WindyCityZnut

It doesn't matter at all. It has been running in this configuration fora long time. A couple of the wires got damaged and I want to source a replacement.

I found out that the injector harness on this car is actually from an SDS system. Mystery solved. Now to see if I can order a new one. Thanks!

Here is a picture if that helps.

Here is a picture of the connector if that helps.

Well I finally got a chance to get back into the garage this morning after delays for a track weekend and some minor surgery earlier in the week. On your advise, I starting checking on the wiring. I cleaned up a couple of grounds. Found and replaced 1 bad connector. When I was tracing the fuel injector wiring I discovered that the harness had fallen onto the rear of the exhaust manifold. Several of the wires had their coating melted. One was actually stuck to the manifold and possibly grounded to it. Looks like I need to replace the harnesses. Unfortunately, there is no part number on it. One of the connectors at the harness end had "P.E.D. 25" embossed on it. Any body recognize that?

I know they are staying open because they completely filled up the cylinders with fuel until it was hydro-locked. Fuel even got into the crankcase and the exhaust through a couple of open valves. We pulled the plugs and cracked it. It sprayed fuel across the room like a gieser! I need to put in some fresh oil and circulate it through the engine to clean it out. I am not sure how to clean out the exhaust. I aqm afraid to try and start it now.

Unfortunately, I did not get one with the car. Is there somewhere I could ship it to get tested?

For starters, I am just starting to learn MS, as I have only owned this car for about 5 months. Here is the set-up of the car as I know it: Stock L28 turbo short block P90 head Delta cam Schnieder springs, light port work. BHJ damper 550 RC injectors PT61 T4 turbo( GT35R compressor wheel, P trim .58 hot side) 35mm WG Running Megsquirt 'n Spark extra, MS1 I believe I had a very reputable shop dyno tune the car a couple of months ago. It seemed to run strong when I got it back. Then I got side-tracked when the head gasket blew. Got that fixed and was working on getting the car running again. As soon as I put power into the system, the injectors open, without even cranking the engine. I took it back to the shop for some help in trouble shooting. We verified that the tune is still in the MS that was set during the dyno tuning, however it fires the injectors immediately. The mechanic thinks that there is something inside the ECU that has fried. Is there a way to check if the CU has gone bad? Has anybody else run into this issue? I have search for several hours now and could not find a similar problem. Are there any MS guru's in the Chicago area that would be willing to give me a hand trouble shooting? Thanks, Marty

Relax. The last thing I want to do is make this more complicated! I already stated that I was going with the tried and true cam tower shim method. I was just responding to 2eighTZ4me's comment that he had never heard of "headsaver shims". I was just telling what I learned from the shop and the relative merits of using this as an alternative for discussion purposes. Personally, I like to error on the side of too much info, as opposed to not enough. I am ordering the cam tower shims today. Thanks for the help! Marty

Actually, he does a lot of Hondas,and Toyotas along with a bunch of Chevy's. They just don't see these engines anymore, since they all rusted away years ago around Chicago. As he explained the head saver shim to me, it is made out of steel, about .020" and gets sealed in place just like a gasket. It builds up the mating surface to make up for what was shaved off. It almost sounds like a metal head gasket. You then put your head gasket on top of that. The Pro's that I see are: 1) It is easier to install than the cam tower shims; 2) it won't change the CR; and 3) when used with the stock head gasket, it still gives you the safety of having the gasket blow before internal engine parts break, if you went with a metal head gasket. The Con's that I see are: 1) it might just create another area for potential leaks; 2) it is an unproven fix in the Z world. He is checking to see if he can still get one. If he can't, well, it makes that decision a whole lot easier. But, like you said, it is probably better to go with the tried and true method. Thanks for the input. Marty

I talked to my machine shop again this morning about putting in cam tower shims. He said he could not get them from his suppliers any longer. He recommends going with a head saver shim. This sounds like a simpler solution. He thought that there was no technical advantage for cam tower shims over head saver shims. He said they use them all the time in his industry. He may be able to get the head saver shim. Do you guys have an opinion on which is a better method for L6 engines? Thanks, Marty

The shop checked the top of the head and it is flat and the cam spins freely. It was milled top and bottom the first time. I will have them measure the head. A search revealed that a stock head thickness is 107.9mm, correct? The Tomei gasket has a 91mm bore, where the block has a 89mm bore. Someone here has run that in a track car successfully. The other concern is that the head gasket may hold up, but it may blow other engine components, like rings, pistons, etc. with detonation. There was a lot of detonation showing on the old gasket. I can't tell if that was happening before or after I had it dyno tuned. I have to assume that it was before since it was running really crappy, barely running at all actually. It would be better to be safe with a stock gasket, like you suggest. By the way, this is a P90 head and the boost is set at 15 PSI. Will shimming the cam towers require other changes in the valve train? Thanks, Marty

The head gasket on my race car blew recently (280ZX, T-4 Turbo motor). I took the head to a local engine builder to get checked out. Got the news today. The head is warped .013, needs new valve guides and seals. The previous owner told me that he had this head shaved .008-.010. So, if I get it shaved another .013, I thinking I will need to get a thicker head gasket, right? I am concerned about too much chain slack or even throwing the timing off. The engine builder recommended getting a Cometic .060 thick gasket. I did a ton of searching on the internet and could not find a Cometic gasket for this engine. I did find some discussion of Cometic gaskets being made out of copper and that you would need to o ring the block. I did find a Tomei metal head gasket that comes in 1.2mm, 1.5mm, or 2mm thickness. Anybody ever heard of this one or used one? So, what would you guys recommend? Thanks, Marty

I went back after a short break and looked at it again. Then I turned the engine slightly in the opposite direction. That took the slack out and allowed the tool to slide in. Sometimes it pays to walk away and get a new pespective.

Last time at the track, the race car blew the head gasket. It's a 240Z with a 280ZX turbo motor. Today I finally had a chance to start taking it apart to replace the gasket. Went to put the chain tensioner tool in to prevent the tensioner from popping out and it would not go in at all. When I looked closer, the spark plug side has got good tension, which you would expect with the tensioner on that side. The chain on the manifold side is very loose. The last time I pulled a head (different car)the tensioner tool slid in easily. Now I can't even force it in between the chain. Anyone have ideas on what would have caused this? Any suggestion on what to do next? I really don't want to pull the front cover if I don't have to. Thanks, Marty