Idle and low end bog issue

[bassman5000]

Hello I am new to the site and new to DSMs in general. I have a 91 Talon tsi turbo. I got it cheap because someone was moving out of state and he could not ind out the issue it was having. The car will not idle. fires off then sputters and dies. have to pump or hold throttle till it "cleans out?" and revs up. It is all bogged out until you can get it to some rpms. Get rolling in gear.. bogged out on low end, running like crap.. till it gets rpms.. they it will run liek a bat out of hell.. breaking tires loose at top of 2st and second. Just cant idle and had low end bog bad. He thought it was fuel pump or fuel pressure regulator. I looked at the MAF.. and it looked mangled. some say its a free flowing MAF mob? not sure, but when the MAF is unplugged completely.. it idles.. idles high.. but idles.. and obviously runs like shit with it uinpluged. Unplugged it Idles high. and has a fall on your face bog with over half throttle. I haven't been able to figure it out since i don't have parts to swap on to it. but would him doing a MAF mod like that.. make it to where it was getting to much air on the low end or something of the sort? Any help would be appreciated. It cant be anything to bad. I am having my buddy send me a untouched MAF and some other sensors to try out. ### help. Thanks.

 

[ElectroPanda]

Sounds like an engine compression problem. I would do a compression test. They sell tools to check.

 

[420a dsm kid]

Check your idle air control valve my was doin the same I replace the iac and it work better.

 

[JOSHDIZLE]

Check your spark plugs as well as your IAC valve as mentioned above. My car had a bogging issue as well and a new set of plugs and wires fixed it.

How is the MAF mangled? Are the honeycomb wires missing? If the Mac is damaged it could cause it to give incorrect measurements.

Also is your car throwing any codes or just running crappy?

 

[echamp_1]

I would do one thing at a time. If your buddy is sending you a good mass air flow sensor put that on and see if it makes any difference, and if it doesn't at least you eliminated one possible cause to your problem. Plus it's easy to do. The idle air control valve would also be a good start since those are known to go bad on 1G's.

 

[bassman5000]

Sorry for the very long time to reply. Maf is not here yet. There was a shipping issue. I have not hooked it up to see if it gets any codes because i have to drive it to the parts store to do it and this car is not legal right now since i don't have it reliable yet. I heard the 91s don't throw anything? maybe that's not true. I will try to check the Idle air control items here tomorrow. This is getting annoying though. when I plug the MAF in, it revs up for just a second then it dies. like it gets smothered. Starting ti with the Maf plugged in it fires then dies... fires then dies... fires and give it aton of gas or pumps.. and u can keep it bogged out and hardly running till you let off gas then it dies. Thanks for all the ideas. Keep them coming. Ill let everyone kow what happens when i get the other MAF

 

[Lou98GSX]

i would also check your o2 sensor voltage and make sure its changing cause if its stuck lean it will make the car die and bog .

 

[bassman5000]

Ok cool. Im guessing the O2 on the manifold? Not sure if there are any others. I am new to DSMs. I do think it goes lean and dies when the MAF is plugged in. But it also may be running leaner than it should with the MAF not plugged in. Just seemed to get to the half was point on the temp faster than i thought it should. But I also hear turbo cars just hear up faster. So I am not sure. I am trying to learn as much as i can.

 

[steve]

I have not hooked it up to see if it gets any codes because i have to drive it to the parts store to do it and this car is not legal right now since i don't have it reliable yet.

The autoparts store is likely to say, sorry we can only read OBD2 cars.

Reading the codes from a 1G is easy.
ECU Code Checking
http://www.dsmtuners.com/forums/art...out-scantool-cel-testing-1g-turbo-models.html
http://www.dsmtuners.com/forums/articles-tuning-ecu/319844-1g-code-reader-cel-code-reader.html

Here's how to rest the ISC.
http://www.dsmtuners.com/forums/articles-tuning-ecu/386663-dsm-isc-motor-testing-replacement.html
http://www.dsmisc.com/dsmweb-dw/faqs.html

 

[niddydsm]

coolant temp sensor could be bad

 

[horizontalkev]

Did the car sit for a long time without being started/ran? How are the spark plug gaps? Is the gas below a quarter of a tank?

 

[bassman5000]

Sorry for the delay. The car had been a project for the guy i got it from. he took me for a drive in it.. was horrible to get rolling.. but once it was.. you could get it cleared out and would run like mad when you where into it. I have not checked the plugs because he had replaced them before I got the car.

Would coolant temp sensor really make it run like that?

 

[bassman5000]

Well I have been having horrible issues with shipping lately. Things keep getting lost in the mail. I put a MAF in the car,that I got a very good deal on. and it fired up. It was running high idle and sometimes had a small surge that would come up. Idles around 2000 rpms. Got a multi meter and pulled the codes.. It only was throwing me 31. Knock sensor. I took a reading from the harness and it was read 6 instead of 8-11 or 8-10 what ever it was supposed to be. I am going to order a new sensor today, but everywhere I look online. I cant find the same symptoms for knock sensor issue really. High idle. lack of power with a bog or misfire sometimes. Will knock sensor cause all of this? or is there something that is not coming up on the CEL codes. Please assist if anyone looks at this thread any more.

 

[gsxeclipse97]

Another one of those obvious things.. Make sure the maf is plugged in.

 

[bassman5000]

The maf IS plugged in of corse. How else was I going to test it? I have tested it with maf plugged in. with maf unplugged. Different MAF. New fuel pump. Boostleak test that was "good enough". Read the CEL. eeh.....