weird result from small exhaust change

XR4Ti / Sierra / Sierra Cosworth Discussions - Questions, problem resolution, general talk, technical tips and modifications.
SARON81
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Post by SARON81 » Fri Jun 25, 2010 5:00 pm

You can get at the dizzy hold down bolt w/a 17mm wrench through the front of the engine... or a shallow 17mm socket on a long extension between the fuel rail, and alternator. Don't touch the alt. wire with your extension. :oops:

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Post by hEaT » Fri Jun 25, 2010 7:43 pm

SARON81 wrote:You can get at the dizzy hold down bolt w/a 17mm wrench through the front of the engine... or a shallow 17mm socket on a long extension between the fuel rail, and alternator. Don't touch the alt. wire with your extension. :oops:
Done that! I now cover it with tape and then a rag.
Joe
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Post by xr super n00b » Fri Jun 25, 2010 8:51 pm

i understand, the distributer "gear" turns the rotor causing it to spark on each spark plug. rotate the whole thing and youll either retard or advance your timing(im not sure which way it spins) so then pull the top off and spin it the same degree opposite as you rotated the whole thing. but i have to check and see if i have a timing light. i think have one. that may be easier if i cant fit a pulley puller in there. i didnt get a motorcraft tfi though. i got the duralast. but its lifetime garantee.

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Post by xr super n00b » Sat Jun 26, 2010 1:29 pm

ok so i got home from class, then went to leave again. car wouldnt start. so i replaced the tfi. started right up but its still backfiring like crazy when i hit 15 psi. so im gonna head to autozone and pick up a new cap, rotor, and plugs. well see if that helps. the wires i just replaced a week ago cause one came in contact with the turbo and melted it. ill keep updating in case anyone else has this problem. the problem being the car is backfiring throught the intake when under almost full - full boost.

oh and my exhaust is not clogged. i double checked that yesterday.

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Post by xr super n00b » Sat Jun 26, 2010 2:10 pm

i also noticed that my temp is above normal, and when sitting at a red light, it jumps up a little more. could this be because of old plugs that are gaped out too much and a little bit of fuel is getting into the exhaust? i just did my water pump and i know i have no coolant leaks.

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Post by merkurmaniac » Sat Jun 26, 2010 2:23 pm

backfiring into the intake, and running shltty can be caused by many different things. Don't over look your TPS (throttle position sensor) and one thing that is rare, but can happen is a rocker arm falling off. It makes the car run all around badly. Its tuff to diagnose, but you'll feel little pulses into the intake when you grip the turbo to throttle body hose.
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Post by xr super n00b » Sat Jun 26, 2010 3:30 pm

that wasnt the issue. the car just cooled down and i replaced the cap, rotor, and plugs. the car runs SOOOO much better. no more backfiring at all. but theres still that "clogged exhaust" feel at just about full boost. i have now triple checked my exhaust. and came up with nothing. i have checked my intake, and it all looks clean, well, not spotless, but no clogs. so im wondering if when i get paid next week if i should schedule my car to get a full 3" exhaust and see if that takes care of the problem. but i dont understand why this would just happen like this suddenly. the car runs real smooth at cruising speed, and accelerates real nice up until about 12 psi. it still hits 15 but it feels like im jamming down the brake pedal at the same time. ugh when do the problems end :evil:

xr super n00b
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Post by xr super n00b » Sat Jun 26, 2010 3:31 pm

just to be safe though. what voltage should the tps be at closed and WOT

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thebronze
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Post by thebronze » Sat Jun 26, 2010 5:20 pm

Whens the last time the timeing belt was changed?? If it's skipped a tooth or 2 it'll fall on it's face under boost
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xr super n00b
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Post by xr super n00b » Sat Jun 26, 2010 5:23 pm

timing belt was done about 2 years ago. but i dont think it jump cause it pulls hard until 12 psi. if it did jump a tooth, wouldnt it dog out under any boost? oh and its an auto, isnt jumping a tooth on an auto pretty much unheard of cause autos dont downshift?

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Post by Mike McCreight » Sat Jun 26, 2010 8:56 pm

Disconnect the knock sensor.
Fill with 94 octane (or whatever you can get there that's close).
Listen CAREFULLY for detonation.
Report back!
It's not a hobby, it's an obsession!

xr super n00b
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Post by xr super n00b » Sun Jun 27, 2010 12:41 am

i never put anything less than 93 in it. so i will do that tomorrow. now comes the noob question. where is the knock sensor located?

oh and btw, tomorrow (sunday) i will be replacing the head gasket. anyone wanna give me an eta for this job. i have to have it done by the end of the day. i know its a 4 cyl and it should go fairly smooth but any advice will be noted if you can post before i get the gasket tomorrow and start.

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Post by xr super n00b » Sun Jun 27, 2010 9:06 pm

ok so i did the head gasket today. the only PITA was putting back on the oil feed line. but overall it went pretty smooth. took 8 hours. it should have taken less but i broke the 12pt 13mm socket when i was taking off the head bolts, so i had to stop and run to sears. so theres good new and bad news. good news is my head gasket deffinatly needed to be changed. the bad news is it didnt fix my hesitation problem. i did a search of where the knock sensor is and ran it before i started with it unplugged and there was no ping. heres a few pics and then 2 vids.

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like i said, definatly needed to be changed. this wasnt overflow by removing the head.
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also more good news....no piston slap
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heres the first start up, once it stayed running, it seems to run really smooth at idle.
http://www.youtube.com/watch?v=7q44YxM_h-0

and heres the first drive after burping the coolant. i dont know if youll be able to tell in the vid especially with my tach not working. but it hesitates when i hit 15 psi.
http://www.youtube.com/watch?v=dQnRDonI5oY

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Post by xr super n00b » Mon Jun 28, 2010 7:56 am

More bad news that i found out on the way to work today. The temp is still getting hot under any acceleration, and its still eating coolant. I made sure the block and the head were spotless before I put the gasket on, and I know is was sitting properly when I put it back on. Wtf. I'm getting really pissed now. This morning, the engine temp didn't drop down to normal till I got on the highway. It hasn't actually reached overheating levels yet, but it comes close. I have fire insurance, maybe ill poke a hole in my fuel line right before the rail and just drive it till it catches fire. Collect insurance money, go buy an xr with no to minimal issues and call it a day. I have run out of things to diagnose other than a cracked cylinder wall. But I didn't see anything when I had the head off. Maybe ill run a compression check this week if I can get off work early enough before my police academy class starts

SARON81
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Post by SARON81 » Mon Jun 28, 2010 12:34 pm

Is the coolant ending up in the oil, or just disappearing?

Anything under the redline is considered "ok" for temp readings (as long as it's working properly.) i had an early 86 where the gauge would climb all the way to the top before the fans kicked on... it always worried me... but that's just how it was.

Again... I'd highly recomend using Motorcraft tune-up parts. :wink:

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