car is redlining when i start it

[Jordan249]

SO, i had some fuel problems and found out my spacers were bad so i replaced it. at the same time I also replaced the the throttle body with a q45 one (this one was already attached to a freddy manifold so i just swapped both). So now, whenever I turn the car on, the car starts up and just straight to redline for some reason. I checked the throttle cable and it's tight, but not tighter than it should be. I'm guessing it could be the TPS sensor? I'm gonna try and see if that's it, I just wanted to know if you guys had any other idea, because i dont see why it would be doing this.

[shiftdrift]

did you check to see if it's opening the throttle body? i know you said you checked the cable but look harder.

[Couped_up'd]

You might have a air leak in the intake?

[murda-c]

if you have cruise control make sure that cable isn't hung up, happened to my car before after i took off the throttle body and put it back on.

[Jordan249]

You might have a air leak in the intake?

even if so, it shouldn't rev it up to 7k and stay there....

did you check to see if it's opening the throttle body? i know you said you checked the cable but look harder.

if you have cruise control make sure that cable isn't hung up, happened to my car before after i took off the throttle body and put it back on.

ill have to see. ill check tonight and post an update.

[Jordan249]

So... I checked the cable. I can manually open the throttle body all the way, so the cable is not that tight. Also, one of my bolts for the manifold is stripped but I don't imagine that would cause it to redline. So, I took the TPS sensor and tested it. It read .046 volts!!! it's supposed to be at .45 volts! So, I think I found my problem, the problem is, is that I cant really adjust it all that much. What do I do in this position?

[Jordan249]

bump. how do i adjust it that much?

[4x4le]

no way its the tps causing this. You may have a tps issue, but the engine cannot rev that high without air allowing it to.

Your engine is getting air from somewhere. Find out where, fix the problem.

check your idle screws on your tb.

[Jordan249]

no way its the tps causing this. You may have a tps issue, but the engine cannot rev that high without air allowing it to.

Your engine is getting air from somewhere. Find out where, fix the problem.

check your idle screws on your tb.

can the idle screw really give that much? must be the manifold.... ill retap that whole and take it from there.

[slider2828]

o it can't... its most likely a busted fast idle mechanism...

Also did you take off any coolant lines on the intake manifold and didn't run them correctly? What motor? Check the factory service many, but must likely your fast idle cam is stuck or wide open....

[4x4le]

how couldnt it? Im not talking about the idle screw on the iacv im talking about the little set screws on the tb.
90mm tb on a 2L engine...... it dont have to be that far open to provide way too much air.

My n15 tb can make my engine bounce the limiter with the set screw set wrong. I know because it did the first startup after I installed the tb and that was the issue.

[slider2828]

you talking about the throttle wheel stopper thing? it would have to be far open.... I mean pretty far open... its unlikely but oh wellz

[4x4le]

It really dont have to be that far out. Im not trying to argue or any of that nonsence, I just really believe in my point.

Look at the surface area difference of the butterfly on a q45 and a stocker. q45 tb's are massive and that is why I dont like them on small engines. There is less throttle control. http://i300.photobucket.com/albums/nn40/4x4le/misc/1016081932.jpg


edit: also look how long that throttle stopper screw is on one of these

[DataXUnknown]

Thats what you get for buying a freddy manifold.

Sounds to me like you connected some hoses wrong somewhere. Oh and make sure your MAF is working right (I know that wouldn't cause this but it's always good to check a MAF, plus someone is bound to come in and be like "omg dude check your maf")

[Jordan249]

Thats what you get for buying a freddy manifold.

Sounds to me like you connected some hoses wrong somewhere. Oh and make sure your MAF is working right (I know that wouldn't cause this but it's always good to check a MAF, plus someone is bound to come in and be like "omg dude check your maf")

It was running fine before. I had some idling problems and I remembered that one of the screws was busted on the iac and wasn't closing right so i took off the manifold to get to it. I'm pretty sure i hooked the lines up correctly. Got the main one in the back hooked up to the brake booster. 2 coolant lines running through the iac, one vacuum hose running from the bottom center of the manifold to the valve cover, then two main vacumme lines running to the main vacuum line and the other one to the map sensor. So, I don't think it's the maf since I don't have one lol. What'll I'll do when I feel a bit better is completely take off the throttle cable and see if that works. I got pinned against the garage by my own car and my legs got pretty messed up by the intercooler. My roommate was starting the car while i was looking underneath the hood and i asked him to turn it off and it was still in gear and well yea.... lol

[d3m14n]

sounds like you connected the throttle cable to the cruise control side of the throttle pulley... double check which pulley you have it on...

