I was driving home after getting a new muffler and Apex-i exhaust control valve put in. Everything was fine. Started messing with the ECV and it was all good. Went to a car meet instead of home then on the way home I noticed that the car would accelerate pretty aggressively. I thought it was surely a cold night and my FMIC doing what its supposed to, but no! When I got off the fwy, the car's idle started to fluctuate. Not like when a TPS is bad but more like I was giving it gas about half way. I put it in gear and the car would rev up and launch me LOL (scay tho but funny) then it got a little worse and my brakes got hard as if the car were off. Just built up pressure and wouldn't go down. I roll to my driveway and shut the car off so I dont wane the entire building population. I went to drive in and as soon as I started the car it revved instantly headed for red line. I shut it off and pushed it. When parked I noticed that the exhaust smelled like burning plastic. I popped the hood and everything looked fine.


What should I check for?

I would hate to start the car up and have it rev to redline when cold.


Thx for any help in advance


Eddie

 

Look for stuck plates in the throttle body, I think you'll find the problem there.

 

I was thinking that just now. I did remember having a sticky throttle not long ago but why would the breaks go solid? Vacuum leak?

 

Possibly a kinked brake booster line? I had mine kink doing some exhaust work one time and the brakes felt solid and did very little braking.

 

I will definitely check the lines. it's just weird that one happened as a result of the other? IDk

 

big vac leak maybe. my T2 swap was a nightmare and i had an intake leak at the block. also one of my mixing plates and air bleed valves in the center iron was melted. check that stuff. hopefully this is a good starting point. I hope it help.

P.S. my symptoms were full rev on start then blip the gas and no idle or erratic idle bc the TPS was set higher to compensate for the no idle.

while driving was major hesitation when given full throttle. but crazy power in first.

 

If you split the hose (or had a fitting pop off etc) on the line that pulls vacuum on the brake booster that would negate any helpful effects of the booster making your brakes feel like crap and and also have a huge impact on engine management.

Alternatively, the brake booster is dependant on vaccum so a stuck open throttle might work the same thing in reverse (meaning instead of brake booster issues affecting the engine, engine issues could affect the booster). This would say that because you don't have enough engine vacuum the booster can't help like it should.

Either way, simulataneous impacts to engine and brakes are a strong indicator of vacuum issues of some kind.

 

remove the mod and see if it corrects the problem. that would be the first thing I do.

 

I'll bet a bottle of brefas scotch that it's the vac line to the booster.
Second possibility would be the booster unit itself.

 

^Not gonna read all that, but check the throttle linkage. My car had a washer or bolt or something come from somewhere and lodged itself under the linkage so it was WOT all the time...scared the **** outta me. Brakes...i dunno

 

Vac leak somewhere, either in the booster or the line/fittings that feed it.

 

Its a vacuum leak. It explains the brakes,idle, and I'd be willing to bet you have an internal wastegate.

 

I bet it's the brake booster line. It'll make your brakes shitty and create a massive vacuum leak, making the engine do weird things.

 

^+1

 

Like Joel said, if the car's pegging to redline, chances are you're not going to see any vacuum, hence no power brakes.

Any luck?

 

Gonna check right now. I'm at work anxious to see what I find!

Question: What about my internal WG??? Yeah its all stock turbo and wg

 

damn eddie.. sounds like you got a ghost in your machine.. good luck my man.

 

looked at it earlier and it looks like the throttle body is getting stuck. The link holders are getting stuck and acting funny.
maybe some lubing will help???

 

lithium grease? check cable clearance? check cable motion and looseness?

 

remove throttle cable, try to operate the throttle by hand to close it first then you can start it.

as for the brakes it does sound like the booster has no vac, it might be the hose. but first you want the car started and idling without revving all the way up.

 

Word. It looks like the booster is fine but there is def something wrong with the TB... when I pull on the rod that holds both ends of the cable linkage, it slides out about an inch and get stuck open. Might have to remove UIM and TB today...


PS: Got an S5 blown one for ya soon Fris. Car sat for 3 yrs with bad seal. Still in car so no loose change will be found in it LOL

 

Fixed it! vacuum leak on the UIM... hose popped off and screwed me LOL. All i had to do is connect the line and done but instead I removed the TB and Mani haha all that work for nothing. Better safe than sorry I guess

 

I think I may have the same issue. I just got a 87 T2 and the idle is kinda jumpy, and the brakes don't seem to work too well. the guy thinks they just need to be blead, but I doubt thats the only issue. car has been sitting since 2007 so mabey thats it. I think its the booster vac. I just hope it isn't missing or broken. I need to drive it home tomarrow. and start DDing it.

 

Without a vacuum signal to the wastegate it can't pressurize and open causing overboosting. The reason your car felt all badass was because essentially the boost was jacked up. Had this EXACT thing happen to me once. That's how I knew.

 

could a vaccume leak like that in the breaks in any way make the engine flood or smoke cuz it was said that vaccume leaks make the engine do wierd things.