Engine Problems!!!

[eweppler]

I have a 92 talon tsi awd that has a rebuilt engine with aout 2,000 miles on it.

Here are the problems i am having. It all started out as a big boost leak and the acceleration had some hesitation and then the radiator was leaking and i didnt notice in time and overheated the car so i replaced the radiator. I got a new intake hose and then the boost leak went away and it worked well for a while. Then a couple of days later the engine started stalling when i came to a complete stop and right away at start up the the rpms would go up to anywhere between 2500 and 3000 rpms and it would stay there for a little while and then the rpms would drop to normal around 750 rpms. Two days ago i was driving to work when i noticed that the boost gauge was stuck at 14 psi for a while and the exhaust was shooting out black smoke at times. Then i got home from work on my break and let the car run for four min before turning it off and then 10 min before i had to leave i started it to let the rpms even out and i went outside to leave and i noticed white smoke rolling from the engine so i ran to the car and shut it off and it sounded like the antifreeze was boiling or else the engine was trying to get more antifreeze. This kinda makes me wonder if it was because i didnt make sure to get out all the air bubles after i replaced the engine coolant sensor. The hole time threw all my problems there has been an engine surge on start up that i thought maybe this was just due to the engine being cold. Also the turbo has been wineing.

I have replaced the radiator, thermostat, radiator cap, intake hose, radiator hoses, fuel pump, and the engine coolant sensor.

Could these problems be the result of having a bad turbo or is there more to my problems? I thought about taking the talon to the mitsubishi dealer just to have them test it and see what the problem is. Is this the way to go?

 

[eweppler]

I have decided that I'm going to have my throttle body rebuilt so I am going to send it to Throttlebodys.Com to have it rebuilt and have the sensors checked as well. A buddy of mine was helping me with my talon and he mentioned that I should just go and get that done. Will be trying to ship it out sometime this week. Hopefully that will fix a problem or tw

 

[eweppler]

I got the throttle body back this week and installed it last night. Fired it up today and there was no more air leak so my seals on the throttle body were shot. Steve at Throttlebodys.Com did a great job on the rebuild. Took it out for a spin today and when I got back to my garage and stopped I let it run for a little bit and it stalled out. I had this problem before and I just adjusted the BISS screw so I'm going to adjust it again and that should work that kink out.

Also my tranny is slipping at times during acceleration. A buddy of mine and I were looking at it a few weeks ago and we figure that my tranny is starting to go so I am currently looking for a used 1G Automatic AWD 6-bolt tranny. The tranny I have in now is a 7 bolt on my 6-bolt engine and it sounds like its hitting a little bit.

 

[eweppler]

After I got the Throttle Body installed the check engine light was still coming on. I decided to go and check all of my connectors and see which ones needed to be replace. I went to the salvage yards and found of the connectors i needed in great shape so I got them and replaced all of them. This ended up clearing most of the codes, now I just have two codes that are coming up; #14 TPS and #31 Detonation (Knock) sensor.

The guy who redid my throttle body should have tested the TPS to make sure that its working right. I must need to adjust the throttle body properly on the car though. Still have some idle surging on cold starts which is probably due to the TPS. I looked over the knock sensor and I notice that it had been rewired in a weird way. So I'm planning on buying a new knock sensor and rewire it back to factory specs.

 

[eweppler]

I have an update on my progress. I went on vfaq.com to see how to properly set my TPS sensor and I went through the steps on there and set the TPS which cleared the code. Then i bought a new 02 sensor and wired it in to the old splices that were made prior to me owning the car and it was still throwing the code. I did some digging into my factory service manual and realized that they made the splice at the wrong connector. It was actually spliced into a connector for the AC which has been taken out. Found the right connector I needed to splice to and what do you know it cleared the code.

The car was still acting up so I decided to do a leak test and found a leak where the throttle body and the intake manifold meet up. The threads on the manifold ended up being stripped out so I went to Carquest and got a Helicore kit and I was able to fix the threads and stop the leak. Started it up the next day and I was still getting the idle surge and the transmission was still hesitating when shifting.

I'm thinking that the transmission is going out. I am also going to do another compression check to make sure that nothing is wrong on that end.

