I am trying to finish up on my turbo swap.. having some issues. the car will run. i have to hold my foot on the gas though at about 1500 rpm, i let off, it bogs and dies under 1000 rpm, i step on the gas a little, it climbs, if i go more than 1/4 throttle, it cuts out and backfires. im not sure i can set the tps as i dont want to run too long in fear of some damage. it is at 1k idle and 4.1k WOT as of now though. ive checked my vacuum lines, caps, etc. replaced what i needed and STILL does it. a rundown of the car..

88 gxl (na) with s5 turbo block, manifolds and tb. s4 tps is mounted on s5 tb. where the original narrow range was. all cold start/emmisions removed.... fmic, bov, cut my old injector plugs off, installed s5 ones as i already had s5 turbo injectors. high imp, i have no resistors for em. but i do have an n332 ecu (low imp injectors) if that makes i difference, im not sure. ive read it does not.

It has ran and idled on its own before. it had the same problem with the cutting out under throttle. i have s4 turbo afm, boost sensor, etc.

any ideas guys?

 

you need to run an S5 T2 ecu or an s5 vert Ecu . also double check your grounds. Are you using the turbo map sensor?

 

i do not need the s5 ecu as my electrical is all s4. that would be a mess.. and yes, i stated that above. s4 turbo boost sensor (map) i have checked my grounds also. although i may redo them at some point just to be 100% sure


didnt state above i am running this on s4 electrical components

 

also i am running a walbro 255

 

what engine harness did you use?

 

s4 na harness

 

do you still have the resistor box?

 

Sounds like a garbage AFM. You are using the TII AFM, right? Also, was the engine pulled from a running car? Was the CAS moved any?

 

new afm, reman unit. and yes its turbo afm. ive checked and checked about the resistor pack.. i dont belive i have one.. can someone snap a pic of the injector resistor pack to make sure i dont? i know if i do ill have to unplug and jump the plug. engine is a rebuilted s5 turbo by ernst at rx7world. cas was removed but was installed properly. more than once have i checked that.. ill unplug it and see what the car does. i will also clean the plug to the afm, and the tps. maybe bad connections...

 

Resistor Box

https://www.rx7club.com/showthread.p...enoid+resistor

 

^yup

since it is a s4 to s5 swap and your injectors are still s5 meaning, you s4 electronics will only work with low imp s4 injectors. you can take out the resistor box out and splice those wires from the plug altogether. now i dont remember what goes where but im sure someone on here knows.

 

thanks alot. but.......... ive confirmed i do not/never had one. has factory plugs where the bolt holes go for it. my car is past 88 1/2 i guess =p

im going to check the afm. put my old n/a s4 one on, just to check. i believe it will be a bit richer but if it is then it should actually run though. ill do that tomorrow

 

ah got cha.

you can always just adjust the spring tension on the na one. i think thats the only difference between the t2 and na afm.

 

thats what i have read.. ill see what i can do. thanks for your input. i appreciate it so far

 

tried the afm.. same result. it responded a little differently but nothing to get excited about. after work i will mess with it some more in this 100+ degree weather. i will see where my a/f is also

 

another question.. you can rewire the injector plug wires either way, correct?

 

Yeah. Matters not which wire goes to which pin in the injector plug. YOu do need to confirm the primary injector elect plugs are on the primary and not the secondary injectors.

Do a compression check using your ears and finger to see if you've lost a apex seal.

Might just disconnect the TPS connector to see if there's a difference. Small chance that's a problem. Not much of a chance of that being it.

 

Ill check the injector clips. I can hear heaps of compression, but will check. Thing is, I've tried 2 tps sensors. Ill see what I can figure.

 

Whats the difference in the primary/secondary injector plugs?

 

Nothing.

 

IF you put the primary injector plugs on the secondary injector and secondary plugs on the primarys, the car won't hardly idle/run. Seondary injectors only work when there is a load on the engine and the rpm is over 3800 rpm. Primary injectors work all the time.

I should stop here, but......................the primary plugs wire are attached to the ECU and only get the primary signal from the ECU.............nah, going to stop right now. The physical shape of the primary and secondary injector elec plug are exactly the same. But primary go to primary injectors..........secondary go to secondary injectors. Shoulda stop when I said stop.

 

Yes this makes sense. What will be a visible difference in the plugs? I havent checked them out yet. so would this be very lean..?

 

I misunderstood I think. You are saying as if I had the primary wires from the ecu going to the secondary injectors themselves.. I was thinking you meant the actual plugs function different

 

The primary injectors are the ones installed in the intermediate housing. The secondary injectors are installed in the intake manifolds secondary runners. Not a whole lot of air is going down the secondary runners at low throttle so if the secondary injectors were firing due to the injector plugs being installed on the wrong injectors, then the car would run crummy.


The front primary injector has two wires. One should be colored light green. The rear primary injector should have one of its wires colored light green/black.

Only the primary injectors work below thirty eight hundred rpm.

I don't know if this is your problem or not. IF the engine has idle good prior to lately..........then this is not your problem if you have not been messing with the location of the fuel injector plugs.

A internally hung up TPS can cause somewhat similar problems, so if you just removed the TPS plug from the TPS and gave it a try, and things did not get any better, your problem isn't TPS related and you can try something else.

 

I recall something about the variable resistor needing to be changed out too when doing a TII swap. I think it only controls idle enrichment, but I may be wrong.... Did you change that? Now, you said that you've checked that the CAS was installed properly, so I'm going to do a dummy check. How did you install it? And you can't just unplug most things on the FC to see if it'll run better. Especially the AFM or CAS.