New to me old to the world, TS - pile of problems, can we solve them?

[Blue Bowtie]

Did you happen to test the wires when you had the plugs removed? I've had several Buick 231 engines which ran for LOTS of miles, and all of them eventually had plug wire failures. Several also had coil pack failures.

[Virgis007]

Originally Posted by Blue Bowtie

Did you happen to test the sires when you had the plugs removed? I've had several Buick 231 engine which ran for LOTS of miles, and all of them eventually had pug wire failures. Several also had coil pack failures.

Only did the visual inspection on the ends and as seen through from one end to another, but this of course is not enough. I'll check that when I will be able to.

[Jeffrv]

Wow, I m impressed it only took you 20 minutes to change the plugs, last time I did mine took over 2 hours and left a good quantity of skin and blood behind.
The 2 plugs that seemed to fouled, I don't suppose they were connected to the same coil pack? That would be too easy.
Have you addressed the trouble codes I am concerned you have codes 42 and 43, often they indicate an issue with ignition module or wiring to it. There is a critical ground on mounting bolts underneath the ignition module,( 15MM bolts holding mounting bracket to engine) there should be 2 or 3 wires there, providing ground at least for the module and the PCM
Jeff

[Virgis007]

Hi Guys!!

I'm back, with my questions and problems.

Hope you all guys are okay with this damn virus floating around...

So I got this new problem...

I've been doing removal of the old LPG system from the TS, and I had to cut out wire (let's call) reconnections, because the LPG system had i'ts own control module for the lpg system, so quite a lot of non needed wires were there. There were wires interupting/reconnecting to the fuel injectors, to the lambda and one little wire I could not locate yet were was it going out from. So the ones I found, that were cut and resoldered I connected and soldered back to the original locations. Did about 10 resoldering back to original, and I found the wires going from the fuel pump and I found the + wire, to get the feeding for the LPG system as I am redoing the LPG into a simple version. I cut the plus wire, and divide it through a simple three pole switch (one gives + to the fuel pump (as originaly should be), one (middle) is nothing (no fuel no LPG) and the last one gives the + feed to the LPG open-close electro valve). So I got the LPG system converted into the simple version, for the tests to guess what is up with the engine. After resoldering wires back to the original I wanted to start the engine and check if it works at all after all this stuff (looked kinda complicated, I was woried if I did any mistakes not to fry something or short circuit) but It started real good, and the engine work became much smoother and more powerful! Straight after this I wanted to take it for a quick spin. Drove it out of the garage and then stepped on it to the bottom, damn it was a real beast! But just for the moment, really weird. As the engine heated up a little bit, all the power went away and the engine started working as it was before. And it was like this - while cold goes smooth and good, as it heats up it gets worse and worse with the performance. Last time I parked my TS, before shutting off the engine the sound changed a bit, I could not understand.
This morning started it up, and drove it to the garage (about 3-4 kilometers) and when cold this time it was already not well performing. So at the garage I decided to check the ignition coils, to remove them and to check the resistance with a multimeter. And guess what, after I remove them one after another, then I put them back, and tryed to start it up... And nothing! Not a single pop was out. So now I am afraid, that while removing and installing back the ignition coils I might have fryed (somehow) the ignition module (the one under the coils)... While removing the coils I didn't unconnect the battery (my bad, this might be also the reason ). What do you guys think? What else might be? I didn't do the paperclip test, maybe that would point to the main problem?

[Blue Bowtie]

It should not be necessary to disconnect the battery before removing ignition coils. Simply turning off the ignition should be sufficient.

The coil packs are mounted onto the ICM, and are bolted through it. The ground connection for the coils and ICM are the mounting bracket. I have seen several of those mounting brackets with ennough corrosion to prevent a good ground. Cleaning and polishing the surface with a moderate abrasive is usually enough to establish a good ground.

Verify that the spade connectors from the ICM to the coil packs have not been accidentaly bent from removing/installing the coils, and that they are clean. It would also be good to verify the other connections to the ICM, including those to the crank position sensor(s) and cam sensor.

[Virgis007]

Originally Posted by Blue Bowtie

It should not be necessary to disconnect the battery before removing ignition coils. Simply turning off the ignition should be sufficient.

