Hi everyone,

I need some help with an issue I'm having. I bought an 88 S4 rx7 a while back and the coolant seals were gone, so I sourced a japanese S5 engine and performed the swap. I used the S5 block and swapped everything over from the S4 wiring and accessory wise. Now here is the problem:

When I crank it over, the car sounds like its about to start but then doesn't, over and over again until it eventually floods. The car came with a switch for the fuel pump already, so when I turn the switch off to deflood the car, the motor will start and run until it runs out of gas.

Based on this, I know its a fuel issue, but the thing is I can't find anything that is obviously wrong with the fuel system. I don't see anyleaks, and the vacuum lines look okay to the regulator etc. I am not very experienced with rotary motors though, so your help would be greatly appreciated. Any ideas on where to look?

THanks!

 

Having done this recently myself and experiencing the same symptoms, i would highly recommend you check every hose or fitting and gasket from the air flow meter to the engine. I was surprised how small a vacuum leak could have such a big effect on starting. Mine would crank and fire right away and then die. Over and over. ended up being what i would have thought wasa tiny unimportant leak, but once fixed she idled perfectly.

 

Re-zero the timing. Put some oil in the plug holes. Once it starts, make sure you have the timing set correctly. 20 Trailing (top plug), 5 Leading (Lower). If it dies as soon as it starts, try going under the hood and having a friend hold the flapper for the AFM open a little bit. If it keeps dying, your looking at a bad fuel pump.

Usually im not picky about it but not many people even bother with the search function on this forum. Theirs about 7-8 years of information fixing issues with these cars on this forum. I'd suggest trying it.

 

Check the fuel lines. JDM hooks up different than the USDM. Make sure the fuel supply line goes to the fuel rails then the return is hooked to the Fuel pressure regulator. If you hook JDM up the way your USDM was hooked up, the fuel supply line will be going to the pressure regulator first instead of the fuel rail-and it won't work.

 

Make sure the AFM is working as well. When I did my T2 swap that's what finally ended up keeping me from firing up the car. The FSM shows how to test it. When I replaced mine it fired right up.

 

OK, if you are sure of the vacuum leak thing, then I recommend-

Turn on the ignition
Walk around the the afm and slowly open the meter vane
listen for a "click" followed by the sound of fuel running through the rails.

If this works, then your AFM is most likely OK

If you heard the click, I would find the yellow open connector behind the filter box near the passenger side front shock tower and with the ignition on again, jump this connector with a wire. Leavde the wire there and be sure no exposed metal from your wire can ground on anything. Then go crank the car.... Let us know what happens....

Next, with the yellow (its a fuel pump AFM AFM switch override which kills the pump if no air is going through the engine) connector still jumpered I would use some type of tool to retain the metering vane about half way open. Try to start again. If it stays started here...get back to us....

Good luck !

JJ