Resolved 1G No CEL, No Startup HELP!

[VETTE_50_TH]

Went to drive my car couple days ago when i had a no check engine light in the start postition and when i went to start, just cranked and cranked and cranked. The Fuel pump starts up but the wierd thing is no check engine light. I read the manual and it said that if there is no cel, then a fuse could be blown or light dead. But i cant find that fuse and i still think that the car would run with that fuse blown. Also, the car ran fine the previous day that it didnt start. Where should i start and what could be causing this??

Need help immediately. Thanks in advance!

James

 

[deadly_raptor3]

I had the same problem with my 90 gs-t eclipse....i replaced everything I could find from.....cam sensor,coil pack, plugs, power transistor, starter, battery, wires, ground strap.....still have no start....i also checked the ecm for burn holes or anything weird but nothing ......have fire coming out of the wiring harness going to the coil but no fire coming out and everything is brand new......I am currently working on this problem and when I fix it I will post the answer......Also have checked numerous fuses and all checked out okay...

 

[VETTE_50_TH]

My car has started up for months without a slight hitch and now one day my CEL is gone and car doesn't turn over. Makes no sense, I wish there was some warning that came along, but it was out of the blue.

 

[schoffs4]

Check the mpi fuse near the battery

 

[VETTE_50_TH]

What does the MPI fuse do and where is it located?

Well its another day without out my car working,

The mpi fuse is fine, all the fuses are for that matter.

Checked the coil pack and seems to be working, but I still have no spark and check engine light when I start it up.

I defiantly have fuel cause I took the fuel rail off and fuel spilled out. Not fun. but no spark. What could be causing this?

 

[zimfro]

Vette,
Did you actually: pull the sparkplug, ground the electrode to the motor, and have someone else turn the key to verify the no spark situation? If so, how do you know the coil pack is working? I'm new, but I'm trying to understand the problem completely. Do you have any other details to give?

 

[bling5tatus]

Get a logger and pull the code.

 

[remmargorp]

I apologize for the long-long write up. It is meant to help me as well as possibly help others in the future.

When I refer to the anti-freeze like smell below, I mean the smell as if your heater core has a leak and the hot anti-freeze is leaking into your heater box and through your vents (not the same type of smell as if you were to smell it in the jug).

Approximately a year and a half ago I hear some ticking coming from the interior of my car and then the gauge cluster lights up and the car shuts itself off. I smell a very bad smell like anti-freeze inside the car, very strong. I was unable to get the car to start for another hour, when I finally did, it ran as if you reset the computer for a few days.

Ran fine for the next year and a half until the same thing happened again, heard some ticking, engine kicked off, horrible anti-freeze like smell coming from under the dash. Attempt to get it to start for the next hour, each time trying to start it I would hear some ticking from around where the computer was, smell the anti-freeze like smell and it would kick off.

Many failed attempts (just trying to start the car/reset the computer) to get the car running, sometimes it would other times it wouldn't, finally it stopped working.

Car sat for a week before I could tow it to somewhere I could work on it and then I began the troubleshooting process.

Try starting the car, the car would just crank and never start.

First step:
- Turn the key to the ON position, check for the Check Engine Light (CEL) to illuminate for 5 seconds, at the same time check for the stock boost gauge to move to 0 hold and then drop.

The CEL came on for 5 seconds and then went off, as well the boost gauge moved to 0 psi then slowly dropped off. The CEL came back on for a few seconds, then off then on then off. I then started to hear a lot of quick ticking coming from the engine bay, sounded like the fuel relay kicking on as well as the fuel injectors turning on and off very quickly.

I get back into my car and I begin to smell the same anti-freeze like smell from when the car broke down previously (smell was growing stronger every second the key was in the ON position). I turn the ignition off, smell slowly faded away, ticking from the engine bay stopped approximately 15 seconds later.

I tried starting the car again, the car would just crank but never start.

I could not get the CEL/boost gauge sequence to occur again, ever after multiple resets (disconnect battery).

Second step:
- Check for spark by removing the spark plug wire from the spark plugs one at a time (really only need to do cylinders 1 and 2) and connecting a test spark plug to the plug wire. Touching the spark plug to ground while someone starts the car.

There was no spark across all 4 plugs.

At this same time I also checked compression (180 across all 4 cylinders)

Third step:
- Pulled out the Power Transistor Unit/Power Transistor (PTU) to check

Followed the steps in the manual to test the PTU, it appeared to test OK

Fourth step:
- Pulled out the Ignition Coils to check

Checked the primary ignition coil per procedure in the book.

