so today when i was leaving for work, i started my car (90 NA) and it immediately died and it felt like it just didn't get any fuel. Well after a couple more times trying to start it, the car finally was able to hold an "idle" but not very well. the wideband i have (innovate LC1) was reading really lean, i think it was around 17 at idle. this came as a shock to me because last night it was running just fine with no problems, about 12afr at idle and just cruising was around 14.5. i immediately thought it was the fuel pump which i suspected was giving me other problems such as my inability to redline with out leaning out. i went ahead and pulled the codes real quick just a couple minutes ago and it came up 12 and 18 which are TPS faults on both narrow and wide range. now i have a couple questions that maybe someone might be able to help me with. Question one is, is it common for this to happen just out of the blue? like i said, it was running just fine last night. Question two is, where is the cheapest place to buy one and get it quick, i need to get my car running asap

 

Yes its possible, but it could also be a clogged or a defective primary injetors. If you want cheap TPS, head down to a local Junk yard or hit up the forsale sections.

 

i guess i could try checking the injectors out this weekend since i won't be doing anything now. i didn't think a clogged injector would cause a CEL for the TPS to go off though. im still waiting on some responses in the FS section, hopefully it wont take too long

 

you know what..you could just need a small tune up.. when i was na, i had this problem alot.. it was always flooded.. somtimes just one spark plug will be flooded and it would cause it to die then maybe start up again.. but just look at the spark plugs and make sure they are not bad too.. that is just a thought.. and also.. my tps was badd too.. my tps went out over night too just like you..lol..

 

so i pulled the TPS of because i was expecting to replace it after a quick visit to the junkyard so i thought i might as well check the resistance as per the FSM and both sensors checked out fine, no dead spots and ohms were right in the middle of factory specs. now im confused as hell. if the TPS wasn't bad then why was it popping up the code for the TPS. could it be that it was just not adjusted properly and a clogged injector/fuel filter could be causing the lean idle?

 

check your wiring connections. if its the same engine wiring harness that was on the engine 18 years ago.... well....

 

One of my primaries went out on me one morning while tuning in idle. Scared the **** out of me. Yes these random things can happen.

Injector was one of the "venom" fraud injectors. Bastards!

 

heres the latest, i put the TPS back in and adjusted it as close to where it should be. I tried cranking it again and it wouldn't even fire once. so i pulled a leading plug and sure enough it was flooding. so i tried the EGI trick and it still sounded like it was flooding. i am getting spark and fuel is obviously there. now i just need to unflood it as best as i can tomorow when its warmer and im not quite as tired. i had to give up because most of my tools are at a friends house. i think i might have a couple spare injectors, but they are from an S4. would those possibly work?

 

well i finally unflooded the engine and got it back to exactly where it was when the problem first came up and took a video. maybe someone can help diagnose the problem after hearing the engine. ill post up the link as soon as its done uploading, its taking a long time for some reason

http://www.youtube.com/watch?v=w5CWjdWquJ0

 

been their before, i know that tone oh too well...........your running on one rotor in that video if its just cuz your flooded pull out all 4 plugs and do the deflood technique, drop in a table spoon of oil in the leading plug hole crank it over once or twice then put the plugs back in, if you have acccess to a blow torch or even gas stove heat your plugs out, they could be just completely soaked

seeing as you have the WB in there and its showing lean, my moneys on an injector problem

 

I'd start by making sure you completely deflood it as noted above. Be sure to pull the EGI fuse, pull both plugs and turn it over in several rounds. I've found the easiest way to inject oil in is to use one of the little flexible spout oil cans. I used 2-stroke oil since it burns completely.

While you've got all the plugs out, you should go ahead and check the compression. I love a signature I've seen on here relating checking compression to getting checked for STDs. It's so true. Here's a video tutorial I made. Be sure to read the whole thread as there are some great extensions to the testing procedure suggested by some of the forum experts. There is no sense spending $350 on a new TPS if the engine is blown.

Be super **** when putting the plug wires back on. It is sooooo easy to get them wrong. And then you're chasing the wrong problem.

I'm curious what you mean by "i put the TPS back in and adjusted it as close to where it should be." I'd make sure it is perfect. The TPS fracks everything else up, even things you couldnt imagine.

Since you can't really get the engine up to fully hot operating temperature, it will be hard to accurately set the TPS. I'm going a bit outside my expertise but I know the biggest reason the car has to be completely hot is the cold start thermovalve which needs to be at least 77 degrees to extend and in turn retract the throttle. Hopefully an expert can validate this idea but in looking at how the system works I dont see any other heat-related factor would impact the setting of the TPS.

