External differences w/ jspec engines?
09-03-02, 11:16 AM
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External differences w/ jspec engines?
Ok, I know the differences between the US S4 engines. My question is...are there differences w/ the Jspec S4 engines that will help me identify the year of the engine. I have a 88 Turbo II. I was told by the previous owner that he swapped in a Jspec engine in it (supposedly an 88), but he was unsuccessful in getting it to run.
Engine would crank, but wouldn't start. So, I'm in the process of figuring out if he wired up the car properly or not.
Any help or suggestions on checking the possible year of the engine (and whether it is US or Jspec) would be greatly appreciated.
Engine would crank, but wouldn't start. So, I'm in the process of figuring out if he wired up the car properly or not.
Any help or suggestions on checking the possible year of the engine (and whether it is US or Jspec) would be greatly appreciated.
09-03-02, 02:56 PM
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To tell if it's an '87-88 engine or an '89-91 engine, look for the knock sensor - if it's on the center iron housing, it's an '87-88. If it's on the rotor housing above the spark plugs, it's an '89-91.
The only real differences between Jspec and US-spec motors are in the intake manifold, throttle body, and the like, which may have been swapped out.
I'd just start on the typical no-start issues - vaccuum leaks, flooded engine, and timing not set right.
Dale
The only real differences between Jspec and US-spec motors are in the intake manifold, throttle body, and the like, which may have been swapped out.
I'd just start on the typical no-start issues - vaccuum leaks, flooded engine, and timing not set right.
Dale
09-03-02, 11:10 PM
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Originally posted by dcfc3s
The only real differences between Jspec and US-spec motors are in the intake manifold, throttle body, and the like, which may have been swapped out.
The only real differences between Jspec and US-spec motors are in the intake manifold, throttle body, and the like, which may have been swapped out.
hmm the TB is different? I am about to buy one to port and swap onto mine. whats the diff?
hmm I just thought of something. throttle cable pulling from other side of car?
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09-05-02, 02:10 AM
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09-05-02, 02:17 AM
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hahaha, good point 
I think the only difference was the number of vacuum nipples, I think the US has 4 and the jspec has 3. That's the ony difference I noticed at least.
I think the only difference was the number of vacuum nipples, I think the US has 4 and the jspec has 3. That's the ony difference I noticed at least.
09-05-02, 02:37 PM
#16
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Originally posted by Scott 89t2
hello Dale
what's the diff between US and J-spec TB's ??
hello Dale
what's the diff between US and J-spec TB's ??
The major difference on the throttle body is the Jspecs have a primary throttle stop adjustment screw that looks kind of like the TPS adjustment screw. They let you play with the primary throttle stop in Japan
. On the US throttle body, there's a small jam nut on the primary throttle stop.Besides that, they're pretty much identical.
Dale
09-05-02, 02:39 PM
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Originally posted by Icemark
No EGR valve on the Jspecs
No EGR valve on the Jspecs
The examples I gave above are to identify the *core* motor, not the stuff that's bolted onto it, which can easily be swapped over during an engine install.
Dale
09-05-02, 02:58 PM
#18
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Originally posted by dcfc3s
The '89-91 US motors don't have EGR either, so it's not a good indicator.
The '89-91 US motors don't have EGR either, so it's not a good indicator.
09-08-02, 12:59 PM
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Originally posted by SLOWT2
the j-spec engines are backwards, the fuel system runs backwards.
the j-spec engines are backwards, the fuel system runs backwards.
09-08-02, 07:29 PM
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the primary and second rails are switched
like when you do a nos fogger kit the line you have to tap for the fuel feed is diffrent cause the rails are switched
like when you do a nos fogger kit the line you have to tap for the fuel feed is diffrent cause the rails are switched
09-09-02, 12:51 PM
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I got a Jspec engine one time, that had a taller intake, and larger turbo and the manfold had no emmissions nor did it have a brake vacuum hole.
I was told by a Japanese guy who sold me the engine, that it had 220 hp stock!
I was told by a Japanese guy who sold me the engine, that it had 220 hp stock!
09-09-02, 01:08 PM
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Just to clear things up, the jspec 89-91 TB has 0 vaccum nipples on it. The only vacuum nipples close to the TB are on the UIM, there are 6 of them. The jspec TB, has the same throttle cable hook-up as the US spec. The primary idle screw was also mentioned, pretty cool thing to have, you can actually adjust the idle with the IC on =). Why does the us spec TB have all those nipples??!
The jspec stock IC has 0 vaccum nipples as well. The top says "Turbo Rotary" as opposed to Turbo II. The IC inlet/oulets are a little larger as well as the entire IC being a little bit bigger.
The jspec's BAC valve adjust screw is on the end of the BAC.
Yes, no EGR valve.
Also there is no upper radiator hose fill cap on the jspec's.
The jspec stock IC has 0 vaccum nipples as well. The top says "Turbo Rotary" as opposed to Turbo II. The IC inlet/oulets are a little larger as well as the entire IC being a little bit bigger.
The jspec's BAC valve adjust screw is on the end of the BAC.
Yes, no EGR valve.
Also there is no upper radiator hose fill cap on the jspec's.
09-09-02, 01:11 PM
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Originally posted by Barwick
you mean they pull fuel out of the air and put it in the gas tank?
you mean they pull fuel out of the air and put it in the gas tank?
No, I think he meant that the fuel starts at the primary rail and returns via the secondary rail. I didn't realize that this was backwards from the US spec versions though.
