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Discussion Starter #1
So... where to start... I've owned the Z for just over a year now. Bought it Dec 31st 2004 with 130k miles and no problems. Hrm... first to go were the spark plugs. Found they were Bosch copper plugs. Eww.. Replaced with PFR6b-11b's. Then my fan clutch went. Replaced with CSK cheapie.... That one went really fast. Tried another, it went... and so did the waterpump. Replaced the fan clutch with an E-fan, as I was getting to the waterpump, I noticed that the 120k service had not been performed(previous owner lied). So, I did the whole 120k service(adjusted TPS, did regular tuneup stuff). Car was running good after that.

Next to go... turbos. :( But other than 0psi boost, the car runs fine... so I keep driving it. Next is a hole in the clutch slave line. Then the clutch. So, I replaced the line with a SS line, replaced the slave cyl., upgraded the clutch with an RPS Max clutch with Street Disc(and all the aftermarket upgrades associated with the clutch).

When I get it back on the road, I notice a weird miss/stumble. Very intermittent. It gets worse, and I decide to tackle the injectors. I find 3 out of spec, and all the connectors corroded. I snag 3 of Zedx's spare injectors, clean my fuel rails, clean all the injectors, clean the filters, replace the pintle caps, replace upper and lower o-rings and insulators. Get everything back together... still having issues. So I replace all my injector connectors. Runs AMAZING. Just a clean buttery smooth idle.

Then I start having issues with a high idle. I adjust the IACV, then find that my coolant temp sensor is bad. I replace that, and the connector. Check my knock sensor, that's bad too, so I bypass it(no detonation.), then I decide to replace my IACV connector too for good measure. Idle is now smooth, and low(around 650rpms and ultra smooth). 1 week later, I install an Ashspec ECU and boost jets.

Still runs fine, then 2 days later, I've got a really bad hesitation and high idle. The idle is back up to 1,100rpm's, and as soon as I touch the gas, the idle drops 350rpm's then builds back up. I remove the air regulator and test it, works fine, clean the connector unit and reinstall. Not fixed.

1 day later, it now does that same drop in rpm's no matter what the rpm's, as long as I let off the gas, then apply gas again. I drive home, and get to work again. Battery cables look nasty, who knows maybe I have a bad ground, so I replace both battery cables. Next up are the TB's. I clean them thoroughly with WD-40. While I'm at it, I adjust the TPS again, set it at .43v. Put everything back together, and now it won't run. It takes forever to get it started, and it runs like crap... barely runs at all.

Pull the plugs, they are all BLACK. I clean the plugs, pull the AshECU and replace with original ECU(I received it back with the upgrade), pulled boost jets, started, runs a bit better. I replace the plugs with ZFR6F-11's(copper equivalent, reccomended by Ash, and several others). Car runs, but rough, getting better though. Turned it off really quick so I didn't ruin another set of plugs. Seemed like part of it was a vac. leak, so I tested for that, and looked around. My IACV leaks a little bit of air, but not much.

Next up vacuum hoses. I replaced all the small vac lines I could get to. The ones on the two units next to the battery. The small ones at the back of the engine. The ones on the drivers side and the ones connected to the TB's. Then, I replaced the larger vacuum hoses(1/4"). Took me forever since I had to pull the drivers side hard boost pipe and the flexible intake pipe to get to the vac lines in that area.

While I was at it, I did a better job relocating the PTU wires. Well, I just started it up, fired RIGHT up... no more fluctuating idle. But it sounds like it's missing again, just like before I worked on the injectors. I pulled each coil pack, and each time the rpm's dropped. Still had a problem with the RPM's dropping when I touched the gas, so I disconnected the grey harness from the TPS. Idle raised a bit, but now, the idle doesn't drop when I touch the gas. So... I'm guessing that the .43 volts is not working out on my TPS. Original specs were between .4 and .5, with the TT.net writeup stating that between .4 and .45 was a better range.


1. So... where should I try and set my TPS voltage to cure that funky hesitation?

2. What should I be looking at for the intermittent miss?

I've done all sorts of reading, etc... I'm to the point where I'm running out of ideas. Should I replace my CAS? PTU? Oh, when I replaced the injectors, I pulled the CAS, and spun the shaft and each injector fired. So it 'appears' that my CAS is good... or is that a bad assumption?



Post Edited (Jan 24, 3:36pm)
 

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Sorry to be a "nudge" but your posting is nearly impossible to read. Maybe put in some paragraph breaks every few sentences?

Makes us readers a bit more motivated to read the thing and comment.
 

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Discussion Starter #4
Usually I do... but I had no idea where to put the breaks that made sense... Oh well, I'll just break it up with no rhyme or reason to the position. :p
 

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Discussion Starter #7
"Wow that's a story and a half..."

Well, too often people don't give enough information, someone tries to help, only to have the person say, Oh, I've already done that. Heck, there's still a possibility that I'll say that too! Kinda hard to throw everything out off the top of my head. I think I've done other stuff too... Oh, I've hollowed my cats, installed an intake.... more... can't remember.



Post Edited (Jan 24, 3:38pm)
 

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Sorry. I typed a nice response but hit backspace to edit and it went back on the HTML page instead.

So more consice.

1. Great paragraphs, good read, the right info.
2. Run codes again.
3. Fix the IAV by replacing it or jbweld - tt.net write up.
4. Switch out the TPS with a friends.
5. Grounding kit.
6. Disconnect neg. battery cable after running codes and leave off overnight.
7. Good luck.
 

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Discussion Starter #10
No codes (again). Will do on the IAV rebuild.

I'm definately thinking of doing a grounding kit.

I'm really starting to wonder about my TPS...

So, I went back down, started it up, let it warm up. Shut it off, disconnected the grey connector from the TPS, readjusted the TPS to .48v(MaxDoc advised someone else to use .48v). Attempted to start it back up again, won't start. I sit there and the thing just cranks and cranks... but it won't start. The TPS was the ONLY thing I touched.
 

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Discussion Starter #12
Well, it's .480v right now. This is sooo stupid. I think I've driven my Z once this quarter... Maybe twice.
 

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Discussion Starter #13
Took off the TPS, inspected it and the wires, reinstalled it, set it to .479v. Still won't start. Either no fuel or no spark. Can the TPS prevent one or the other, or too much fuel... something that would prevent it from starting? I'm getting REALLY frustrated.
 
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