Clunk!

[Z Factor]

Originally Posted by Don Nelson

So...is this a fuel injector problem...fuel rail...throttle-body?

The good news is that it is probably a leaking or stuck injector. The bad news is that it is probably a leaking or stuck injector.

In all seriousness, you will have to at a minimum replace the one faulty injector. That will be the least expensive route for you. However, you should know that the other injectors could start to leak (if they aren't already) or get stuck open. Since you are in Alaska and "not a mechanic" you will only want to do this job once since it entails taking off the plenum, fuel rails, etc.
So I would recommend that you replace all your injectors now rather than hope the others will last for a few more years. Keep in mind that you can just replace the faulty ones and may not have a problem with the others for a while. But for your peace of mind and possible cost savings if you have someone else do the job, replacing them all will probably be your best bet.

[tccrab]

Originally Posted by Z Factor

The good news is that it is probably a leaking or stuck injector. The bad news is that it is probably a leaking or stuck injector.

I predict a plenum pull in your very near future.

I'm sure one of us wouldn't mind flying up there for a weekend to help you with the job, providing of course a hunting or fishing trip could be added to the package...

[Ccmano]

I'd be very careful here. While the injector is no doubt the problem, we don't know if the hydrolic lock that has already happened caused any problems. You don't want to cause any more damage by installing new injectors and lighting her up only to find you had a bent rod that's now tearing up something else.

This engine should really be looked at by somebody knowlegeable (if you aren't) I would at least turn it over by hand with the plugs out and see if anything is hitting anything else. I would also measure TDC height on the one with the problem and compare it to a good cylinder.

While I haven't experienced it on these engines, I've seen Benz engines that have hydrolocked and caused a minor bend in the rod, only to cause more serious damage later on, and it doesn't take long!

Take it slow...

Hans

[Don Nelson]

Thanks for all the advice!

One last thing: By "replace all of the injectors", does that mean both primary and secondary injectors. Can I just replace the primary, and if so (and I know the answer here), can I use an aftermarket injector or should I stick with OEM?

[A26B]

Lots of good advice given. I might add that you should change the oil before running the engine. Fuel diluted oil can seriously damage rod & main bearing, cam journal bores, etc.

All of the injectors means primary & secondary. Leakers don't discriminate.

OEM: are very high priced.
RC: injectors are expensive, but worth it.
Accel: A relatively recent test of Accel injectors which are easily modified, have shown good promise and are the cheapest route to go. Search the ZR-1 section (archives) for Accel injectors to see the full story. Jeffvette will probably know the full story on them.

[flyin ryan]

Originally Posted by Don Nelson

Okay...the plot thickens...

I pulled one sparkplug to test the compression, but when I turned the engine over it locked again...so, I pulled all the spark-plugs and turned it over again. This time the second cylinder on the 2nd (passenger side) bank spewed fuel all over the place! After cleaning that mess up, I tried it again with a clean rag over the spark-plug hole and checked the rag (after it blew against the wall). It's pure fuel, but a lot of it. BTW: There does not appear to be any cross contamination between antifreeze and oil.

So...is this a fuel injector problem...fuel rail...throttle-body?

this is a best of a worst case scenario. drain the oil to see how much got past the rings. you might have got away very lucky. and that's O.K.

[Z Factor]

Originally Posted by Don Nelson

Thanks for all the advice!

One last thing: By "replace all of the injectors", does that mean both primary and secondary injectors. Can I just replace the primary, and if so (and I know the answer here), can I use an aftermarket injector or should I stick with OEM?

You can replace one or all, but if you only replace the faulty one/s, use the same brand (i.e. OEM with the same, or RC's with the same). I have heard of some people replacing all the primaries with one brand and having different secondaries, which seems to have worked out. However do not mix different injectors within the group as they could have different flow rates and spray patterns.

Though all of them can have a problem down the road, there are several people who have just replaced a few or one group (i.e. primaries). The only issue there is you can put everything back together and within days another starts to leak.