Please Help Me Figure Out Whats Wrong!!!!

[jeff91gsx2pt0]

To begin the car I am talking about is a BONE STOCK 1991 Eclipse GSX 5spd manual 108,000 miles.

Last summer I blew the timing belt while driving, thus destroying all the valves, ect. I recenty got the head rebuilt to stock specs, and got everything fixed. The check engine light is on, but it just turned on a month or so before the timing belt blew. So that is nothing new. The car runs, but there are major problems under boost.

first:
1st gear will NOT push full boost. The furthest I have gotten it to go is about 7psi (on the stock gauge). Also I;m not sure if its related but it also "dies off" at about 5500rpm, it just doesn't want to pull to redline. I mean it might, but it doesnt sound to good, and it isnt how it used to be. It doesn't pull like it used to, before it shit out.

second:
2-5th gear get full boost. It goes to ~14psi on the stock guage. BUT at about 4500 rpm there is a sometimes slight, sometimes major bucking/jerking in the acceleration. And again it does not pull to 7000rpm like it used to. It does not pull like it used to.

the turbo sounds healthy to me, although I am a turbo noob. Everything on the car is stock, and the only new parts are the head, water pump, and airfilter. I might need spark plugs and wires, but they dont seem too old. The other thing to mention is that other than these problems the car runs great. Starts right up, when you are not really on it, it runs fine. It is only under hard acceleration (how I like to drive) where there are these problems. Any idea what it may be? Do you think the CEL might be related to this? Any help will be appreciated. Thank you!

 

[jeff91gsx2pt0]

To begin the car I am talking about is a BONE STOCK 1991 Eclipse GSX 5spd manual 108,000 miles.

Last summer I blew the timing belt while driving, thus destroying all the valves, ect. I recenty got the head rebuilt to stock specs, and got everything fixed. The check engine light is on, but it just turned on a month or so before the timing belt blew. So that is nothing new. The car runs, but there are major problems under boost.

first:
1st gear will NOT push full boost. The furthest I have gotten it to go is about 7psi (on the stock gauge). Also I;m not sure if its related but it also "dies off" at about 5500rpm, it just doesn't want to pull to redline. I mean it might, but it doesnt sound to good, and it isnt how it used to be. It doesn't pull like it used to, before it shit out.

second:
2-5th gear get full boost. It goes to ~14psi on the stock guage. BUT at about 4500 rpm there is a sometimes slight, sometimes major bucking/jerking in the acceleration. And again it does not pull to 7000rpm like it used to. It does not pull like it used to.

the turbo sounds healthy to me, although I am a turbo noob. Everything on the car is stock, and the only new parts are the head, water pump, and airfilter. I might need spark plugs and wires, but they dont seem too old. The other thing to mention is that other than these problems the car runs great. Starts right up, when you are not really on it, it runs fine. It is only under hard acceleration (how I like to drive) where there are these problems. Any idea what it may be? Do you think the CEL might be related to this? Any help will be appreciated. Thank you!

 

[S_Ranger]

I noticed a sound like a boost leak when I accelerate but check all hoses and pipes and they are all secure. It feels like it's getting too much air in. Any ideas what it might be?

 

[eclipseGSTud]

Have you done a boost leak test yet? I had a leak because of the gasket on the throttle body. Also another leak where my SMIC and UICP meet which looked tight and secure until I did a boost leak test. Also inspect the hoses to make sure they aren't worn or damaged. After locating the leaks it should be easy for you to fix.

 

[jeff91gsx2pt0]

not to hijack a thread but how might one perform a boost leak test??

 

[PropXprt]

Here is a link that shows you step by step, how to do a boost leak test.

http://www.vfaq.com/mods/ICtester.html

Hope this helps...

 

[reveal1123]

I had a loud hissing noise when I got into boost about a month ago... turns out, my LICP was coming off slightly when the pressure raised.... might wanna check for leaks

 

[hellotbone]

This sounds like a similar problem to what i was having with my 6bolt after I swapped it in. Mine tured out to be the coils that were bad. Not saying that is the problem with yours but its exibiting the exact same problems mine was when the coils were shot. The bucking backfiring and not pulling to redline. Something to look at and test anyways.

 

[project_tsi]

This sounds like a similar problem to what i was having with my 6bolt after I swapped it in. Mine tured out to be the coils that were bad. Not saying that is the problem with yours but its exibiting the exact same problems mine was when the coils were shot. The bucking backfiring and not pulling to redline. Something to look at and test anyways.

I think a autoparts store should be able to hook up a reader and pull the CEL's and it should tell you why the light is on.

 

[missouri_dsm]

definately get the cel checked out. It does sound like it needs new plugs and wires though, or like stated above, the coils. I always go the cheaper route first(plugs then wires then coils)plus it wouldnt hurt to change your plugs. If it is your coils you will probably need new plugs anyway, they are probably fouled.

 

[project_tsi]

definately get the cel checked out. It does sound like it needs new plugs and wires though, or like stated above, the coils. I always go the cheaper route first(plugs then wires then coils)plus it wouldnt hurt to change your plugs. If it is your coils you will probably need new plugs anyway, they are probably fouled.

I didn't mention plugs and wires b/c those would not cause it to throw a CEL. Maybe your 02 sensor is bad?

 

[Defiant]

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