Tps

Is it possible to have a bad TPS and not throw an SES light?

1995 Cutlass Ciera 3.1 auto

It is possible but uncommon for a bad TPS not to trigger a DTC code and SES/CEL light. You can check the reference voltage from the ECM module and then the output of the TPS as you vary the accelerator from closed to WOT.

What problem are you having? Is your Cutlass odb-i or odb-ii?

It is possible but uncommon for a bad TPS not to trigger a DTC code and SES/CEL light. You can check the reference voltage from the ECM module and then the output of the TPS as you vary the accelerator from closed to WOT.

What problem are you having? Is your Cutlass odb-i or odb-ii?
How can you tell the difference between OBD-I and OBD-II? I've got the shop manual and read where you could check for codes possibly without a scanner, but stated some 94-95 models needed to be checked by a scanner.

It's been surging/fluctuating and dying when I press the gas to accelerate after it's at normal opertating temperature. It doesn't happen all the time, but happened this past Friday. Ultimately the car died. So I cranked it back up and sat for a couple of minutes, got back on the freeway and it did okay.

95 was a bad year because it was a transition year from odb-i to ii. There should be a data label located around the radiator area or support which may annotate what it has. Also, you can check to see if you have a 12 pin data link port. 12 pin is odb-i and odb-ii has a 16 pin, however, some odb-i models had the 16 pin port.

Here is a tech link which may help, especially if it is odb-i.

Click here (http://www.troublecodes.net/GM/)

95 was a bad year because it was a transition year from odb-i to ii. There should be a data label located around the radiator area or support which may annotate what it has. Also, you can check to see if you have a 12 pin data link port. 12 pin is odb-i and odb-ii has a 16 pin, however, some odb-i models had the 16 pin port.

Here is a tech link which may help, especially if it is odb-i.

Click here (http://www.troublecodes.net/GM/)
If it is in fact the 12 pin, will I be able to get a trouble code even though the SES light is not on?

Do you have any ideas what the problem might be with the symptoms I've stated?

The car died on me again on the way home yesterday. I was even at cruising speed maybe 50 mph, not at WOT and it just died on me. I had to crank on it a couple of times and it finally started back up, but died again a couple more times before I finally made it home. Any ideas? I'd really like to get this resolved this weekend. I don't want to have to take it to someone.

The car died on me again on the way home yesterday. I was even at cruising speed maybe 50 mph, not at WOT and it just died on me. I had to crank on it a couple of times and it finally started back up, but died again a couple more times before I finally made it home. Any ideas? I'd really like to get this resolved this weekend. I don't want to have to take it to someone.

Have you check for proper fuel pressure at the fuel injector rail and how old is the fuel filter?

Although you may not be getting any DTCs possibilities are the crank position sensor. There are two. A 24X and 3X. Also, a cam position sensor. Any one of these components could cause a stall out or hard starting.

It is either fuel or ignition related.

Have you check for proper fuel pressure at the fuel injector rail and how old is the fuel filter?

Although you may not be getting any DTCs possibilities are the crank position sensor. There are two. A 24X and 3X. Also, a cam position sensor. Any one of these components could cause a stall out or hard starting.

It is either fuel or ignition related.

Well the car had about $1200 in parts put on about 3 months ago, including, fuel pump, fuel filter, fuel sensor, r&r injectors, replaced no.6 injector. Unless the car had some faulty parts put in, it leads me to believe it's going to be an electrical component. That's why I had my original question, because I figured something electrical would cause the SES light to come on. I'm gonna try and get some kind of code tonight by trying the trouble code check.


My next question is how do you decipher the codes. How does a SES light, pause, SES light, SES light= Code 12?

A code 12 is "technically" no distributor/spark reference pulse. But since you're doing a key on/engine off test, that code should always come up first. Each code will flash 3 times, in numeric order. When it cycles back to 12, you're done retrieving codes. If a 12 is all you have, then there are no trouble codes stored. If you don't have a code list, post them here and we'll help you decipher them.

He's got all the possible DTCs Rich and how to decipher the SES/CEL light . See my post #4. His problem is not getting any SES/CEL light, therefore high probability of no diagnostic trouble codes.

http://www.troublecodes.net/GM/94-95_31M.shtml

Thanks a lot guys for your help. I will definitely post up the codes, if any, here when I get them. If I don't have any codes, then I wonder what the next step would be. Also after I start it...it does smell a little rich for a few seconds and then goes away. I forgot to mention that earlier.

Okay guys, here's the latest. I was gonna do the code test last night, but as stated in your link, some 94-95 models don't have terminal B. Well of course my car doesn't have terminal B. So I went to Pep Boys and asked him if they scanned it without a service engine light, would they find anything. He of course said no, but you can pay $84 for a full diagnosis and we'll tell you what's wrong. I told him what it was doing and he said it could be the Fuel Pressure Regulator. That sounds logical to me, but is there an easy way to test the pressure at the regulator?

It is possible but may be confirmed by checking fuel pressure at the fuel injector rail.

Okay last question. Can I check the fuel pressure without using a fuel pressure guage?

To test it effectively and see if it is in GM specs I doubt it. It is important to see the minimum pressure the fuel pump is putting out. There should be a Schrader valve on the rear fuel injector rail passenger side of engine where you can connect the gauge. They are not expensive. Around $25 at places like Autozone.

http://i5.photobucket.com/albums/y186/lizzywiz/alerofp.jpg
Checking fuel pressure GM 3100/3400

To test it effectively and see if it is in GM specs I doubt it. It is important to see the minimum pressure the fuel pump is putting out. There should be a Schrader valve on the rear fuel injector rail passenger side of engine where you can connect the gauge. They are not expensive. Around $25 at places like Autozone.

http://i5.photobucket.com/albums/y186/lizzywiz/alerofp.jpg
Checking fuel pressure GM 3100/3400

Cool. Thanks man, I guess I'll go and get one from autozone this evening.

Cool. Thanks man, I guess I'll go and get one from autozone this evening.

It may come in handy for the future and can be used on other cars too. Just another tool to add to the tool box. The one shown is the Actron brand which has a bleeder valve built in. So it can be used to relieve fuel pressure like for replacing a fuel filter. I got this one at AZ. Good luck.

It may come in handy for the future and can be used on other cars too. Just another tool to add to the tool box. The one shown is the Actron brand which has a bleeder valve built in. So it can be used to relieve fuel pressure like for replacing a fuel filter. I got this one at AZ. Good luck.

My only concern now is, since the car only acts up after running for a little bit, won't the fuel pressure be inaccurate since I'm checking it cold?

My only concern now is, since the car only acts up after running for a little bit, won't the fuel pressure be inaccurate since I'm checking it cold?

The fuel pressure will be fairly constant whether the engine is cold or hot. It changes depending on engine vacuum conditions. Initial readings are taken with engine to off, ignition to run (fuel pump prime) and then checked with engine running. The fuel pressure regulator (FPR) is vacuum operated. So the vacuum line to the FPR is removed and reconnected to see if there is a pressure difference. A difference around 4 - 6 psi would indicate a possible flaky FPR. Checking fuel pressure is just one step in the troubleshooting process. Until checked it is hard to rule it out. If fuel checks out then other areas would have to be looked at such as ignition. Components that are heat sensitive and can cause intermittent problems would be the two crank position sensors (24X and 3X), the camshaft position sensor and the ICM.

The fuel pressure will be fairly constant whether the engine is cold or hot. It changes depending on engine vacuum conditions. Initial readings are taken with engine to off, ignition to run (fuel pump prime) and then checked with engine running. The fuel pressure regulator (FPR) is vacuum operated. So the vacuum line to the FPR is removed and reconnected to see if there is a pressure difference. A difference around 4 - 6 psi would indicate a possible flaky FPR. Checking fuel pressure is just one step in the troubleshooting process. Until checked it is hard to rule it out. If fuel checks out then other areas would have to be looked at such as ignition. Components that are heat sensitive and can cause intermittent problems would be the two crank position sensors (24X and 3X), the camshaft position sensor and the ICM.
Man...thanks a lot for your help. I'm gonna check the fuel pressure tonight and I'll let you know. Also if either of those sensors are bad, wouldn't it show an SES light?...and what do you think about the coolant temp sensor being bad?

Well I've been procrastinating the past couple of days and haven't checked the FP yet. I have concluded that the problem only occurs with about 8 gallons or less of fuel.

I thought I'd let you guys know. It ended up that the fuel tank walls are rusting and that's what was causing my problem all along. The guys that did all the repairs originally in June, went ahead and put a new fuel tank assy. in and noticed the contaminated fuel. I found a new tank for the car, so me and my brother in law are gonna tackle this job next weekend.

If you guys know of any tips or shortcuts, let me know and thanks for all your help.