Engine won't rev over 4000rpm

[LordNafe]

Hey guys,
Got it running with the new motor today. Starts and runs. Will rev up to 4000rpm, the seems to get a vacuum leak and stalls.
I'm thinking I may have hooked up TVIS wrong?
Has fuel and spark.
Any suggestions?
Cheers :)
Nafe

[Nikkojoe]

Check map sensor (both plug and vac line). It also could be tvis, but check map sensor first

[driftism]

possibly power to the tps as well... sounds similar to a problem I had before, which turned out to be the tps sensor

[Nikkojoe]

Sounds similar problems to mine, except mine was map. I was driving around for a week scratching my head as to why the car would not rev past 4000rpm. It also ate through fuel...

Turns out one pin on map sensor plug was disslodged. It can be tps, so unplug it and take it for a spin (the car will run without a tps, just don't unplug when car is running :P).

[LordNafe]

Hmmm, well I'm 99% sure the map is fine. Will unplug TPS. Will also recheck Map sensor. Thanks guys :)

[Nikkojoe]

While car is running, if you unplug the tps the car should stall. If you unplug the map sensor (either by vac line or plug) car should stall.

[JDM-086]

if the cars not reving past 4k, running super rich and wont hold idle I'm 99% sure it's your map sensor..... if the map sensor is dodgey car goes into a "get home" kinda mode, where it'll just inject an assload of fuel and wont go past 4k revs.

[LordNafe]

It holds idle :P
Would like to try and find a diagram for the TVIS system. Does anyone have one? Tried a google search with very bad results :P

[JDM-086]

it wouldnt hurt to d/c your map sensor and run the car, just to see if theres a difference.

[Akury]

I had the same problem with my blacktop once it went in the car, I checked everything, and I mean EVERYTHING. Turns out the ECU didn't like not having an input for the speed sensor, so it wouldn't let the car rev past 4000rpm . It could be something as trivial as that.

[deanoo]

check your your dizzy sounds like it's a bit retarted...

[drft86]

check the computer, mine used to do this, computer died and would adjust the timing when the engine revved

[shinny]

tps may have some internally broken contacts,
if so when you get to 1/2 or 3/4 throttle the computer can't see a signal,

but yeah could be a number of things tps, map sensor would be a good place to start

[LordNafe]

Distributor is set to factory specs, as are cams.
SHoudln't be ecu, never had a problem with it in the enar on two eyars I've had it.
I'm suspecting vacuum leak from tvis, or maybe tps as some people have suggested. MAP sensor is all hooked up correctly.

[Nikkojoe]

Unplug tps and take it for a drive. If it works better without tps connected then tps is stuffed.

[LordNafe]

Lol that's ok, I've got a few spare TPS's lieing around :P

[LordNafe]

it doesn't sound like a TVIS vacuum leak,
without TVIS hooked up it should still rev past 4, but it wouldn't have the top end power than it used to,
and it shouldn't stall,

[LordNafe]

The only reason I thought TVIS vacuum leak was ebcause i'm "fairly' sure I heard an air noise like a vacuum leak when ti hit 4k. It was getting late, I was tired and had been working on ti for a while, so I may be mistaken.
And also casue I'm not 100% sure the TVIS lines are hooked up correctly.
but I do have spare TPS's and MAP sensors, so either way, it shouldn't be a big deal

[JDM-086]

put morning fresh around the inlet mani and stuff....that should tell u if theres a leak. itll make a slurp noise

[70XIN]

Nafey, i have a list of things that could be the problem, isnt 4AGE limp mode a bitch? Anywho, my ideas, from around the web (and unfortunate previous experience) ALL of which have the EXACT same problems as yours:

-Wiring. Any dodgy connections?
-Dodgy fuel system. In that i mean, clogged lines or filter, clogged injectors, or if yours is aussie spec ... fuel lines too restrictive? Checking fuel pressure shouldn't be too difficult...
-02 Sensor farked or missing. To the point where the ECU thinks its running mega lean and goes into limp mode

Both of the above and "generalisations" in regards to similar car, the few i'd be DEFINITELY checking (and have happened to me or friends) are:

-Dizzy wired up wrong, should be

Blue wire to Black wire
Red wire to White wire
Whire wire to Red Wire

-Incorrect ignitor, or faulty. The latter happened to me, exact same problem.

-Dizzy out by one tooth. Exact same problem.




I expect much loving if any of the above are correct. Go for gold champ.

Seamus :)

Edit: And to add, i don't think its a vaccum line problem. You mentioned hissing, could it be crappy injector o-rings/fuel rail not bolted down correctly? I'm saying this, because most people have that crappy flu thing going around, might not be able to smell that it's fuel ;)

[Nikkojoe]

-02 Sensor farked or missing. To the point where the ECU thinks its running mega lean and goes into limp mode[/b]

You don't need an o2 sensor for the car. If it runs lean or cannot detect levels it will default make it rich. Ive drove around with no o2 sensor plugged up for a while and nothing was wrong with the performance (just it used more fuel).

Also as you mentioned, check wiring. Check and see if map sensor wires have continuity from the sensor to the ecu plug, and various other sensors.

[LordNafe]

Still no luck. Dicked around swapping over a different throttle body, tried a couple of TPS and MAP sensors, swapped ecu's... No love.
Didn't check anything with a multimetre though to see if it has continuity to the ECU.
Wanted it running by next weekend, but it ain't gonna happen. Think I'll get it take to Kaizen. Ant will be able to fix it :P

[70XIN]

Ignitor or dizzy

Or just take it to ant

[LordNafe]

Mmmmm Dizzy is ok. It actually revved to 7000rpm once or twice today, but only once. It's really weird. Got me stumped
Tried testing ignitor, but the only other one I had was a different one. Bugger

[SLO-030]

Havent read the whole thread but have you replaced your fuel filter?

They sometimes allow enough fuel through to rev a few times.

If you have replaced it make sure the flow is the right way

When it revs does it hit 4000rpm and then just die or does it hit like 4100rpm then die then do it again then hit say 4500rpm? In other words is it always at the same revs?

[LordNafe]

Actually, no, Haven't replaced fuel filter.
And I found out today the revs can vary a fair bit. Sometimes it'll hit 3500rpm, once or twice it hit 7000, but usually it's more around 4000-5000.
Probably should try replacing fuel filter.

[SLO-030]

Also is it just under free rev or under load or both?

I have a similar problem with a mates car but he didnt really give a chance to figure it out before he sold it because of this problem

[350hp4agte]

Also is it just under free rev or under load or both?

I have a similar problem with a mates car but he didnt really give a chance to figure it out before he sold it because of this problem[/b]
in my car the pressure in the tank caused by the fuel pump was to much try running your car with no cap c how ya go

[SLO-030]

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Also is it just under free rev or under load or both?

I have a similar problem with a mates car but he didnt really give a chance to figure it out before he sold it because of this problem[/b]
in my car the pressure in the tank caused by the fuel pump was to much try running your car with no cap c how ya go
[/b]


I dont see how that would cause any sort of problem. The fuel system runs at over 35psi anyway and if it were higher then that and getting through the fuel pump it would probably run rich.