Readings were 0.9 ohms on pins 3 and 1 and 1.0 ohms on pins 3 and 2.

Specifications were to be within 0.7 to 0.86 ohms

Is it possible that being .04 to .14 ohms higher would cause a no spark issue???

Secondary ignition coils read 13.3 KOhms on both sets, spec was from 11KOhms to 15KOhms

Fifth step:
- Pulled the Engine Control Module/Computer (ECM)

When I removed the case I inspected for any visible damage; leaky capacitors, burnt anything. No visible damage

I smelt the board and I found there was a very strong odor coming from the front of the board (front being the side that has the harness connector on it) under the small heat sink/heat shield. It smelt like the above anti-freeze smell.

No visible damage to anything under this heat-sink/shield but it did have a very identifiable smell which was identical to the smell from when the car broke down both times as well as in the garage during testing/troubleshooting.


Can anyone offer advice? Anyone experience a similar smell/situation? Even though there is no visible damage how possible is it an issue with the computer?

Can anyone recommend a computer repair shop/a reliable source to purchase a new computer?

I have seen a few online like ecmtogo, ecmoutlet, and autocomputersupply that claim to repair or exchange ECU's but not sure if they are legitimate.

Thank you

 

[luv2rallye]

You could have saved yourself a lot of time by posting or searching this forum for leaking capacitors or dash antifreeze smell as this has been a very huge problem on these cars from day 1 with hundreds of posts & articles on it. The smell is usually rotten eggs but sometimes is antifreeze. We would have known immediately what to tell you. Many legitimate companies repair ECU's but also tuners Steve and LightningGSX do. PM them.

 

[10's or bust]

Definately,,move the capaictors around and look closely as you move them and you will see the leaky fluid come out of them!!!!

 

[VETTE_50_TH]

Thats todays battle. Pulling that code if there is one. There is no check engine light, and codes are stored in the ecu. So if its not coming on, i hope its still holding a code for the problem. Yes i did ground the elctrode and the coil is fine because i took it out and tested it. So it could be the power transitor or a short somewhere. Hopefully not from my gm maf!!

We will see.

 

[Defiant]

I can't wait for next week's chapter.

 

[remmargorp]

I have plenty of time and continuously learning different things about this car along the way so I don't see it as time wasted.

I'll have to look harder for the leaking capacitors.

Thank you luv2rallye for recommending Steve, I took a look at his website, hopefully he is still servicing the ECU's.

Defiant, it's only a long post as I was trying to get the most descriptive explanation of the situation, also as many keywords as I could as searches prior to posting were not very helpful. Most results returned things like "car no start, replaced CPU, still won't start"... or very general, non-specific issues.

If I'm going to spend money replacing/repairing a part that does not appear to be damaged but seems to be the cause of the issue, I want to ensure that I have not skipped over a step, or are missing something obvious. (I also have no way of testing the computer, would be nice to have a spare running Laser for testing).

Thanks guys!

 

[remmargorp]

I am troubleshooting what appears to be the same issue.
I am pretty sure I have isolated the issue to the ECU.

In my case I was able to smell a burnt anti-freeze like smell. After testing all the spark plugs, testing the power transistor unit and testing the ignition coil (all checked out ok) I finally pulled the ECU.

Once I opened the case I was able to smell the same burnt anti-freeze smell, however I saw no physical damage to the board.

If you check the wire diagrams for these cars you can trace the ignition system back.

When the ignition is ON there is a constant power to the Power Transistor unit. When the PTU is fed signal (from the ECU) it will switch power to the Ignition Coil. The ignition coil will supply high voltage power to the spark plug.

If the PTU is OK and the Ignition Coil is OK then it is either with the computer or the sensors the computer use to engage the PTU.

From what I can tell it looks like the ECU uses the Camshaft Position Sensor (CMP) and the Crank Angle Sensor/Crankshaft Position Sensor (CAS/CPS).

The only way to test if it is the computer is to put a known-working ECU in your car or put yours in a known-working car (or send the ECU out for testing).

Also,

Turn the ignition ON but do not crank the car over.

This is when the CEL light should illuminate for 5 seconds and then turn off. At the same time the stock boost gauge should move to 0 PSI and then drop off.

Tell us if this happens (I know you stated the light does not come on, but does the boost gauge move to 0 psi?).

If this does not happen then it is either a fuse issue (which you have stated it is not) or it is a computer issue, as this sequence is the computer powering on.

