New XR4Ti owner: questions

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Longitudinal
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New XR4Ti owner: questions

Post by Longitudinal » Thu Apr 08, 2010 5:00 pm

Hello, all. I just bought my first XR4Ti yesterday. I am liking the car a lot and am glad to have a solid midwest example after a short quest to locate one.

The one I bought seems to have been well cared for over its life until recently falling into the hands of a "tunner" (yes, intentionally misspelled with two ns) who had a muffler shop build an inexcusably ill fitting and badly designed cat delete exhaust and a Pep Boys style cone filter. Believe me: this stull will be fixed. I will build a proper exhaust for it and will get this car headed in the right direction with a T5 swap and the Supra rear diff mod--among many other things.

The first thing I need to address is that the car needs both inner tie rod ends; both are rusty metal-on-metal and quite loose.

So, the first question is: what are good, reliable online sources for parts?

I am not at all new to the world of German cars, as I have been up to my neck in Audis and VW for ten years now. If my normal online VAG parts sources such as autohausaz.com and germanautoparts.com are good Merkur sources, then all the better.

The second question is: is there a common reason for a grumpy idle? It hunts a bit, occasionally rising up to 1400RPM or so before settling down to the usual 800 or so. When idling at its customary RPM, it has a rather, how should I say it, "top fuel-ish" idle. It never stalls, but I know that it can idle like glass because I drove another one before buying this one, which did nothing well but idle, and it did that perfectly. Somebody has replaced the ISV, possibly trying to solve this problem. I will check the usual suspects--plugs, wires, cap, rotor, compression; but I thought some BTDT advice might save me some time.

Thanks, and I look forward to learning a lot about this new car and new direction in my automotive life.

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Ray
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Post by Ray » Thu Apr 08, 2010 6:50 pm

online parts sources:

BAT
mc2racing
rockauto
rapido
merkur depot
merkur parts midwest


Idle - check your TPS setting. There should be a how to around here, it's pretty easy. Stock BTDC for manual = 13* with the SPOut unplugged (yellow wire off dizzy). Auto = 10*.

Enjoy your new ride :)
-Ray
1985 Ford F150 - Tow Missile
1985 Merkur XR4Ti -#141 CP "Miss Daisy"
2005 Subaru LGT
http://www.cartct.com

Longitudinal
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Post by Longitudinal » Thu Apr 08, 2010 8:01 pm

OK. Thanks. I will check that stuff and look for the how-to article with a resistance reading to shoot for.

Also, this car has 57K actual miles and no tool marks on the O2S. With the bad gas mileage I am estimating from my trip home with the car and the sluggish throttle response, I am guessing that an O2S would not be a bad move, as it may be original.

It's MT, by the way. As soon as I can, it is going to have a T5. I have the T5 and the flywheel and bell housing. I just have to get the Supra diff conversion bits. I am guessing that having a good shifting transmission and an LSD would make all the difference--oh and more precise steering after I replace the worn out inner ends.

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Ray
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Post by Ray » Thu Apr 08, 2010 8:31 pm

Why a supra diff?

While you're in there for the front end - get the mc2racing nylon steering rack bushings. They're well worth it. And not that hard to install.

For the TPS you're looking for voltage, not resistance.
-Ray
1985 Ford F150 - Tow Missile
1985 Merkur XR4Ti -#141 CP "Miss Daisy"
2005 Subaru LGT
http://www.cartct.com

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SvoSierra
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Post by SvoSierra » Thu Apr 08, 2010 9:08 pm

Other board members are sources for parts too! 8)
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Post by turboplz » Thu Apr 08, 2010 10:14 pm

Some cars just never want to idle right even after setting the idle and tps correctly, I think it may be due to faulty wiring over the years of heat and oil exposure.

Another thing to check is all your main engine-chassis grounds, these can create issues that you wouldn't expect such as you're describing. I've owned 8 Xr's over the years and pretty much every single one of them had corroded/missing engine grounds. I would replace these with some 2 gauge wiring and then do the "Big 3" that many audio gurus do. This will help get the most out of the weak stock charging system and help cure many little issues that may or may not be posing problems.
Jason

89 Xr4ti..."Bronze Turd"...long term project/current garage queen

2014 Focus ST

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Post by hEaT » Thu Apr 08, 2010 10:31 pm

One thing I noticed today setting my TPS. It jumps about .1v when the car is started so if I set it perfectly when the car is off, as soon as I start it, it's reading too high and it high idles and hangs.
Joe
1985 Nimbus Grey XR
2017 Ford Focus RS

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Post by Longitudinal » Thu Apr 08, 2010 10:54 pm

demonfire wrote:Why a supra diff?
Because there is a bolt-up kit available. Because it is a strong differential with a good LSD from the factory and I abhor open differentials on any RWD car, let alone one that will be making respectable power eventually. Because I have to have a driveshaft made when I go T5, and this is the time to make ALL drivetrain changes I anticipate the need to make.

I will check out the bushings. I want to tighten up all of the bushings and go nylon, delrin or polyurethane everywhere I can. Is there a complete bushing kit out there?

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Post by hEaT » Thu Apr 08, 2010 11:24 pm

Bushings:

http://www.mc2racing.com/products/xr4ti ... index.html

Add the steering rack bushings and you're set.

As far as the diff, look into this as well:

http://www.mc2racing.com/products/xr4ti ... index.html
Joe
1985 Nimbus Grey XR
2017 Ford Focus RS

Longitudinal
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Post by Longitudinal » Fri Apr 09, 2010 11:29 am

Wow. Like I told my friend yesterday, I won't have to be nearly as creative in finding ways to spend money on this car as I have been with my Audi. At least stuff is available.

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Post by deathbypsi » Fri Apr 09, 2010 2:27 pm

We need some pix!!

And MC2 racing is the only place to go if you need chassis parts!
Brian R.
86 SVO

Longitudinal
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Post by Longitudinal » Fri Apr 09, 2010 2:55 pm

deathbypsi wrote:We need some pix!!

And MC2 racing is the only place to go if you need chassis parts!
Best prices? I was a bit sticker shocked by the price of the bushing set, but I have never bought a bushing set like that before.

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Post by SvoSierra » Fri Apr 09, 2010 3:05 pm

But those bushings will transform the feeling of the car! :headbang
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Post by TommyT » Fri Apr 09, 2010 3:30 pm

hEaT wrote:One thing I noticed today setting my TPS. It jumps about .1v when the car is started so if I set it perfectly when the car is off, as soon as I start it, it's reading too high and it high idles and hangs.
Yeah I've noticed that as well. I always set the TPS to ~.92-.93v with the car running and then turn every accessory I can think of on to make sure that the voltage never goes above .99v at idle. As soon as the computer sees 1.0v it thinks the car is at part throttle operation which causes the TPS to "fight" with what the VAM is telling the computer.

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Grayson
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Post by Grayson » Fri Apr 09, 2010 5:26 pm

Best prices? I was a bit sticker shocked by the price of the bushing set, but I have never bought a bushing set like that before.
Careful when you're comparing an mc²racing bushing kit with other kits. For example, the rear and complete kits include a polyurethane differential mount, which is not included in any other kit on the planet. Also, the STA bushings are machined nylon, rather than cast polyurethane. Plus, you get Powerflex bushings, which are better than all the alternatives out there.

We don't have junk available, so the prices may seem high at first glance, but the truth is you shouldn't find what we carry for a lower cost anywhere else...not even online.

I'm between Dayton and Cincinnati if you ever want to swing by, BTW.

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