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-   -   wants to start (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/wants-start-1021884/)

shorty1408 01-01-13 12:59 PM

wants to start
 
i have a big problem. i have a 88 rx7 with a brand new j-spec turbo swap. s4 into s4. i have everything put together perfectly, the only problem is the injectors are not firing. please help if you have any idea of the problem. ive tried to start with 2 different ecus, checked fuel lines, pump, and spark. everything works.....

K-Tune 01-01-13 01:11 PM

Is the only problem that the injectors aren't pulsing?

Is there spark from the ignition?


If it were put together "perfectly" this thread wouldn't exist...would it?

misterstyx69 01-01-13 01:15 PM

More info.
what ecu's did you try to start up with?

shorty1408 01-01-13 01:27 PM

i tried the stock ecus to start up with. yes, they arent pulsing. spark, yes

jackhild59 01-01-13 01:53 PM

Did you swap the fuel line connections? If you hook up the USDM to the Jspec fuel lines, you will get no fuel. Essentially the jspec lines are backwards to the usdm.

Search, it's the most common problem in jspec swaps.

Another possibility: once I bought a jspec swap project. The primary and secondary injector wiring was accidentally reversed. The guy could not get the car to start under any circumstances, except when he towed it and the engine speed was over 3600-3800 rpm. Then it ran fine. When the rpms dropped below the secondary injector transition speed, the engine would die again. I figured the problem out and it was injector plugs were swapped. Turns out he had extended the JDM wiring harness (which is too short to use on the USDM car). When he deloomed and extended everything, he got it backwards.

So try checking if the secondary injectors are pulsing when you try to start.

Good Luck.

shorty1408 01-01-13 03:16 PM

Well, if the main fuel line with the fuel filter is suppost to go to the primary injectors first, then I got it right

shorty1408 01-01-13 03:53 PM

wonder if i have to use a usdm ecu, even though its a j-spec engine, its in a usdm car???????

satch 01-01-13 05:46 PM

Which injectors aren't pulsing? Only the primaries will pulse when starting and idling the car.

beefhole 01-01-13 07:15 PM

Since it was a jspec, it may have sat for a while. No such thing as "brand new". Perhaps the injectors are stuck. Did you check those individually to see if they are even clicking with 12V applied? Are you OK with the engine using the proper low OR high impedance injectors?

rumblz 01-01-13 10:57 PM

I used my usdm n333 ecu with my s4 jspec engine with the usdm harness. I think people say not to use the jspec ecu.

jackhild59 01-02-13 09:49 AM


Originally Posted by shorty1408 (Post 11331699)
Well, if the main fuel line with the fuel filter is suppost to go to the primary injectors first, then I got it right

check this:


Originally Posted by RotaryEvolution (Post 10847552)
if it's a Jspec block with everything on it from a Jspec engine then the lines should be reversed from the USDM setup. the line off the fuel filter goes to the rear hard line on a Jspec, front for USDM engines.


Originally Posted by iani1.1 (Post 10274468)
on the usdm
fuel flows to the lower rail first then to the top rail (primary to secondary)

on the jspec
fuel flows to the top rail then to the lower rail (secondary to primary)



try switch the fuel line first then prime it.



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