mpcstuff

iTrader: (1)

So I finished the install of my USED TN kit with RC, 440CC injectors AAM fuel return system and UTEC. I did it myself - wasn't the cleanest install job so I trailer ed it to the local Z shop (works on a lot of Z's in my area). Main reason for trailering it was becuase I started the car for about 20 seconds and it ran like crap (smelled like fuel too) I shut it off and put it on a flat bed.

It was running bad so I assumed it was the UTEC tune that was for the previous car and running crappy because it was tuned wrong. After, I take it to the shop he starts it up and clearly realizes is running way too rich, wasnt there so im not sure how long it was run. His first thought which makes sense is that the only difference between my car and the car this kit was on before is that he had the TN reflash and then the UTEC was piggybacking off that. So my car was using stock ECU with the UTEC. The TN reflash is reflashed with the 370 injectors they use. So we figured we would reflash my ECU and that would fix our running issue. Make my car identical to the car the UTEC was tuned for (not the best way - but it will get it to run at least)

Finally after a week or so we get the ECU and it goes in yesterday.

I got a call this AM from the mechanic and he said it still ran too rich so he took the manifold off to check everything out and realized one of the injectors had been stuck open. He then put some RC 440cc injectors (same size as mine) he had in the shop in the car and the car ran fine with those in it EXCEPT for a ticking noise the car was making.

He said all the plugs looked good except number 5 and the compression test showed all cylinders good except the 5 was at 120. So at this point he is thinking that the Rod has bent do to the extra fuel dumping in that cylinder.

Does anyone have any experience with anything along these lines?


I do believe it could bend a rod if it had that much fuel causing it to hyrdo-lock with fuel but it seems crazy to me that a stuck open injector could blow my car up at idle.

Could it be a valve bent, or piston rings f'd, or is it likely the rod?

Now I am at the point of figuring out what to do. Have them take the engine out and repair just the one piston and rod (assuming that is the issue) or rebuild a built motor, buy a used one? I honestly have no idea what to do.

Labor alone to take the engine out so he can look at it would be $1800 then whatever it takes to fix what "may" be wrong.

Is there anyway to tell what could be wrong for sure before I spend the money to have this engine pulled out?

Any suggestions would help. I am pretty bummed - I have the money to fix it but this is not what I planned on spending before I even got to drive the car with the turbo on it. I assumed at one point I would be down this road but not before the car even saw boost.

Jay'Z

iTrader: (118)

Sorry bout ur probs.... Hope it gets fixed....

Dynosty

iTrader: (27)

Do a leak down test to identify where the problem is on the cylinder.

mpcstuff

iTrader: (1)

I guess I will tell him to do that. Excuse my ignorance.. Will it pretty much tell where the issue is?

Dynosty

iTrader: (27)

It should help determine if it is valves leaking, rings, etc.

mpcstuff

iTrader: (1)

Does it sound right that no matter what this engine would have to come out to do the fix whether its a valve, piston, ring or rod?

Its also strange to me that the car would run ok with just a slight noise with the rod bent. But I guess I have no idea.

And is $1800 fair on R&R

Nexx

iTrader: (41)

that slight noise will get worse and worse. the rod doesnt have to be bent it could be cracked or chipped and cause that ticking noise. if its chipped you could have metal flowing through your engine and jacking up all sorts of stuff like mine did. i was able to drive my car 15 miles home on the freeway when the ticking started so yeah, you can drive with your engine in bad shape.

i would recommend buying a good used block if you want a cheaper way out of it. sell your TN kit to help pay for everything if money is tight.

otherwise build the motor either way its not gonna be cheap. good luck, ive gone through this process twice now.

mpcstuff

iTrader: (1)

Money is there. Just kind of soured me on this whole turbo thing. I have other cars so its not hindering me from getting anywhere.

I do NOT plan to drive this car anywhere or even run it for that matter.

Z1 Performance

iTrader: (564)

take some heavier weight oil (trans fluid works well) and put a few drops into the cylinder that's low. If compression comes back up its in the block, if it remains low it's in the head

that being said I cannot fathom how 1 stuck open 440cc injector at idle causes a bent rod

mpcstuff

iTrader: (1)

Does anyone know in what condition a stuck injector could cause a valve to bend?

