fuel cut at redline and under semi hard load-searched

[s20700134]

my car(1989 s13) cuts fuel at 6250 rpm and doesnt kick in until i let the revvs go down to 3000, and that is if it didnt cut alreadyfrom being underload. like, if im going up a light grade hill, it will cut fuel before redline(where ever it feels like its working kind of hard i guess?)and i have to coast down to 3k or push in the clutch in till the revvs drop down to 3000 and then im going again. this happens in all gears(not really first, not enough load?) esspecially on the freeway just at about 3500-3600.

all and any help on this would be greatly appreciated.
Modified by s20700134 at 5:37 AM 2/11/2008

[s20700134]

the car is bone stock with the ka24E btw.

[Vegascorbin]

This is the exact same symptoms we had with our race car. Unfortunitly we blew a 3x5 inch hole in the side of the block before we figured it out. Currently working on re-building another block.

Things we tried:MAF (replaced from another car)All 4 injectors (Used from E-bay)Full trans Swap (due to shifting problem)TPS (New From Auto Zone)Checked with Starting Fluid for Vacume Leaks None FoundFuel Pressure Regulator (Swap from another car)Fuel Pump and Gas Tank were Changed when Race Fuel cell was installedFuel FilterAir FilterSpark Plugs And Wires

About the only thing we did not try was a new O2 sensor. Auto Zone was out of stock and we blew the engine before we got one. The other thing we were looking at was re-doing all of our grounds even though they checked good. It is possible it was some other electrical gremln but it is hard to check thing out when the car has been stripped down for Dirt Track Racing and we ar not the ones who converted it.

I doubt the blown engine was related. It started Knocking like crazy the day before it blew.

I know this is not very encurageing but it may help.

[s20700134]

thanks alot for the help. did any of the things you tried before the blow help? if not i think im gonna try the 02 sensor first.

[Vegascorbin]

I did leave one thing off the list and that was Distributor. After we changed the distributor we were running the engine at about 5500 with it out of gear. After a minite or so it cut out to hte point the engine died.

When we restarted it , it had a bad knock. The next day at the track it was quiet when cold. It did start to knock as it warmed and then it never surived the 1st race of the day.

The problem actualy seemed to get worse after replaceing the plugs and wires along with the cap and rotor.

As we did the other things it got better. It was the best (but not fixed) after we changed the distributor but then blew up.

[s20700134]

Im considering replacing my ecu with one from an automatic car. what are the chances of this fixing this bug? i was going to do it to eliminate the rev limiter and speed limiter anyways(TRACK CAR) and was wondering if it would kind of kill a few birds with one stone. And,while im at it, can anyone help me out on where to find an auto ecu?

[Vegascorbin]

E-Bay?

[young-gunn]

I was gonna say go to an auto recycler (places around here charge up to $150 for a computer), but then I realized I have one in my garage. You say it's got a KA24E? If so I have an automatic computer for you. Email me at [email protected] with an offer and I'll ship it asap.

[s20700134]

yes, it does have the sohc. i'll get that email to you asap.