Hey Guys

[94GTP90SE]

Hey what’s up guys. I’m new to forums for cars; but I’ve been wanting to talk to other W body owners so I can figure out the issues with my cars. I previously owned a 1990 GP SE coupe with a decently rare option set, but I had to sell. I now just purchased a 94 GTP and I’m unfamiliar with the motor and some of its issues. ( Fans won’t kick on/ car won’t restart once heated up/ dies in reverse sometimes when power steering strains/low rpm flutter) I hope you all like the car anyway!

 

[55trucker]

Hi there, what would you like to know about the DOHC engine?

Are those mid 2000's Impala wheels on that car?

[RareGMFan]

2 hours ago, 55trucker said:

Are those mid 2000's Impala wheels on that car?

Pretty sure they're '04 & up GP wheels.

Welcome to the boards, 94GTP90SE. I see you've got the TGP/'91-'93 hood with the bigger vents.

[94 olds vert]

The passenger fan is set to kick on around 230F which. I think is too hot. The driver side fan should kick on around 210F. Check wiring to the fans, any fuses and relays. Possibly it could be time for a new thermostat, new coolant, and maybe new fans if the electricals check out good. 

When I had a 3.4l it ran pretty consistently around 210F which is normal operating temps for these cars. 

[GTP091]

You can put the ECM into diagnostic mode which will trigger the secondary fan to come on. Will be an easy test of the circuit.  I imagine you checked the fuses in the under hood electrical centre? Next would be the relays for both fans. If the secondary fan comes on when you jumper the OBD connector you can swap the relays and see if the primary fan is bad.  Need a test light, voltmeter and basic trouble shooting skills there. 

[94GTP90SE]

On 10/14/2021 at 7:53 PM, RareGMFan said:

Pretty sure they're '04 & up GP wheels.

Welcome to the boards, 94GTP90SE. I see you've got the TGP/'91-'93 hood with the bigger vents.

I am sorry for late reply’s to all of you, I could not access the site for some time. I do not know much about this particular car, but I do know it was originally Canadian, at least the previous owner said that. Right now she’s stranded in a parking lot, I changed the starter and was doing some testing (fucking off) and when I came back home the bastard died without warning, haven’t figured out why yet.

[94GTP90SE]

On 10/15/2021 at 8:41 PM, GTP091 said:

You can put the ECM into diagnostic mode which will trigger the secondary fan to come on. Will be an easy test of the circuit.  I imagine you checked the fuses in the under hood electrical centre? Next would be the relays for both fans. If the secondary fan comes on when you jumper the OBD connector you can swap the relays and see if the primary fan is bad.  Need a test light, voltmeter and basic trouble shooting skills there. 

I got one of the fans on after running it around and getting to temp, the other I heard will only kick on if it’s really hot?

[94GTP90SE]

On 10/14/2021 at 7:53 PM, RareGMFan said:

Pretty sure they're '04 & up GP wheels.

Welcome to the boards, 94GTP90SE. I see you've got the TGP/'91-'93 hood with the bigger vents.

On 10/14/2021 at 5:16 PM, 55trucker said:

Hi there, what would you like to know about the DOHC engine?

Are those mid 2000's Impala wheels on that car?

Sorry for the late reply, I would like to know a lot of stuff about this motor because I am a beginner, but currently my main problem is the fact that the car is no starting. The starter had started clicking, so I changed it out with a refurbished one, and it started up good and ran for about an hour and a Half before dying without warning. The car was slowing down when it happend. Oil light and battery light went on, I don’t think that means anything as the oil looked good, and the battery is new. I don’t have much tools but I was able to check that fuel is making it to the injectors, and the pump is kicking on, the sender works. There is gunk in the radiator and coolant reservoir I never noticed and I wonder if the water pump seized? But it was never overheating unless the thermostat was already bad but supposedly all these parts were put on new. I’ll probably make a thread, sorry for long reply 

[94GTP90SE]

On 10/15/2021 at 5:45 AM, 94 olds vert said:

The passenger fan is set to kick on around 230F which. I think is too hot. The driver side fan should kick on around 210F. Check wiring to the fans, any fuses and relays. Possibly it could be time for a new thermostat, new coolant, and maybe new fans if the electricals check out good. 

When I had a 3.4l it ran pretty consistently around 210F which is normal operating temps for these cars. 

I think the same, the fans do kick on but there’s sludge in my radiator that I never noticed. Guy tells me he used green, I saw green, hopefully it wasn’t dez cool before that 

[GTP091]

You should post a picture of this sludge.  If somebody mixed coolant types without a drain and flush certain types will gel up and then you’ve got big problems.  I do know that green coolant will gel up if mixed with dex cool but if it was drained a no flushed just once before changing that should be fine. I can’t imagine somebody would be that stupid to mix coolant but hey I’ve seen a lot of stupid.  
 