The coil packs are mounted onto the ICM, and are bolted through it. The ground connection for the coils and ICM are the mounting bracket. I have seen several of those mounting brackets with ennough corrosion to prevent a good ground. Cleaning and polishing the surface with a moderate abrasive is usually enough to establish a good ground.

Verify that the spade connectors from the ICM to the coil packs have not been accidentaly bent from removing/installing the coils, and that they are clean. It would also be good to verify the other connections to the ICM, including those to the crank position sensor(s) and cam sensor.

Thanks a lot Blue Bowtie! I definitely remember that I noticed the bad corrosion on the bolts and brackets, I even had a thought oh my, thats badly corroded! This will be the issue, because I thought it is not important, because I thought that only the two connections to the coil packs are just plus and minus, and the ground goes through minus but it seems then it is not. Will try to clean, and hopefully it works again! Thanks again.
I think that because I will again do things with the coil packs, i guess it would be also really good to remove the stuff deeper and to check the good grounding mounts.

[Jeffrv]

While you are checking the corrosion on the brackets, make sure the ground wires connected to the bracket are clean and not broken. The PCM ground is there, possible IC as well; if these are faulty the engine will not start.
Do the paper clip test again to see if codes 42 and or 43 reappear; if so you may have issues with the IC. GM manual states it is virtually impossible to test the IC in the field, and basically to replace it only after exhausting all other checks.
Were you operating the engine on gasoline or LP? Does it have any way of warming the regulator or vapourizer? I seem to recall our propane forklifts at work had engine coolant routed to the underhood units. Is it possible your LP system froze up after a few minutes of operation, restricting the fuel to the engine?

[Virgis007]

Hi again guys!

Got some good news also some bad ones.

I have cheked and did a lot of those stuff you guys recommended above for me to do, so now I've got my TS back on the road, but with still not properly working engine, with check engine light on.
What I did:
Cleaned the mounting brackets of the ICM, cleaned the coil brackets, checked the ground wires (cleaned), then assmbled everything back, checked everything with the multimeter beeping from coils, and the bracket with a random engine metalic place (generator base, and some other metal bracket on the engine) to see if there is a good ground. After this the TS fired up from the first crank, but was working really poor. Then I checked the coil resistances, two had same resistances, and one had a real big resistance, so decided to change this one. Bought a new one (blue color, but doesn't matter if it works ) installed, engine seems better now, but not good still. It now runs drives, but no power, and you can hear the engine idling quite rough, and when you drive it, if you go carefull with the gas pedal, then it is possible to ride, but when you step on it - it back fires like hell. It even seem like the back firing is real hard, big noise of course and the engine kinda-like stopping for a second during the back fire.

Both fuels run the engine the same, but when engine is at it's working temp it is almost impossible to drive on LPG because it shoot's badly, the engine even stalls (looks like to the air filter side, the air filter should be squashed now because of the shooting). Petrol seems better, possible to drive, but only smoothly stepping on the pedal, because the harder stepping the worse it works (backfires/shoots).

Paper clip test now shows only (12) 42 and 43 codes.

Thinking of checking/cleaning the wiring connections to the ICM again and other modules, because during cleaning of the bracket of ICM I found the connection to ICM had oxidation. But witch exactly wiring connections should I check (were to find them)? And what else? Maybe to change the coil-to-spark plug wires? Would that help..? Running out of ideas.. 43 is Knock sensor, could this do something with the shooting/backfiring?

Thanks again for the tips guys, we are slowly but getting to the goal - removing the check engine light from the dash and feeling the true power of the GM 3.8 monster !

[Blue Bowtie]

It may be that the knock sensor error (43) and EST error (42) are related.

Verify that the spark plug wires are correctly connected. The firing order is as follows:




If you have not already done so, check the connetors for the crankshaft position sensor (CKP) and camshaft position sensor (CMP). Also be sure the tan/black wire on terminal "B" has a good connection and that there is +5V present on that wire when the ignition is on:




The spark plug wires can be tested for continuity with a multimeter. 1000-5000Ω per meter of length is typical.

It might help the diagnosis if the knock sensor is bypassed temporarily. The knock sensor connector can be disconnected and the circuit can be connected through a 3,900Ω (3.9K) resistor to ground to force the ECM to accept the signal level and not set the 43 error code.