 

[VETTE_50_TH]

RemmarGorp,

Neither of them happen. So wouldn't that mean that its a computer issue. Since the computer isn't coming on to power that CEL or to show there is no pressure at that moment?

Just my thought. You are ###### correct. My car is all torn apart though. As in the exhaust manifold off, intake, and upper intercooler pipe. I Don't think that makes a difference but just wondering. I don't have any friends who own this type of car but I could only get a new one.

Just wondering if there is anything i should try out before I go buy ANOTHER ECU for the car. I hate shelling out the money for something that shouldn't die in a year when i could be getting performance stuff instead. Sucks majorly!

James

 

[steve]

If the CEL doesn't turn on for 5 seconds and go off then the ECU isn't powering up. Nothing interesting is going to happen with the engine if the ECU isn't working. On turbo cars the boost gauge will go to zero and sit there until you try and start the car. Again, if that doesn't happen you have ECU issues.

The ECU needs power to work. That comes from two places, the room fuse than also maintains the radio's setting and the MPI fuse on the battery positive terminal. There is a relay the switches the MPI power to the ECU. To turn the ECU on the ignition fuse has to be good so that the ECU can see the switch turn on, that causes the ECU to pull the MPI relay coil low and activate the relay turning on the main power to the ECU.

You can measure the voltages and figure out where this process is failing. Look up the MPI diagram in your Factory Service Manual (or search my posts to find out where to download the 1G electrical section). Look to see if you have 12v at the input to the MPI relay and then check to see if you get 12v from the ignition switch to the ECU when the switch is un the run position. You see 12v at the output of the relay coil until the ignition is on and then if the ECU is good it will pull the coil low closing the relay contacts and putting 12v to the ECU main power pins.

Considering how common ECU failure is due to capacitor leakage, the is one of the first things to check when your car won't start.

Steve

Oh, and if you suspect that the ECU is acting up have it checked before replacing it. New ECUs from the dealer are $1200, used ECU in various usable conditions run between $100 to $400. repairing them when possible <$250.

 

[moco2448]

hi there sorry to jump in but im haven the same problem on my 90 dsm laser turbo bought newer ecu orignally had a 91 ecu in car just got a 90 ecu now car wont run ??? wondering when caps blow do they fry anything else? if so is that the problem were running into and ive been looking on these posts and a bunch of people are havin this problem right now no one is really fixin it one post said somethin about a fuse in the alternator??? couldnt see one myself but they were talkin about a diff year of dsm ....ps sorry for jumping in

 

[JusMX141]

ps sorry for jumping in

I don't think anyone in the conversation will be offended seeing as this thread is almost four years old.

 

[hypergenesis]

Check if you can push start the car it could be your starter/ starter solenoid? The same thing happened to mine randomly and the CEL wasn't on either

 

[Calan]

I don't think anyone in the conversation will be offended seeing as this thread is almost four years old.

Damn it, you beat me to it.

Wonder if James ever got his car started?

http://www.dsmtuners.com/forums/search.php

 

[dikdiamond]

hi there sorry to jump in but im haven the same problem on my 90 dsm laser turbo bought newer ecu orignally had a 91 ecu in car just got a 90 ecu now car wont run ??? wondering when caps blow do they fry anything else? if so is that the problem were running into and ive been looking on these posts and a bunch of people are havin this problem right now no one is really fixin it one post said somethin about a fuse in the alternator??? couldnt see one myself but they were talkin about a diff year of dsm ....ps sorry for jumping in

If your car originally had a '91 ecu that means that two wires in the ecu harness have been switched,and need switched back so that the '90 ecu works properly. I'm looking through the forums but I can't find which ones to change.

Edituh,here it is http://www.dsmtuners.com/forums/articles-electrical-wiring/302812-1991-1994-ecu-swap-into-1990-dsm-ignition-wiring.html

 

[VETTE_50_TH]

Damn it, you beat me to it.

Wonder if James ever got his car started?

http://www.dsmtuners.com/forums/search.php?searchid=9890628

. Yea i did. A long ass time ago. But i then cut it up and parted it. My new car is not starting because its completely torn apart. lulz

It was the ECU btw. I blew up two of them before i got smart and got one from Steve rebuilt.

 

[Calan]

. Yea i did. A long ass time ago

Well that's good, cause it would be some funny a$$ shlt if you came back in here and said you were still trying to figure it out.

 

[VETTE_50_TH]

As soon as i put in a friends ecu, it started right up.

That would have been funny.