Jeep Wrangler Forum

Jeep Wrangler Forum (http://www.wranglerforum.com/)
-   YJ Tech Forum (http://www.wranglerforum.com/f218/)
-   -   Won't run right after State Inspection (http://www.wranglerforum.com/f218/wont-run-right-after-state-inspection-203850.html)

punchesdfw 12-06-2012 07:47 AM

Won't run right after State Inspection
 
I have a '95 YJ w/ 2.5l 5-Spd. - I Took it in for the Texas State Inspection. It was running fine when I drove it in, but it wouldn't start after they pulled it off the machine. This is the second inspection in a row that this has happened.

I pulled the battery cables for several minutes to reset the ECU and it limped home, backfiring and sputtering with absolutely no power. If you accelerate very slowly, the engine will respond, but it you drive it normally, it bogs and backfires.

I was thinking it might be the TPS, but why would that go bad when inspected?

Any ideas?:banghead:

C.L. 12-06-2012 08:03 AM

The dumbasses at those places usually redline it on the rolling road machine when testing emissions. It's possible they drove the TPS past the range that the ECU has adapted to, and it flipped out with the new input. If it thinks you're constantly at either WOT or idle, it may be messing with your fuel/air mix.

Takes something like 8 hours for a true reset after pulling the negative battery cable. Try leaving it off overnight, then replacing the TPS if it's still acting up.

punchesdfw 12-06-2012 08:16 AM

Sounds good. I'll pull the cables right now and let it sit all-day.

It seems like every time somebody other than me touches any of my cars, they screw-up something.

denisbaldwin 12-06-2012 08:17 AM

Quote:

Originally Posted by C.L. (Post 3073034)
Takes something like 8 hours for a true reset after pulling the negative battery cable. Try leaving it off overnight, then replacing the TPS if it's still acting up.

This. I'd leave it unplugged at the battery overnight. The last few times I had electrical problems, I did this and they went away.

Denis

punchesdfw 12-06-2012 08:42 AM

Thanks. The battery is disconnected. I'll wait until 5:00PM which will be well over 8-hours and I'll see what happens.

Xpress 12-06-2012 11:45 AM

I'd have gone back and politely explain the situation to them, and explain to them that because they may have potentially damaged the vehicle, that you will hold them liable for making the necessary repairs.

punchesdfw 12-06-2012 06:22 PM

Well, that didn't work. I'll try the TPS now.

RednekYJ 12-06-2012 08:29 PM

it does not take 8hrs for a reset. That is nonsense. Take the cables off the battery, wait a minute or 2 then touch them together.

2xs 12-06-2012 09:28 PM

Its an inspection, they inspect, they dont ever red line your vehicle. Their test is pretty rough there, alot rougher then the Cali one I do daily.
IM240 will bring out a bad or weak component quickly. Check codes (I believe Key on, off 3x then on and watch the flashes), Dont just randomly replace stuff, chances of the TPS going bad are rare, thast the same engine used in multiple vehicles, if there was a known issue, the test would be modified for those and the tech would know it, unless he is a complete dumbass, or a new tech.

Get back to us with the code, hopefully whoever told you to disconnect the battery didnt cause you to erase the code, people are too quick to erase/clear computers before checking the data first....

Xpress has a good idea too, since they are in the auto business, they SHOULD understand that stuff doesnt always go the right way, and might work with you to come to a conclusion, however they will refuse to be responsible for anything that was damaged due to wear and tear, or neglect, and ALOT of stuff can be put into that category for a vehicle this old (wear and tear, not neglect)....
If they try to go the neglect route, I hope you have service records, because it becomes your word against theirs....

punchesdfw 12-06-2012 09:51 PM

Problem is, non of the reputable shops in my area will touch an inspection on a '95 or older vehicle. This place is pretty ghetto and it's pretty clear that they aren't going to do anything. I replaced the TPS and it actually runs a lot better, but it still is down on power and backfires occasionally. I'll check the codes and see what I get.

punchesdfw 12-06-2012 10:10 PM

Checked the codes 12 - Battery Disconnected, 33 - C/C Circuit open (I don't have A/C), 55 - End of codes. No joy!

punchesdfw 12-07-2012 12:43 PM

1 Attachment(s)
After some more research I thought it might be the Ignition Coil, so I replaced it. No better. I did notice this new development under the hood. I have no idea where this ground wire goes. Maybe they removed it? Where does it go?

jokerchief462 12-07-2012 01:09 PM

The ground strap should be attached to the engine one the cylinder head and to the chasis on the firewall.

rykemc 12-07-2012 01:28 PM

Quote:

Originally Posted by punchesdfw (Post 3077842)
After some more research I thought it might be the Ignition Coil, so I replaced it. No better. I did notice this new development under the hood. I have no idea where this ground wire goes. Maybe they removed it? Where does it go?

