My vert recently started to hesitate and spit and sputter anything below 4000rpms. It sounds kind of like running on one rotor but then it opens up at 4000rpm. If you drive it for over 2 hours straight without shutting it down it will run semi-ok but still not like its supposed to. I have verified its not a vac leak. This one really has me stumped because somedays it has tons of power other days it has none at all until the 4000rpm.

I really need some help on this because i want to drive the car until it comes off the road this winter for the turbo swap and widebody.

 

I would say primary injector cloggage and check wiring to primarys.

john ny

 

I thought the cloggage issue too. So far ive run like 5 bottles of injector cleaner(almost all the good brands) through the car and still no improvement. I even changed the fuel filter and cleaned the fuel pump sock.

Anyone think it could be one of the aux ports i wired came undone and the other is open? just a thought

 

1. Check for trouble codes
2. Check for closed loop operation of the emission system
3. If you wired the aux ports open, it is likely to run rough and lean until the secondary injectors come on at 3800 rpm. Try putting the aux ports back into normal ops?
4. EGR stops somewhere around 3500-4000. Check proper operation of the EGR valve?
5. Port air/split air also stop in that rpm range; check operation of those per FSM
6. Adjust TPS to exactly 1k ohm at idle throtle
7. Check TPS for any reistance dropouts through its full range of operation
8. Get a stethescope and check for clicking sounds of primary injectors in the rpms within the range you are having difficulty
9. Check timing and advance per FSM
10. Check for proper operation of double throttle diaphram
11. If you took the aux ports out of operation, did you maybe leave a hose off of the boost sensor (in between the actuators), or have a vac leak at the aux port solenoid valve?

 

Will do all the above. If it turns out to be a problem not worth fixing on the n/a motor i will just pull the insurance and all now and start tearing down for the turbo swap.

 

take out the top two spark plugs(trailing) and crank the engine to listen for your compression strokes. make sure you have even strokes no gaps between the sounds(3 strokes on each rotar housing) if one is missing or noticably weaker then the other your problem is low compression due to lost or worn down apex seal. you can also check your cat's my friends cats where super clogged and his car wouldnt rev well before 4000rpm. we hollowed them out and after that it ran just fine. it could be a mix of issues check your injectors physically to make sure there working ok. running injector cleaner wont help if ones not working for a different reason. if none of this helps i say tough it out and wait untill winter when you swap it anyways :P not to far off now

 

1. If you have a stethescope, you can check the primary and secondary injectors for normal operating sounds (clicking).
2. Regulated fuel pressure: is it ok under 4000 rpm?
3. O2 voltage values in the ranges with and without the problem? Under 0.45v is lean. That is easy to check and might direct your troublshooting, i.e. inop/clogged primary injectors, etc. If you wired the 5th and 6th poorts open, the mixture may be too lean until you get to the rpms where the secondary injectors come in. the O2 sensor voltage would tell you.

 

lol Had that problem... Was a crack apex seal for me... It would misfire/hesitate until 4000rpm, what caused this was leaning out to much.

But i'm sure yours is not that case.

 

Well i checked to be sure both aux ports were still wired all the way open and one wasnt. But then after checking to see if the problem had gone away it didnt so when my friend shut the car off i could hear a loud clicking coming from the primary injector area. So i think i just to get it home from his house im going to swap the primary and secondary injectors and just not take it above 3800 rpms. Then just not drive it until i can pick up some used n/a injectors(let me know if you have some).


Just another side note. The air hose coming off the back of the air pump ripped on me will i need to cap off the part it supplied?

 

You can always send your injectors out to get serviced. Buying used injectors you still have no guarantee. I had some injectors serviced by kgparts.com. They have a really good turn around time.

 

I figured i would grab some used ones recently serviced. ITs not like they will get more than a few hundred miles anyways since November 1st the car is getting parked and torn apart for the turbo swap, widebody, and other goodies.

 

i had the same problem and i wound up being a loose connection in injector harness. some idiot butt connected the wire and poorly and i pulled out and would sometimes fire when wiggled the right way lol. just a thought

 

i will try that because for a few days after the engine bay wash down it ran fine