'94 G50: Another Q Bites the Dust

[sdkhalsa]

To my associates on the forum, I am sorry to announce that my Q has eaten it. In an attempt get the old machine running, the engine seized. I suspect the dreaded hydro-lock syndrome. The car is loaded with good parts including new tokikos, rebuilt front lower arms, 350 Z wheels with two new Yokohamas and two good Continentals, good transmission & rear end. The body and interior are excellent. Anyone wishing to buy the entire vehicle cheap, please let me know. The Q is in Phoenix. Thanks everybody for all of the excellent interaction over the last few years.

[Denver90Q]

Sorry to here of your misfortune.

How are the seats? Also, might be interested in the lower control arms. Do you know about how many miles are on them?

[Johnny Rocket]

Sorry to here of your misfortune.

How are the seats? Also, might be interested in the lower control arms. Do you know about how many miles are on them?

I dont think he wants to start parting the car out.....?

I would be interested in the car depending on how I can transport and the costs involved.

Did you fill the cyl up with fuel>?

[sdkhalsa]

I am not set-up to part out the car. The lower control arms have have new bushings and ball joints. The radial arms have new bushings. The upper arms are about 30,000 miles old. New Tokicos all around. Body and interior excellent, although driver's seat is not too exciting. You can see pictures on the infinity for sale site. New radiator.

There was a small leak on one of the injector o-rings and the engine back-fired a couple of times then locked. My guess is that there is a blown piston or rod. In either case, I cannot budge it using a long breaker bar on the main pulley(with plugs removed). The moral of the story is that the Q's have very low tolerance for flooding.

[3Q Jay]

sorry to hear it.you have the KL0/W combo that i also have...so if you *do* decide to part, let me know.

[maxnix]

So sorry to hear. Was something done recently involving the injectors? Didn't think they would leak spontaneouslyy unless the rings were left it so long they would decay.

Sounds like a JDM take-out rehabilitation and install would be the best bet.

[sdkhalsa]

Each time I replaced injectors, I had the older ones retested by a local injector shop. This shop had their own plastic end cap which in certain instances came off. It has been said in some posts on this site that injectors should seal even without this end cap. My thought is that while this may be generally true for certain vehicles, I don't believe that it is a reliable situation for the Q. The first time it occurred I had been running the car for a solid year during which the it performed flawlessly. Then, one day I was driving down the expressway and there was a massive o-ring blowout and flooding. I thought for sure that the engine was finished, but it turned out OK. From there, I put new O-rings on and pressure tested the rail. Some time later, another one of these blew and finished off the engine. It seems to me that the Q requires this lower cap to precisely position the bottom O-ring so that it does not deform.

[maxnix]

So you are not talking about the pintle cap?

Hopefully new to spec delrin O rings were used everytime.

Still think a JDM take out is your best bet.

That short block that Ryan had on eBay three or four years ago was in Phoenix. Wonder what happened to it?

[Q45tech]

Why I always recommend that anytime you change an injector you remove plenum, pull rail off, and reassemble on the bench where you can test orings to an over pressure using shop air..........................say 65 psi.

Changing an injector while the rail is on is just asking for future problems.

Do it yourselfers who have a short term failure learn the hard way that they were incompentent in their assembly skills.

[sdkhalsa]

Actually I am speaking of the pintle cap. I have seen several varieties of replacement caps for the original fingered design. I think that some have a similar stiffness to the original set-up while others don't do the job. A little later I will post a photo of the variety that I suspect is troublesome. There has been occasional comment about these plastic caps popping off and being found in the fuel rail or getting fried in the engine. Normally you would expect that the pressure of the injector would then hold the o-ring in place against the bottom of the chamber in the fuel rail. In my blow out situation previously described, the injector for the blown out cylinder tested fine and the recovered o-ring appeared to be good with no kicks or deformation. The plastic cap had come come off.

[Infinitiguy19]

The must be a way you can test while the injectors are in the car. But Sure it would be a hell of a lot easier to remove the rails and do it on a bench, But I think it would be OK to hook up a pressure gauge and do a pressure leak test while the rails are in the car.

[sdkhalsa]

In testing the fuel rail on previous installation, I had removed the fuel rail and pressurized it to 40 psi and let it sit over night to check that pressure held without leakage.

[Infinitiguy19]

That is good, I find it strange that the o-rings went like that, unless it was the E-10 that made them swell up.

You capped off the return line too when you did the test right?

