won't rev above 4000rpm

[hunging]

Thanks to all those that helped with my previous problems. I think I'm down to my last problem for this conversion (sw20 gen2 3sgte --> gen3 3sgte). My car won't go over 4000rpm.

My first suspect is the ignition system. After reading a few mr2 forums I've changed over to a 5sfe Camry ignitor and it's made no difference. I'm using a set gen2 distributor rotor and cap which is about 5 months old so that shouldn't be the problem. Ignition cables are about four months old. I'm using the same ignition coil as before and it was fine before I took out the old engine.

Haven't tested the fuel system yet but again I'm using the same parts that were running fine prior to the conversion.

Other suspects:
1. incorrect wiring? but what could make it run fine up to 4000rpm?
2. blocked cat? don't wanna go there yet.

It would be good if someone could point in in the right direction.

[Billzilla]

Check the ECU for error codes.

[hunging]

No codes..

[hunging]

An update:

The fuel pressure was measured today and it was 400kPa (~60psi) at idle. Which is ridiculously high, right? Disconnecting or connecting the vacuum hose made no difference. So I'm guessing the fuel pressure regulator is gone.

I'll give more detail on the rev. The engine would hit a wall at around 4000rpm during WOT. If I was to apply around a third throttle it will slowly but eventually get up to around 6000rpm.

This leads to my theory. There is no doubt the engine is running rich like a slut. During WOT it becomes flooded thus not being able to go past 4000rpm. If light throttle is applied it's rich but not flooded so it slowly climbs up the revs range.

Comments and opinions?

[Billzilla]

Yep, it should be more like 38 psi at idle - or thereabouts.

[oldcorollas]

wires on the reluctor pickup are backwards?

try swapping around and see if it has an effect

[hunging]

Will get fuel pressure fixed on monday.

Would a problem with the reluctor make the car run ridiculously rich? Or would it just misfire?

[oldcorollas]

if it is totally misfiring, there will be a lot of unburnt fuel coming out exhaust (and melting cat)
reluctor just commonly makes the ECU fire spark at wrong time, or make it difficult for ECU to detect the pulse... and makes it hard to rev above about.. 4000rpm...

but fuel pressure is a bit whacky, and a seperate issue...
if you are using all same parts (pump, injectors, fuel reg) then it seems odd that it sould suddenly cause issues...
blocked or kinked return line? vac line to reg doing odd things?

[hunging]

Update: It seems your suspicions about the fuel pressure issue have been well founded. I am using all existing parts except for the fuel rail and the fuel reg which came with the gen3 engine. But testing the return line showed a pressure of over 400kPa . Even compressed air wouldn't get through and the tube just kept popping off. After a bit of fiddling around with the hoses whatever it was disappeared and my fuel pressure came back down to 200-300kPa.

Now: The rev limit doesn't seem to have improved at all. The same symptoms are showing with puffs of black smoke at 4000rpm during WOT. Only this time there isn't evident black smoke at idle and the puffs during WOT are slightly less. The car does seem a little stronger. Rev limit is still the same.

My thoughts: I think oldcorolla's suggestion is becoming more likely seeing dropping the fuel pressure hasn't even raised the rev limit. I have checked the connections according to the BGB and the wiring to the distributor seem fine to me. I have checked the resistances between G(-) and G1, G2 and NE and they all checked out according to BGB values.

So I have two paths:
1. Replace the whole distributor with my gen2 engine which was working. I'm pretty sure the distributors are the same.
2. Continue to assume it is a fueling issue and deal with my injectors with the whole ultrasonic thing.
Which should I try first? and sorry for my long winded post

[Kyosho]

Standard ECU?

[hunging]

very standard

[Kyosho]

Is the ECU from the Gen2 or 3?
Is there a difference in cam/crank sensors?

[hunging]

I'm using the gen3 ecu. Gen2 loom has been rewired on the ecu side to accommodate for the different pin layout. From what I've seen and read the distributor is exactly the same.

[Kyosho]

Check your wiring.
You may be getting a signal from a sensor breaking down.

Try as said above with the reluctor.

[Kyosho]

Also, if it's blowing "black" when it's limiting, it's most likely not a fuel issue as such.

Also, have you tried putting in some new spark plugs?
Alot of engines break down spark on high RPM once on boost. Backing off and they'll cruise to red line.