[Jeffrv]

As Blue Bowtie suggests, check for wiring issues on the wire on terminal B. Also check for issues on the adjacent wire, Terminal C. Both these wires go from IC module, across top of engine, and are in the wiring bundle that goes from front of engine to the 30 pin bulkhead connector mounted next to strut tower. This wiring harness has over the years caused me no end of grief with wires breaking internally, so when you check for continuity, don't be shy in flexing the wiring bundle to check it. The manual also states to make sure the spark plug wires are not routed close to the wiring bundle, as stray voltages could be induced.
When the engine initially starts starts, it is the ICM that controls spark, not the PCM. GM says this allows the engine to start in one sixth the time versus letting the PCM figure out where the engine is in the timing cycle and starting it. At 400 RPM the engine is considered started, a signal is sent back and forth on these 2 circuits, and control of spark is transferred to PCM. An open or short in either of these 2 circuits will prevent that from happening, a code 43 will be set, and the ignition remains in a fixed mode at 10 BTC. In this mode the manual goes on to say that if you could get the injectors to work in some fashion, in theory, the engine will run without the PCM even being connected, but with very noticeable performance issues.
Thoroughly check the wiring bundle, it has caused me a lot of issues in the past. Also all wiring associated with cam and crank sensors, spark plugs etc. If that checks out, then in all likelihood, your ICM needs to be changed

[Virgis007]

Hi guys,

Didn't have found time to check on the tips you guys advised. Will do as soon as possible.

Quick question.

I found localy parting out a Buick LaCrosse 2007 3.8 petrol automatic
The engine form the pictures seems identical to my TS.
Maybe the ignition module, the coils and the wires would fit? The main question of course is the very ignition module it self, would it fit? Maybe there are some other cars, that have the same module used? Because I am very hard in finding the parts localy, or the prices are real big. I have a feeling that the ICM is faulty in mine. I checked the wire boundles (the connections) all looks good, clean, no oxidation, i sprayed it with electro wires cleaner, and put all those connectors back. Bad thing I didn't have a multimeter by the side then, would have checked other stuff.
So I think for a fair price I should get a spare ignition module, and try changing it when possible. (It's a quick change no big deal, harder to find it self).

[ctesla]

Virgis,
i didn't know they had Pontiac TranSports in Lithuania..
but seriously, your 93 w/3.8 is VERY common; and so it is possible to swap from MANY other General Motors vehicles...
BUT- i believe your 1993 had two options for the ignition control module (ignitor)..
their was a 14-pin unit, and a 20-pin unit..
whichever yours has, it will interchange with almost all 3.8 GM units;
from 91-08 buicks: park ave., century, lacrosse, lucerne, regal, riveria, etc..
..chevy impala, lumina, monte carlo- 95-04...
.. 95-99 Oldsmobile 88 royale, 98 regency, achieva, cutlass ciera (and cruisers w/3.3), silouettes, and toronados from the early 90s...
.. and 92 to 07 Pontiacs; bonnevilles, grand ams, grand prix, and including your TranSport...
more than 350 different types of GMs used this module.. good luck finding it..
the 20-pin GM/AC-Delco unit should have a stamping on it: 1103936.
hope this helps

[Virgis007]

Originally Posted by ctesla

Virgis,
i didn't know they had Pontiac TranSports in Lithuania..
but seriously, your 93 w/3.8 is VERY common; and so it is possible to swap from MANY other General Motors vehicles...
BUT- i believe your 1993 had two options for the ignition control module (ignitor)..
their was a 14-pin unit, and a 20-pin unit..
whichever yours has, it will interchange with almost all 3.8 GM units;
from 91-08 buicks: park ave., century, lacrosse, lucerne, regal, riveria, etc..
..chevy impala, lumina, monte carlo- 95-04...
.. 95-99 Oldsmobile 88 royale, 98 regency, achieva, cutlass ciera (and cruisers w/3.3), silouettes, and toronados from the early 90s...
.. and 92 to 07 Pontiacs; bonnevilles, grand ams, grand prix, and including your TranSport...
more than 350 different types of GMs used this module.. good luck finding it..
the 20-pin GM/AC-Delco unit should have a stamping on it: 1103936.
hope this helps

That's great news you shared ctesla, thanks a lot!