You'll find the description of the system on page F1-34 of chapter 4 of the FSM. Since today SA will be in the 60s and tomorrow in the low-70s, it will be too cold to set the TPS. What I would do is get a blow dryer and use it to heat up the water thermo valve (seen on F1-35) and watch the wax rod extend as noted on page F1-36. You might want to disconnect the hoses so that the water doesnt keep cooling it back off. Then have a friend backprobe the narrow range pin in the ECU. Note that you have to count HOLES, not wires, because as I learned the hard way not all of the holes have wires and you'll probe the wrong one.

You only adjust for idle on the narrow range so with your digital multi meter set the narrow range: (2F - Narrow Range TPS)
Then check the full throttle voltage; not set, just check...
Then you validate the full range. Again, you dont set it, you can only check it.

2G - Full Range TPS -
This gives you a lot more information about the status of your TPS than the LED check and I believe is the method favored by HAILERS.

After you do this you need to clear the ECU codes as I believe it stores the last ones for diagnostic purposes.

Be sure to record the voltage numbers you get as the forum experts seem to find them useful.

Good luck,

Jim

 

the video was taken AFTER i had already deflooded the engine. the car acctually got up to operating temp so i was starting to lean towards an injector problem. i don't have access to a compression gauge though, i really wish i had one to use.

what i meant about adjusting the TPS back to where it was, was that i couldn't keep the car running so i tried to visually adjust it back to where it was. then once i got it unflooded and able to idle up to temp, i used a check light to get it closer. i need to find my multimeter though, i was borrowing a friends but he needed it for work.

 

There is an injector test procedure outlined in the FSM. No DMM required!

 

ill look into that tonight after all the family stuff is done, i might end up getting my MX6 running sooner than expected so that would give me plenty of time to check out the whole engine on the 7 and maybe even fix the problem i was having with the engine not reving over 6500 at WOT and possibly play around with some porting and rebuilding. but ill go ahead and check out the fuel injectors first before i get into any of that. i appreciate your help VR. do you ever make any trips down to SA?

 

Ironically, no. We've lived in Austin 2.5 years and the only time I've been to SA was when my flight from DC was diverted to SA because they only put enough fuel in the plane to get us here and there was a shower over Bergstrom.

Good luck on the car. When I was thrashing on mine this summer I was preparing to do the FSM injector test. Even bought the wire!

Good luck on the project! Oh, and you have 3 Harbor Freights in SA so go get a compression checker and DMM. They are cheap and Harbor Freight love you long time!

 

ok, heres the latest:

i found a TPS from a member on the forum and just got that put in. the good news is that the engine started easier than before this time but it still sounds the same and doesn't want to stay running. im starting to lean towards the rear rotor having low compression and possibly some carbon build up on the seals. based on what you have heard in the video, what do you guys think? also i tried some AFT in the rear rotor but im not sure exactly how much i got in there or if any went in at all because i couldn't find anything around here that would work easily. after a few attempts i pulled the plugs out and found a bit of what looked like carbon deposits on the tip of the plug. should i try getting something to put some of that Marvel Mystery Oil and then try cranking it to see if it will unstick the possibly stuck seals? I really don't have to time to be pulling out the motor so im trying to do little things here and there.

 

pulled codes again and this time 10 and 8 popped up, the air flow meter. i think my car hates me

 

i told you before, its runnin on 1 rotor since its running on the lean side the injctor is not firing or else it would be showin super rich on your WB o2...which is a pretty common thing to have the primaries crap out on you you goin to have to pull the UIM to get to the primary fuel rail

Unless there is something tripping your fuel cut to the rear rotor but most likely the injector


unplug the injectors and turn your ignition power on and test to make sure they're getting the 12v constant at the plug goin to the injectors to make sure the ignition drivers in the ecu are good, you can apply 12v to the injectors while they're still in there and listen for them to click, if its just a frozen injector it could be enough to knock it free, but if the rear sound weaker or doesnt click it'll def need to get cleaned,you would be best off to pull the injectors out and send them to get cleaned then you know you wont have a problem with them for a while down the road

 

i pulled the UIM off about 10 miniutes ago and tested both injectors and neither were clogged, the only injector i found that was clogged/stuck was the front secondary which would explain why that rotor seems to not be clogged up. the whole thing with my car was that when i got it i couldn't redline it because of what seemed like an electrical problem so i could never get rid of the carbon build up by reving the motor all the way up. well if that front rotor was never getting enough fuel i would think that it would be less likely to have carbon build up like the other rotor. im still 90% sure that its that MAF/TPS that is causing a bad signal to the ECU which is cutting the fuel. ill probably clean them while they are out anyways and get that other one fixed. hopefully i can get something figured out soon because im tired of not being able to drive it.

 

got everything put back together with the newer TPS and a borrowed MAF that was good. the car is still having the same problems but is not throwing any codes at all. im fresh out of ideas now. the only thing that would be keeping it running lean would be the primaries would it not?