I bet that is your problem right there sir.

punchesdfw 12-07-2012 01:42 PM

I looked some more and found where it went. Firewall to hood. This is driving me crazy!

rykemc 12-07-2012 01:54 PM

Do you have a ground strap coming off the back of your motor?

punchesdfw 12-07-2012 02:24 PM

Yep. Another one coming from the engine to the same ground location on the firewall. It idles fine and it revs fine, when not under a load. But, when you accelerate, it's done on power and backfires. I'm tempted to take a Sawzall to the Cat and see if it's the problem. It's not throwing any codes, so I'm just guessing.

In the past year it's gotten, timing set, Water Pump, Exhaust Manifold, O2 Sensors, Plugs, Wires, Cap, Rotor, MAP Sensor, TPS, Ignition Coil, Fuel Relay, Fuel & Air Filters...

2xs 12-07-2012 06:03 PM

Check the vacuum line to the MAP sensor, should have full manifold vacuum there.

Do you have a way to check voltage ( a meter) ?

punchesdfw 12-07-2012 06:24 PM

I unplugged the o2 sensor to see what would happen and now it won't even start. WTF? I had vacuum at the MAP sensor and yes I can check voltage. Any ideas?

EDIT - I pulled the battery for a few minutes & now it starts again. Still runs like crap, but it starts.

pocketpistolpete 12-07-2012 07:49 PM

Keep it simple man. Run through all the vacuum lines first and check for minute cracks/splits or cuts. Spray Carb cleaner on them and listen for engine rev if need be. Then Pull plugs and check for fuel being dumped on them and fouling. After that, inspect your sensors again then move onto the cat being clogged....after that, hell man idk you beat me.

pocketpistolpete 12-07-2012 07:51 PM

Afterthought, they may have rattled up sediment in your gas tank thus clogging the sock over the fuel pump or fuel filter (should have an external one on the drivers side frame rail).....shot in the dark, but maybe. Any unburnt fuel smells from exhaust?

2xs 12-07-2012 09:00 PM

IMO: Screw it, call the state regulating board that oversees this inspection program, explain it to them, they can make the shop fix it.

punchesdfw 12-07-2012 09:32 PM

Already checked for vacuum leaks with the starter fluid method. Pulled the TPS & MAP Sensor and checked them again. I have good pressure in the fuel rail, so I don't think it's a fuel problem. I think I'm going to cut the Cat off and see what happens. I can always weld it back on.

... It's Driving me freaking CRAZY! I've filed a complaint with Texas DPS on the shop. That's gonna take a couple of weeks. Meanwhile, my Daughter doesn't have her Jeep and she's driving my car.

punchesdfw 12-14-2012 07:18 AM

After all of that I finally found the problem. It was an intermittent Fuel Pump. I installed a new unit with the 20-gal sending unit and it runs better than ever.

2xs 12-14-2012 11:29 PM

Awesome! good to see your up and running again!

Speedy4x4 12-14-2012 11:33 PM

Quote:

Originally Posted by punchesdfw (Post 3102610)
After all of that I finally found the problem. It was an intermittent Fuel Pump. I installed a new unit with the 20-gal sending unit and it runs better than ever.

How much and where?
I like the idea of just doing the swap but I love the idea of new parts? Links?

punchesdfw 12-15-2012 07:11 AM

Quote:

Originally Posted by Speedy4x4 (Post 3105797)
How much and where?
I like the idea of just doing the swap but I love the idea of new parts? Links?

$130 at O'reilly Auto Parts
Spectra Premium SP736H - Fuel Pump & Sender Assembly | O'Reilly Auto Parts


All times are GMT -5. The time now is 11:13 AM.