 

[steve]

I've posted many times that the TPS adjustment procedure in the VFAQ is wrong since the production variables in both the TPS total resistance and the actual +5v sensor power make it next to impossible to get the correct TPS output voltage by just setting the TPS to some global resistance value.

The TPS output voltage for a stock ECU should be between 0.48v and 0.52v. This is roughly 10% TPS on MMCd or the TMO dataloggers. Both the ECU and TCU on automatics look at the TPS value and the TCU seems to be more sensitive to absolute TPS values in deciding it's shift points than the ECU is for fuel and spark calculations. The ECU is more interested in changes in TPS values than any specific voltage other than at idle.

 

[moidsm1]

This is a great thread, Lots of good troubleshoooting. It makes me want to go through all my connectors.

 

[eweppler]

Where did they go wrong on the vfaq.com website? What is the correct way to adjust the TPS?

I was looking threw the threads when I was having problems with my talon and I found some things on people with the same problem but they never gave all the details of what they did to fix it completely.

So I decided that I wanted to give people the step by step on what I did to fix the problem so more people with my problem could have more ideas on what to look for.

 

[steve]

Where did they go wrong on the vfaq.com website? What is the correct way to adjust the TPS?

A google search on voltage dividers will start you down the path of understanding what the problem is with the VFAQ.

The correct way on a 1G is to measure the TPS output voltage. That requires the ECU to be connected and powered up and made difficult because it's hard to reach the pins on the TPS while connected. An SAFC or datalogger fixes that since both will tell you the TPS voltage. You set the TPS to output between 0.48v and 0.52v.

 

[eweppler]

Thanks Steve, this information will be very useful to me. I will look at setting the TPS the correct way as soon as I get home Sunday night or Monday night. Just have to get a hold of a datalogger.

 

[eweppler]

I have now set my TPS to the correct voltage, I looked through my factory service manual and it had the procedure right there. After setting the TPS to the proper voltage I took it out for a spin. Still had idle sure upon startup but it was shorter than normal and still had hesitation at my shift points.

 

[steve]

In my experience Idle Surge has nothing to do with the TPS.

It's due to the air bypassing the throttle plate. Too much air and the engine surges as the idle rises and hits the threshold for decel cut off. This can be due to the BISS adjustment, dirty/manfunctioning ISC, misadjusted IPS (1g) or Idle Stop Screw (2G), defective/disconnected FIAV, or various leaks including internal ones like the EGR and PCV

 

[eweppler]

Well I took a look over my engine tonight to make sure everything was tight and there were no leaks. Drove my car a couple of hrs later and it seamed to be worse and the CEL came on. The code that came up was #25 Barometric Pressure Sensor so I'm thinking that my MAS is messed up.

 

[eweppler]

Tested the talon with a working MAS and still the same problem. Then I was out of town for a couple of weeks and when I got back and took the talon for a spin even more CEL codes were being thrown again and was taking a while to get it started up. So I opened the ECU up and noticed that i had a leaky capacitor. Ordered some new caps and replaced them with no change. I'm thinking that my ECU is messed up but I would like to be able to test this out with a known working ECU for a 92 automatic Talon TSI AWD so I currently looking for some one who has one that I could borrow and test off it for a day to make sure its my ECU before I continue.

 

[eweppler]

Today I decided to make a quick trip to the salvage yard to see if I could find a working ECU. I ended up coming across the same exact car as mine, same color and everything. I was unsure if this was a good or bad sign, so I found the ECU laying in the car and another ECU laying in another car along with a few random parts that I needed for the interior for $40. Got home and open the ECU up finding that there was no leaky caps or damage to the ECU whatsoever.

After that I popped it in my Talon and drove it around, no codes where being thrown and the engine was running and sounding a lot better. Keeping my fingers crossed as I continue to drive and test out my Talon.

 

[eweppler]

Update!!

I have been driving my Talon around to make sure that it was running better after I got the ECU. Everything was running better except for the fact that I was loosing coolant but no leaks anywhere. Then I decided to do a compression test and two of the cylinders were past the limit. Took my head off and found that I had a blown head gasket, brought my head to a machine shop and they found that two of my valves were messed up as well and they had to resurface my head.