Fresh rebuild...SR runs like crap.

[Grambos13]

So i have a few problems...the engine ran fine before I took it out to rebuild it. (besides the low compression everything was ok) When I start the engine it idles fine. It will idle all day if you let it. As soon as I rev it or give it any gas what so ever it dosen't want to idle anymore. It will just get all lumpy and eventually die. I cleaned my iacv today with no results. The car used to do this a little before I rebuilt it but not nearly as bad. I did bypass the water line that goes through the throttle body but it dosen't seem like that would do anything accept cancle out the cold start.

Problem #2 the engine runs like crap when you try to give it a lot of gas. If I let it slowly climb throug the rpms it will pull and run smoothly. As soon as I mash on it the boost will peg at 12psi but the car seems to fall on its face. it dosen't buck really bad like a vac leak. I think it is somthing to do with my cam timing. The ignition is right on 15deg. I don't know exactly where to put the cam timing I thought it was at 10 oclock intake and 12 oclock exhaust but I don't know if thats lining up the dots or the dowl pins.

Please help me guys I've been batteling this for weeks now and Its makeing me not be able to sleep at night

[Silvia007]

What did you do in terms of a rebuild? How did you setup the timming exactly?

[Grambos13]

rings, bearings, turbo, seals....I set the cam timing with the intake dowlpin at 10oclock and the exhaust dowl pin at 12oclock...Not sure if you set it by the dowl pin or the dot on the gear. and the ignition timing is at 15 degrees...

[Nismo_Freak]

Dot on the gear lines up with the colored link in the chain.

Pull your injectors back off and see if you have a leaky o-ring.

[Silvia007]

Should be two same color links on the chain and one that is of different color. The one of the different color is the one on the crank shaft sprocket. With the crank shaft at TDC, you line up the dot that does not have a match on the crank shaft sprocket. Once that's done, line up the two matching links with the dots on the cam sprockets without turning the crank shaft. Then there's the deal with the CAS.

Are you using a timming light to see that the timming was at 15 degrees using the proper steps as stated in the manual?

[Grambos13]

yes I am using a timing light and it sucks because my new timing chain does not come with any different colored links. they are all the same so I need something more exact...

[jdm_master_X]

it may have something to do with compression. did u install the piston rings correctly (ring #2's open end should be 180 opposite of ring #1, and the oil ring's opening should resemble a "W" not an "M" when together).

did u happen to do any valvetrain work as well? hopefully the valves havent been overtightened.

[Grambos13]

I'm not sure about the rings becuase my friend did those but I know he installed them according the the instructions that they came with. Would I be able to tell with a compression test? The only valve train work that I did was changing out the valve stem seals. Not sure how this could effect anything but what do I know...

[jdm_master_X]

well the seals might not be on properly or the valves arent seated properly in the head.

well i mean, i would say, if this rebuild was the reason for its poor starting, u really should consider removing the SR and inspecting it again. as long as u know u are getting air, fuel, and spark, then proceed to test it as follows:

for inspection-compression test -cylinder leakdown test (to see if valves are opening and closing properly)

for rebuild-lube the cylinder walls-inspect the piston rings-inspect entire valvetrain

let me look through my notes just one more time and ill let u know exactly what u can do. ill get back to you soon.

[Shift_Oversteer]

If you have an sr fsm check out the timing chain instructions. There should be two dots on your cam gears, if you have your chain set up properly on your gears you should be able to count (24?) links between the two dots...

[Grambos13]

I'm going to pull the valve cover off tomorrow and check out the timing on the cams again. I'm also going to test the voltage on my z32 mafs because I noticed today that when I disconnect the plug it dosen't want to surge as much as it does when connected. Although it still is doing something because when it is disconnected it will not rev over 2200 rpm. I'm pretty confident about the work that was done on the engine becuase my friend that helped me is a skilled mechanic and he taught me a lot of little things I didn't know through out the whole build. I'm going to try a few more things before I go ahead and take it back out. Thanks for the help. I'll keep you guys posted as of what I do/find out. If you guys have anymore ideas please throw them my way.

[fullthrtl_tech]

yeah the maf is a good route to go, because you might have missed something simple putting the engine back in, maybe a pinched wire. You can single out the rings with a compression test. Do a dry one then a wet one. Just put a little oil in the cylinders to check compression because the oil will seat the rings. If you have access to a leakdown tester try to use that. Put the engine at tdc on compression stroke and measure your leakage. Then listen for the escaping air. That will lead to the problem component. An easy way to check for a valvetrain issue is hook up a cheap vacuum gauge you can get from autozone to a good known vacuum source. If the needle doesnt hold rock steady you have an issue. But none of these things are worth chasing until you have ruled out elec. and when its cutting out see if you have injector pulse with a noid lite, if your friends a tech he should have one.

[Grambos13]

yeah I was going to try the leakdown test and the compression test after I get my wiring harness back in. We took it out the other night to inspect it and clean it up a little. I feel like I am allready making some headway by the looks of my harness before we did the work on it. It seems that I never even had the iacv wire hooked up by the battery tray. As for the vacuume I think the valve terain is ok because my boost gauge reads a steady -20psi of vacuume at idle.

[fullthrtl_tech]

sweet man, sounds like u are on the right track. U jsut gotta hunt **** down. Good luck man,