Strange Compression Test Results

[V]

1994 Integra, non-VTEC, 5 speed.

Car died on highway at some point, with no strange noises or slow power loss, almost like I suddenly lost spark. No start at home, naturally. No CEL / codes (bulb working properly). Checked spark, fuel, air – all good. Tested distributor, replaced ICM and a few other parts even though they tested perfectly. I am sure I put it back together correctly. No change.

Decided to do a compression test, because I was at a loss. I had no clue what I was doing. As such, I forgot to open throttle. Car was cold, since I can’t start it. Dry test.

No one on my usual forums can tell me what I am looking at, so I decided to go to the experts – been watching eric’s videos for ages. Here is my strange compression test.

Also, I know you are supposed to crank it 3-5 times. Subsequently, my camera died, but I got up to 165 (+/5) psi in each cylinder, at this weird, slow pace.

Norms for my car:
nominal: 199 psi
minimum: 135 psi
max var: 28 psi

Can anyone experienced with these tell me what this tells them? Thank you in advance.

Topic

[dave]

jumped timing.

[V]

jumped timing.

Haha, that was quick, and what I was afraid of.

So, I am pretty much looking at a new timing belt? A few questions:

1. If the valves were making out with the piston heads, I would hear it, right? Is there any way to verify that this isn’t happening, or it should be taken as a given, judging by the lack of noise?
2. I am not sure what these are called – but the “output gears” on the camshaft/crankshaft (what the TB rides on) – any chance these need to be changed? If so, are they easy to change out?

Thank you in advance.

[dave]

If the valves were making out with the piston heads, I would hear it, right?

You might have a ‘non-interference’ engine.

any chance these need to be changed?

I believe in cases of jumped timing, the proper repair would include replacing the major components that relate to your timing issue (the teeth of these gears may have worn down for example.) And of course, new timing chains and belts.

Here is a youtube on how to remove cam sprockets:

The belt driven crank pulley should be fine, but the belt itself should be replaced.

I have never seen your car or worked on your car, so you should not immediately buy into what a random guy off the internet says. You should verify the problem is in fact jumped timing. You could probably do this with a timing gun, or just turn the engine over by hand and try to observe your highest compression is at a point other than TDC.

Here is a case study of the cam sprockets advancing independently of the rest of the valve train:
http://www.automotivetestsolutions.com/pressuretransducersarticle.htm

Of course, we cannot make this conclusion for your specific problem. This is just one of many possibilities. (For example, it is possible for the crank pulley to move independently from the crankshaft. Also, the timing chain could have just jumped off a tooth) However, we can conclude since compression is affected on all cylinders, the problem is not cylinder specific (like a stuck for burnt valve) More investigation is required.

For the technician:
In this scenario, you could couple a graph of the ignition event over a graph of cranking amperage in order to diagnose timing issues quickly. This should be done for each cylinder.

[V]

Of course, you should verify the problem is in fact jumped timing. You could probably do this with a timing gun, or just turn the engine over by hand and try to observe your highest compression is at a point other than TDC.

Of course, we cannot make this conclusion for your specific problem. This is just one of many possibilities.

Any ideas on what else it could be? I literally have none other “worn starter/weak battery,” which I am not sure would make sense and would not cause the no no-start/no-run issue. However, I guess it could cause the starter pushing on the crankshaft weakly?

Oh, and obviously, I take this for what it is – “advice on the internet,” by no means do I expect any sort of guarantee. Still, it’s nice to have, since I don’t know any mechanics personally.

As far as setting the engine to TDC – I am reluctant to do that unless I have to, because I have to lift the engine a bit, and I don’t have an engine hoist / lift available. It’s doable, I would just like to cross out as much as possible before actually doing it.

Ty yet again.

[college man]

If you remove the distributor cap and crank the car.
does the rotor move? Your best bet is to remove the
timing cover and check the timing marks.

[V]

If you remove the distributor cap and crank the car.
does the rotor move?

Yes.

[college man]

check your timing marks.

[V]

ALL timing is good. Timing belt is in perfect condition. so are the sprockets. Checked distributor timing. Everything is where it should be.

Any other ideas?

[college man]

[Author]

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