I understand the Piston and Rod Hyrdolock. Is it the same goes for the valve:?

athenG

iTrader: (2)

Weird, yes, are you alone? NO. This happened already were injectors stuck open and hydro-locked the motor. I wont mention the shop nor the owner but it pretty much the same case as yours were the car was only started for less than 5 mins and that was enough to **** up the motor.

Fleet Z

iTrader: (24)

As mentioned, have the mechanic do a leak down test. It's basically using air pressure to determine if the cylinder leakage is from the piston/rings, intake valve or exhaust valve, or head gasket. I agree that it is highly unlikely that the excess fuel from a stuck injector caused a bent rod the result of a hydraulic lock situation. If you had enough fuel in the cylinder, the engine would have locked during cranking to start. Seen that happen with coolant and a blown head gasket but never with fuel.

The ticking heard could just be the actual injector noise when opening. I wouldn't panic over a ticking noise just yet.

If you had a bent rod, you would be experiencing a rough running engine or severe vibration through the entire RPM band. My guess is that you have worn/stuck rings in one cylinder and although 120 psi compression is lower than normal, it isn't the end of the world or your engine. The stuck injector could have washed down the cylinder with fuel and caused a prematurely worn set of rings.

I like the "chipped" connecting rod comments...shows how little most of the people of this forum actually know. My wife chips her nails, but I have yet to see a chipped connecting rod in 25+ years of being around gas and diesel engines. Good luck...

Nexx

iTrader: (41)

got my chipped rod mine back from forged performance. i will take a picture for you just so you can see your first chipped rod in 25+ years.

Fleet Z

iTrader: (24)

Absolutely, please post some pictures of your "chipped" rod....I would love to comment. Honestly, your description of what happened to the engine in your car makes no sense. If a rod was cracked, then failed and broke, there would be far more sound than just a ticking coming from your engine. The engine would be knocking, skipping and pouring smoke out the exhaust. Maybe what you are describing as a "chipped" rod is actual physical damage to the rod, the result of an internal engine failure and damage from debris.

Nexx

iTrader: (41)

im just the messenger, i just just telling you what i was told and saw.

Fleet Z

iTrader: (24)

What does that mean "I'm just the messenger"....Where are the pictures of the "chipped" rod that sent metal filings through your entire engine?

Sharif@Forged

iTrader: (92)

If the injector sticks open with key on, for instance, or upon intial cranking, that cylinder is going to fill with fuel really quickly. 440cc is nearly 1/2 liter of fuel in one minute. The combustion chamber is about 40cc.

Best of luck.

Fleet Z

iTrader: (24)

Good point and something I hadn't thought about in my previous post.....The system is pressurized as soon as the ignition is turned on and an injector stuck in the open position would fill the combustion chamber. If there was enough fuel in the chamber, it could result in a hydraulically locked engine. Bending a rod is a possibility......

Sharif....I've read a lot of your posts and you definitely know your stuff. You are a pro. It's nice of you to contribute to the forum with expert guidance.

QuadCam

iTrader: (8)

your intial startup of the vehicle with the motor running like crap and the high odor of fuel...............sounds like 2 of the coils are plugged in backwards.

mixing up the coil plugs will do exactly what you described!!! it's an easy fix. just plug the right wires into the right cylinders!!!

I know this because I did it one day by accident. I was changing my plugs and perfroming a compression test. when I put the plugs back in, I mixed up the wiring between cylinders 4 & 6 (rear 2 cylinders on the drivers side.) the wires could go either way, and I was rushing. (oops.) anyways, when I started the car, it was idling really rough and wouldn't rev up at all. also, there was a pretty strong fuel smell. I knew there was nothing wrong with the motor as it was perfect before I changed the plugs. Initially, I thought I had a bad plug, but as soon as I was about to pull the plugs, I noticed that I had 4 & 6 connected to the wrong coils. switched them, and the car fired right up!

So, go check the coil wires! there should be a little tag on each wire with a number on them. depending on the age of your car, it is possible that the tags may have fallen off though.

Z1 Performance

iTrader: (564)

but the injector isn't open 100% at that point is it?

you can leave a car in the on position all day - the combustion chamber is not going to fill up with fuel