[Jordan249]

sounds like you connected the throttle cable to the cruise control side of the throttle pulley... double check which pulley you have it on...

sounds good. I'll check it out once my leg heals up a bit. maybe tonight.

[slider2828]

LOL.... take a picture all around that area... you describing it to us ain't doing us any good...


take pictures of iacv, throttle body, throttle cables, vacuum hookups, and coolant hook ups... only way people can help.

[army240]

Is your car a Toyota?!? haha just kidding!

You need 2 things to red line a car... lot of air, and lot of fuel.

Here's some basics :

When you press the fuel pedal, you are controlling the amount of air entering in the engine. Your MAF is always calculating the amount of air getting the engine, VIA THE PIPING. If you got an air leak between the engine and the MAF, your car will run lean, because too much uncalculated air will get to the engine. If you have an air leak in the manifold, it could result in low vacuum too. So as I said, you need to have a lot of air coming in... and I mean Calculated air! If your throttle plate is open, or IACV to much open, the engine will then calculate the airflow, and inject too much fuel, so it will redline.

Ok now, I just read the thread about not having a MAF(I guess you run D-Jetro?!?)

For a MAP, it's a little different. It tells the ECU how much pressure there is in the Intake. You also need to have an IAT too, because colder air is more dense than hot air. Having a low vacuum in the manifold(open throttle plate, cracks, leak, then more air), the ECU will inject more fuel. If the engine is not receiving that air(caused by a bad MAP sensor), the engine will run rich, too much fuel will be injected. It's that simple.

Ok, how did you checked your TPS? Did you open the throttle plate while your DMM was connected to see if the value is changing?

Also, if you are running D-Jetro, do you have a PFC Controller? You can monitor the voltage with this, so you know if it's ok. Or get someone with a Datalogit, so he can log the TPS, IAT, MAP, etc... value with the RPM!

Anyway, hope that help!

Frank

[s!lv!a]

Sorry to dig a thread from the grave, but I figured I'd rather recycle a thread rather than make a new one. Was this issue ever resolved? I'm having the same issue and from what I've read and searched a few other people have had the same problem and I've yet to see a fix other than people saying "vacuum leak" or "throttle open".. I've read something about the Q45 TPS needing to be calibrated to the RB25 ecu and I'm definitely thinking this has to be something with the sensor being that the RB25 I have in question ran absolutely perfect with the stock manifold/throttle body and after switching to greddy manifold/q45 tb is when the problems started and now when I start the car it jumps straight to 6k rpms and sticks. I've unplugged the MAF as a safety net to keep revs down to 3-3500 rpms just so I can diagnose the problem and look for leaks/etc. I initially thought vacuum leak because that's the obvious, but I have absolutely NO vacuum leak, the throttle body is 100% closed, and everything is connected as it should be. If anyone could enlighten me on what other possibilities are out there, by all means give me suggestions because I'm running out of ideas and I want this car back on the road..

[s!lv!a]

UPDATE: Removed the "high idle" spring from the Q45 TB so that allowed the TB to close more bringing the revs down fluctuating between ~2200-2500 with the MAF unplugged and revs to around 5k with it plugged in. I've adjusted the idle screw all the way out in hopes of fixing the problem but no dice..

[SurfGuruJeff]

Hmmm... that's funky.

[Jordan249]

Mine ended being the break vacuum house that goes into the back of the intake manifold.

[Om1kron]

I don't see a problem here, saves you from needing to hit the gas to do a burn out of of parking spaces.

[s!lv!a]

Mine ended being the break vacuum house that goes into the back of the intake manifold.

Mine turned out to be the big port under the manifold by the AAC.. I felt pretty stupid once I realized this.. haha, I still have a high idle (~1700rpms), but I'm about 90% positive that theres a leak where the manifold meets the head. I bought the car with the motor and manifold already installed so I'm still working out all the kinks.. Thanks for the help!

[krookedstyle]

I don't see a problem here, saves you from needing to hit the gas to do a burn out of of parking spaces.

I like your way of thinking that sounds right...:rawk: