Turns over but wont start!!!

[Retro-D]

Originally Posted by dmorlow

To be honest, I am not sure why I didn't replace the ECM earlier. I was just so focused on the fuel pump and convinced that the fuel pump or something related to the fuel pump was the issue, I completely ignored the ECM error.

Maybe some of the other codes will clear when the ECM is changed. You might try cleaning the EGR later if the code remains, otherwise more $$. Good luck & keep us posted.

RD

[dmorlow]

Well, I changed out my ECM and it made things worse. Now my check engine light is on constantly. I can't get it to go off. (I have a Snapon 2500 scanner. I've gone in and cleared the codes and code 80 will not go away.) The car is shifting wierd now. It waits abnormally long to shift to second gear. Then it immediatly shifts to 3rd gear. Then it doesn't ever go into overdrive. I think the ECM I got was faulty right from the get go. My car drove worse with the new ECM compared to the old one. So I've put in the old one. I am now just going to take my car to another shop and tell them to do whatever it takes to make my car drive nice again. I am so sick of this car!!!

[dmorlow]

Ok, I took my car to another tech. They replaced my throttle positioning sensor. I don't understand why my car is running better now. Actually it's running pretty much perfect. When I replaced it, it ran just as bad. I just can't imagine the chances that the first one was bad. Then I replaced it with a brand new one, and that one quincidently was bad and was causing the same exact issue. Then he replaces it and now the car runs perfect. I don't know if the original problem is just dorment right now and it is going to come back in a few days or weeks. Does it make sense that a TP sensor could cause the car to not be able to start all together and cause my car not to have any fuel pressure (the symptom I was having from the start)? When I was replacing it, I was replacing it to fix a completely seperate issue with my car and didn't imagine in a million years it was going to fix the issue with my car not starting.

[Retro-D]

Originally Posted by dmorlow

Ok, I took my car to another tech. They replaced my throttle positioning sensor. I don't understand why my car is running better now. Actually it's running pretty much perfect. When I replaced it, it ran just as bad. I just can't imagine the chances that the first one was bad. Then I replaced it with a brand new one, and that one quincidently was bad and was causing the same exact issue. Then he replaces it and now the car runs perfect. I don't know if the original problem is just dorment right now and it is going to come back in a few days or weeks. Does it make sense that a TP sensor could cause the car to not be able to start all together and cause my car not to have any fuel pressure (the symptom I was having from the start)? When I was replacing it, I was replacing it to fix a completely seperate issue with my car and didn't imagine in a million years it was going to fix the issue with my car not starting.

I hope all your troubles with the car are solved. I guess time will tell if the TPS was really the problem. Did you get another replacement ECM or are you back to the original?

RD

[dmorlow]

I'm actually back to using the original ecm.

[dmorlow]

Ok, new update. The TP sensor didn't fix it. I went out to start my car yesterday and it didn't start. Any more ideas?

[Retro-D]

Originally Posted by dmorlow

Ok, new update. The TP sensor didn't fix it. I went out to start my car yesterday and it didn't start. Any more ideas?

Scan for codes. Swap the ECM again to rule out the old one being intermittent.

RD

[GuMan]

Most replacement ECM's don't come with an EEPROM.
You need to swap the EEPROM's out. Are you
swapping the EEPROM from your original ECM
to the new ECM?

If so, there could be a reliability issue with the
EEPROM. When this type of EEPROM fails, it
usually appears as data degeneration, or not
flashing correctly. Since your ECM is writing into
the EEPROM constantly, that is where your program
defaults and measured ranges are stored, this
could cause big problems. The only way the
EEPROM is checked by the ECM for errors is by
checksum (there is an error code for this) and
this method does not pick up many problems with
the EEPROM.

When you purchase a replacement ECM, you need
to be very specific to which part number you get.
There are typically 2 to 3 revisions of ECM module
per model year, never mind the EEPROM variations.

Unless you've purchased the right ECM and EEPROM
I suspect your EEPROM could be the culprit here.

[dmorlow]

I did swap out the EEPROM when I did the ECM. But you are saying that it is possible that the EEPROM is bad?
Again, here are the codes I pulled from my car...

36 EGR Pintle Position out of range
52 Defective ECM (ECU RAM Chip Error)
70 Intermittent throttle Position
109 Internal ECM Problem (KAM checksum)

[GuMan]

Originally Posted by dmorlow

I did swap out the EEPROM when I did the ECM. But you are saying that it is possible that the EEPROM is bad?
Again, here are the codes I pulled from my car...

36 EGR Pintle Position out of range
52 Defective ECM (ECU RAM Chip Error)
70 Intermittent throttle Position
109 Internal ECM Problem (KAM checksum)

I couldn't tell you if your EEPROM is no good or not. Your
dealership should be able to. There are many more areas
in the ECM memory map that they have access to that
you do not. Also, they can "try" a different EEPROM to see
if it makes a difference before you buy it.

Did you protect yourself from static discharge
when changing the ECM and EEPROM? A spark with as little
as 200V between you and it is enough to cause damage to
many electronics of this type.

Two of your codes seem to make me think there is a voltage
regulator problem, and the other two make me think there is
a memory controller issue in the ECM.

Codes 36 and 70 can both be caused by a flaky 5V regulator
in your ECM. One of my co-horts was the product engineer
for many of these 5V regulators. This causes the signal coming
back to the ECM to move around, even though the sensor is
not moving. The ECM thinks the sensor is being erratic. Since
your TPS has been relaced (I think) recently, I would guess this
is the case. Also, the EGR pintle position is just another
three lead potentiometer feedback from the EGR motor position.
It also uses a +5V regulated voltage across the potentiometer.

If there are power regulation issues in the ECM, all kinds of
odd behaviour can be had from it.

Since you say you had bad luck with the replacement ECM, I
have to ask if you are certain you received the correct replacement
model. If not, the EEPROM may not have worked with it, and the
ECM would not work well with your car. Model year 1995 had 4
ECM models and model year 1996 went from OBDI to OBDII, which
are completely incompatible with one another.

Dealers have the appropriate Tech Tool scanner to completely
check the ECM, and can access built in tests which no aftermarket
scanner can. Since you have gotten to this level, I suggest you
shop around for a reputable dealer (perhaps a well established
Caddy dealer) and provide them with a clear detailed list of all of
the changes in regards to your ECM.

GuMan

[dmorlow]

Well, here's another update on the car. I brought it to another tech a few days ago and he said when the car wouldn't start, the fuel pump wasn't turning on. So he went to Napa and bought another fuel pump, installed it and the car is running perfect now. What are the chances of that? The old fuel pump go bad to where it didn't start on random days (not going out completely), then my new pump having the same exact issue (just random days the car doesn't start). But he replaced the pump again and now it runs perfect. The part that sucks though is the company that sold me the defective fuel pump won't take it back.

[jagchick]

I know at least a few of you guys have had trouble with yours starting. My 98 has slowly deteriorated with a starting problem. When it has been sitting overnight it starts right up. If I'm at the gas station for a few minutes it starts right up. But if I've driven it and then let it sit 2-4 hours it turns, turns, turns, but takes a few tries to start up. I don't touch the gas pedal, never have. I run premium. Took it to a mechanic, he put a new starter in it, problem remains. He said to put new spark plugs and wires in, did that, problem still remains. What were you saying about a fuse? Oh, and mechanic did a pressure test on the fuel system, it's fine. He said the pump has a small leak, but pumps up right away. I hear the fuel pump come on about 30 sec after ignition is turned, it goes off about 5 sec later. Poor college student here with no more dough to throw at the car. Please help.

[Retro-D]

Originally Posted by jagchick

I know at least a few of you guys have had trouble with yours starting. My 98 has slowly deteriorated with a starting problem. When it has been sitting overnight it starts right up. If I'm at the gas station for a few minutes it starts right up. But if I've driven it and then let it sit 2-4 hours it turns, turns, turns, but takes a few tries to start up. I don't touch the gas pedal, never have. I run premium. Took it to a mechanic, he put a new starter in it, problem remains. He said to put new spark plugs and wires in, did that, problem still remains. What were you saying about a fuse? Oh, and mechanic did a pressure test on the fuel system, it's fine. He said the pump has a small leak, but pumps up right away. I hear the fuel pump come on about 30 sec after ignition is turned, it goes off about 5 sec later. Poor college student here with no more dough to throw at the car. Please help.

I often wonder why people allow their starter to be changed by a mechanic when the old starter is still cranking (turning) the engine? Same with the sparkplug wires, if the car has not been misfireing under load what would lead someone to believe this is part of a starting problem? If the fuel system is showing a pressure leak like (the mechanic has told you) you could have an injector leaking causing a 'flooding' condition after the car has sat awhile and leaked all the rail fuel into the intake. This could cause a long cranking senerio like you describe. The fuel pressure regulator might also be faulty.
Maybe ditch this mechanic, sounds like he wants to sell you everything but what you need to fix the car.

RD

[jagchick]

Thanks, RD. I am not going back to this mechanic, although he has already gotten all of my money. I don't know who to go to that can work on my car at a decent price, since my dad refuses and I certainly can't. But at least this forum helps narrow down the possibilities. I never thought about a leaky injector. How hard is that to fix? And would it cause any other problems besides starting? where does the gas go when it has time to sit overnight? It obviously does not flood after it's been sitting that long. Only when it's been sitting 2-4 hours.

[jagchick]

Oh and when I am cranking it over waiting for it to finally start, sometimes it pops through the intake. I wonder how much a mechanic charges to check for leaky fuel injectors. The only thing dad and I can work on is carburetors, if anything.