the car doesn't work as it should. So now I look for pair of perfect working 5.7 injectors
I'm quite happy because what can be better that big displacement? Only bigger displacement

I hope that after reprogramming the computer it will work better, but I will have to buy injectors for 5,7.

Crate motor being suffocated by a TBI?

Time to make it FUN.

Stingroo wrote:

Crate motor being suffocated by a TBI?

Time to make it FUN.

Unfortunately it will be TBI. I got the injectors.

You only need the PROM in the computer to have the 5.7 programming. You do not have to program the entire computer.

marcin,. i,m pretty sure the throttle body and injectors are the same for the 305/350,.

I used to go here for my info about 10 yrs ago,.

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Nick

phantom 309 wrote:

marcin,. i,m pretty sure the throttle body and injectors are the same for the 305/350,.

I used to go here for my info about 10 yrs ago,.

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Nick

Unfortunately they are not the same. The 5.7 injectors have bigger flow. Thanks for the link, I can see few very interesting informations

So.. it's been a long time

It turned out that I have to rebuild the engine, completly. I have all the parts, finally!. Now I have to repair bearing shells (don't know if this is the right name), and few other parts like new valves, than program the computer.
There is a small chance to get this running by the end of this month.
Updates soon.

That really sucks. It is hard to believe that the crate motor didn't last longer than that. they are basically the same as the OEM 5.7 which usually last about 350K miles or more.

You only have to get the prom for the computer. I may have one. they are small and easy to replace.

It is inevitable if you drive without engine oil most of the time.

Who drives without engine oil except for teenagers who only fill the gas and expect it to go forever.

Fred Kiehl wrote:

Who drives without engine oil except for teenagers who only fill the gas and expect it to go forever.

Damn f%&g idiot previous owner. What can I say, I have to rebuild the engine and he will be fine for another 20 years or as long as UE will let me keep it.

Good news! My Wagon is working. He now has 5.0 TBI engine (the same as the original) with around 54 000 miles on it. The old engine is completly damaged.
Now the car is in the garage for the winter, he will hit the road in 2013
I will have to check the transmission, because its generating some weird sounds but it drives fine. It costed quite a lot of money so now I can't sell the car for like another 5-8 years

I am glad to hear that you have finally fixed your car.

I have so much money in both of my cars, I can never sell them. I will probably be buried in one of them.

Few pictures ... I wasted a lot of time and money trying to repair old engine. I should buy an engine long ago but who would know.. after taking the engine out, disassembling it it appeard that repair cost is higher than buying new one. My friend sold me an engine from his Firebird because he bought some time ago some 5,3l and was lacking motivation to install it in his Firebird. Well, now he has a lot of motivation

Engine out...
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Looks like Caprice offroad
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New Heart
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This is the only one Caprice Station Wagon (european version) in such good condition in Poland.

Glad you got another engine and dont worry,after a few years of driving the wagon you will find
yourself very attached to it.Have had my first wagon going on 9 years and I just cant imagine
ever selling it!

Glad to hear you are back in business. Too bad is cost so much effort and money to get this far, but you will love it when it is running correctly.