[sdkhalsa]

Sorry to beat this topic over the head. I would like to first acknowledge the approach that Q45tech has mentioned. My point is that I believe a certain type of pintle cap can fail. In my first problem situation, the car had run without the slight sign of leakage for more than a year and then totally blew out all at once( pushed through about in four gallons of fuel in less than five miles on the expressway). The more common problem that most of us deal with is where the o-ring degrades and we have high fuel consumption, starting problems, or missing. The other common problem is where injector was not mounted accurately and you get leakage right away or almost immediately. What I am talking about is a different situation where the pintle cap comes off and the o-ring looses it's position.

[goody90q45]

I had hydrolock on two occasions in my 94Q early in ownership that fortunately didn't do any damage either time. I had fuel dripping out the cat and in the air filter on one of these. I share your pain though since my pintle caps have been missing also.

zerothread?id=175057

Sorry to hear about your Q. It looks like you tried to do all the right things to keep her running like new. Any idea what it would cost to have it transported to Sacramento?

[Infinitiguy19]

Who installed the pintle cap?

If it was you can you show us picture or provide a detailed explanation of how you installed the ring?

I have never heard of a pintle cap failure cause this sort of problem, \The pintle cap is there to maintain the spray pattern.

Did you use OEM O-rings?

[sdkhalsa]

I am a bit short of time at the moment so I will have to get back to you with more detailed information. The o-rings came from a local injector shop, and appeared undamaged when I later removed them. I suspect that you are incorrect about the only function of the pintle cap being to control spray pattern. I believe that that they also position the o-ring to sit properly against the fuel rail chamber. My thought is that due to the shape of the chamber in the Q this may be a more critical than in other vehicles. It seems to me that with the pintle cap missing, the o-ring may or may not hold position over an extended period of usage.

In terms of installation of injectors, I have been meticulous in doing this. First I use lots of vaseline. Next I push them straight down by hand till they click into position. For the recent installations which were done on a table, they went in very smoothly. Next I pressurized the rail as mentioned previously, letting them sit over night. After installation, I ran the car with a fuel pressure gauge t'd in.

[maxnix]

I didn't realize that the pintles held the lower O ring inplace.

Thanks for your explanation.

[sdkhalsa]

Perhaps Q45tech would comment on the function of the pintle cap. I am only commenting from my observation, not expertise. I have replaced two previous sets of injectors without incident and my problems seemed to have started with these light weight style of pintle caps.

[maxnix]

So are they OEM from Joe?

[Panther in a Q45a]

Please send pictures - I have any engine that needs a good car.

What are you asking $$?

[sdkhalsa]

I am asking $500. The pictures can be seen on the Infinity for Sale Forum: zer...arterTake a list of the parts that are in car, there are more.

[Denver90Q]

Interesting theory regarding pintle caps. What brand of injectors have you been using as replacements? Earlier 1990-1993 model seems to suffer even more from hydro-locking than the 1994 but probably for different reasons.

Your car must have been smoking like crazy if you used 4 gallons of fuel in 5 miles?

Sounds like you may have bent a rod. If engine if ok otherwise it might be a relatively easy rebuild?

I quess it would be best to test by applying pressured air to rail to at least 60-80 psi to ensure these don't come off inside the engine?

[sdkhalsa]

These were Bosch OEM injectors but with local injector shop pintel caps. The car was running great and then all of a sudden it started to buck and I headed for the next exit which was about 200 yards ahead. There was very little smoke, but at that time I was a little more focused on making an exit. Doing a search for pintel cap problems, there are lots of mention of 300zx's loosing them and the owners going to great lengths to dig them out of the intake. Most of the comments state that the injector will seal without them, but in the case of the Q I am skeptical.

[maxnix]

You do realize that German Bosch is not Japanese Bosch? Could parts have been mixed?

Never heard of pintles being dislodged in the Q45 injecotors before.

[texasoil]

pintle caps have nothing to do with O-ring sealing/position. I've never before heard of or experienced fuel leaks developing as you describe. O-rings seeping yes, gross failure no--sounds to me like a case of wrong injector in the rails. pre 94 ARE different side feed, though LOOK the same till you measure them. Later years are top feed and MUCH more reliable I hear.

I happen to know where a brand new, still sealed up factory 'Crate Motor' for 94-95 active is can be had very reasonable.

[3Q Jay]

I happen to know where a brand new, still sealed up factory 'Crate Motor' for 94-95 active is can be had very reasonable.

your garage? how reasonable is reasonable? i have BOTH a 94 and a 95 active as you know.