The thing is that, yes we had Pontiac TranSports but most popular were with 2.3 engines. But as known the 2.3 engines were not reliable, so it was common to swap the engine with 2.0 85kw Opel engines, as these were realy reliable and quite an easy swap to do. So after the swap you had a really economical and with a big space inside comfortable and good looking for the time car/minivan. In Lithuania they were real popular at around 2000s. When I was looking for a Trans Sport my self I tryed to find the one - with a swapped 2.0 opel engine, but I could not find any (found one but really bad condition). But there we had another problem. Around 2012 the local laws were changed - it became more strict about swapping engines for cars, and somehow (didn't go deep into this) it was hard for 2.3 to Opel 2.0 swapped TranSports to pass the technical inspection. This Law change killed lots of TranSports in Lithuania, usually they were running on the streets until their technical inspection (in the UK it's called MOT i think? In the USA i dunno ) was valid, and after they were just dissassembled and sold for parts or just scrapped.
So mostly only the not swapped 2.3 remained today and the more rare in Lithuania 3.8, also I saw a 3.1 in a junkyard that's been sold for parts, but engine and trans was out long ago, and only the body with rear chassis was left and doors. Also saw a Lumina Chevy, quite good shape for it's age, but someone grabbed it before me
For the day today, it is hard to find parts for TranSport, all the locals I called they only have some remaining parts from older times, and I haven't seen another TranSport or Lumina or Silhouete on the road running... They kinda fade away, and turn into history...! ;(

[Virgis007]

Hi guys! Got some good news!


So I kinda got annoyed that I can't find any parts for my Pontiac Trans Sport 3.8 holy cow..!!
Calling all the parts scrap yards, local car part dealers, all the shops related with car parts, even one that only goes for american car parts as they state..... And to them the Pontiac Trans Sport 1993 is a really old car and they have nothing left, can't find where to order.......

So one evening after work with my little daughter playing around me I just put posts on almost all car related groups on Facebook, and the market place that I am looking for any parts remaining and any Pontiac owners that have or had Trans Sports 3.8 who can sell me parts or atleast give me info about them. And this was a great success, I should have done this earlier...

I found two guys who previously had TS 3.8'ths, and they shared some good and valuable info with me, and also found a guy who has his old TS 3.8 still parked, standing for about 2 years in his big warehouse and said that he would just give it away for a guy who would still do something with it like saving or at least for own parts, for only some 200 euros or something, because he's not really using it, but it's just too sad to scrap it..
I found to buy the ICM, and two spare original coils. Checked them by the resistanse they look good. Just as received, changed the ICM. And yup, the code 42 is now gone!

I did all of those checks Blue Bowtie and Jeffrv told me to do. All seems like no bad stuff in wiring. So I only needed to get a spare ICM.

And so guys, after changing the ICM and the code 42 is gone, the 43 is still remaining.

Thanks for those guys they told me the page to order Pontiac TS parts. I ordered the Knock sensor and some pipe flange gaskets because my exhaust is bad and loud, the gaskets where the manifolds connect are probably dead. And the page is rockauto.com it's a USA page, but the guys said the parts come in only about one week so I can wait for them to come.

About engine work. It is not still satisfying, and sorry guys!! I haven't yet changed the spark plug wires...... I just could not find them for Pontiac...! But I have them ordered now, as soon as I receive them, will change straight away...

And can you guys now share info on where it is located on the engine the Knock sensor, where it's connection is from the sensor via wire to where it connects and so on. Will check for corrosion and other stuff at first, maybe it is possible to measure the resistance of the sensor, or some other stuff? As one guy told me the KS has only one wire going to it, so it is probably working via resistance changes, or how...? Need info on that, and this is the last code, the finish line is now seen..!!

[Virgis007]

Update on last thread.

I found info on our forum member LMP's database (hope he's not mad for taking those from him..! )

http://www.avigex.ca/xport/sensors.jpg
http://www.avigex.ca/xport/dtc43.jpg

So pretty much enought info about the Knock sensor, so now only waiting for the sensor and spark plug wires. Meanwhile I'll check sensors wire (for visual breaks or smth) and what voltage I have there.