Definitely do a drain ASAP if you haven’t already.  I’d suggest to get  a bottle or two of coolant flush and flush it twice. Don’t use tap water. There’s a process to flush a 3.4 that you can search up on here, same for the refill as you need to bleed the air out of the top.

id suggest you get a set of GM dealer service manuals for your year and make.  The Haynes and clymer books are to generic 

what’s the status of the engine now?  Will it start? Crank no start? Starts then dies? Starts and dies after it warms up?

Edited October 22, 2021 by GTP091

[94GTP90SE]

15 hours ago, GTP091 said:

You should post a picture of this sludge.  If somebody mixed coolant types without a drain and flush certain types will gel up and then you’ve got big problems.  I do know that green coolant will gel up if mixed with dex cool but if it was drained a no flushed just once before changing that should be fine. I can’t imagine somebody would be that stupid to mix coolant but hey I’ve seen a lot of stupid.  
 

Definitely do a drain ASAP if you haven’t already.  I’d suggest to get  a bottle or two of coolant flush and flush it twice. Don’t use tap water. There’s a process to flush a 3.4 that you can search up on here, same for the refill as you need to bleed the air out of the top.

id suggest you get a set of GM dealer service manuals for your year and make.  The Haynes and clymer books are to generic 

what’s the status of the engine now?  Will it start? Crank no start? Starts then dies? Starts and dies after it warms up?

raining hard yesterday night and this morning, wasn’t able to get back out to where it’s stuck. Currently the car just goes wom wom wom wom wom wom. For eternity (starter noises I am immitating) but does not actually start or even sound like it’s gonna. My head is a little spinning because I’m not smart enough to diagnose the issue right of the bat and I don’t know where to begin. I’ve got all the nessaxry equipment and parts to overhaul the cooling system, save for a few thing I will have soon. Nothing is leaking anywhere, fuel is in the rails, could this be a CPS sensor or coil pack? Will post sludge picks toda!

[GTP091]

If it was running and then just died without warning it probably won’t be related to the coolant issue you also have.  These engines are great when they’re in good repair but like anything else they become uncooperative if left to long.  This is likely just an issue of lack of maintenance.  You’ll just need to be systematic and make a plan and write it down. Seems silly to do this but it helps immensely especially after you’ve forgot all you’ve done.

id start by pulling codes.  Use the paper clip trick to get the car into diagnostic mode (do a search on here) The secondary fan should start.  The check engine light should flash 12 three times and then nothing if there’s no codes. 1 flash is 1 - 2 quick flashes is 2.

You need spark, fuel, good compression, and no mechanical damage to the engine itself if you have those in good order it’ll run. If you think it’s a spark issue it’s probably fuel related and vice versa.

Can you test for spark? If the crank sensor gave up, the ignition module won’t get get the pulse and you won’t have spark.  I had this happen and ended up replacing a bunch of parts when I didn’t have to. 30 bucks later and no skin on my knuckles and it fired right up, that was in 2003.  You can test the crank sensor with an analog voltmeter but it’s complicated and not a perfect test, so much easier to test at the plug wires. You’ll need a spark wire tester.

One of these -> lisle 19380 or 26900.  It tests from the plug wires instead of at the connection to the plug or coil.  A regular in line tester isn’t much help as they’ll all be to short to get into the plug well from up top and it’s a bitch to get at the ignition module because it’s under the front exhaust manifold.  I’ve relocated my ignition pack because it was such a pain to get at.

If you have fuel at the rail that’s good but if the pressure is off too far  it won’t start and you won’t know without a proper tester.  You’ll need around 42 psi and it needs to hold. 

I recently had an injector quit completely and even though my car will run if I pull a plug off completely it died completely with one dead injector. Not stuck open or leaking it wouldn’t open at all. I have an injector harness so that helped immensely once I had the plenum off.

start with the easy stuff though, check for loose grounds and connectors, don’t forget to make sure the battery connection is  tight. Did any harness for the various sensors come out? You’ll need a digital voltmeter.

we can all help you on here, it’s what we do for each other to keep our cars on the road without taking them into a mechanic that just scratches his head and says he hasn’t seen one like this, and tells you ‘herb would know but he retired’.  We need more info though on what exactly happened when it quit.  

Was it driving fine and started to sputter and then barely stayed running and finally died and wouldn’t start after?  Or did it just die completely like you turned the ignition off?  How did it run when it seemingly started to overheat.
 

If you can read you can be a weekend mechanic so before you buy car parts get these ASAP. https://www.ebay.com/itm/370699485281?hash=item564f694061:g:orwAAMXQYwFRiNvJ  So cheap it hurts to think what I paid 15 years ago for my set. Also get some beer…

In the mean time I could post pictures from the troubleshoot sections from my manuals but will be touch different as I have map and you have MAF sensors. 

Edited October 24, 2021 by GTP091