So aside from small issues here and there, my Series 3 3800 swap has been running pretty well up until last weekend. Cruising down the street when all of the sudden it lurches, the gauges sort of trip up, but then it picks backs up and drives. Another half mile or so down the road, and all of the sudden it dies. I try clutching in and turning it back over but all it would do is crank, so I pull it into a parking lot. I try and diagnose the problem a bit, look for a loose ground, etc, but it's kind of hard to get under there without a jack so I call a tow truck. As I am waiting a guy comes over and pushes the pintle on the fuel rail Schrader valve and I jump in....starts right up. I leave it running, get home, park it on the road so I can move a car out of my driveway. Go to start it again, no luck. I try the pintle on the fuel rail again, no luck but fuel comes spraying out. I end up having to push it into my garage.
Fast forward to today - I go in, crank a few times, it starts and idles for a few seconds and then dies as the idle comes down to ~1000 RPM. Crank again - same thing. Crank again - same thing. Then, it stops firing again and I am back to the same problem as before. I check and there is pressure at the rail, the oil pressure gauge is moving, and the RPM tach is jumping.
Now - I did drop the fuel tank about 3 weeks ago to fix my fuel gauge, the float was stuck. Put everything back up in and it was running fine for at least a few trips to work and back, no issues at all.
I am a bit lost here. Any help is appreciated. Thanks!
Maybe the injectors arent firing? Try a squirt o starting fluid in the throttle body, if it fires right up, Id say injector issues. Tachs moving so you have spark. Post up the fix when you find it. Good luck!
There's two things that can help here: spark tester and injector noid lights. Noid test lights you disconnect a wire to an injector and plug the wire into the test light. Determine if either the injectors or coils aren't firing.
I've never worked on a series 3 but the many 3800s I've handled you can have a tach reading but have no spark. I've upgraded the 3800s in my cars(Buick Reatta) to the later ignition module and coils your engine has. Tach reading comes from crank sensor and passes through the ignition module, it isn't dependent on the coils actually firing or even the ICM working properly. Another quirk is that the ECM can't detect a failing ignition control module directly. These modules are very prone to heat failure, this is even worse in the Fiero engine bay. When my ignition control module was failing it would only act up after I was driving and the heat built up in the engine bay. After that the car would have trouble starting resembling a failing fuel pump. A crankshaft position sensor can also be failing but only show symptoms part of the time. Sometimes the vanes on the harmonic balancer can become just slightly bent and lightly brush against the sensor slowly wearing the plastic cover off.
I'd say test your ignition control module and crankshaft position sensor. Crank sensor can be tested with a multimeter by reading one of the signal lines(there's two) and cranking the engine. Look up the pinouts and use wire probes(the kind you poke through the plastic insulation on the wires). Ignition module some parts stores like autozone can test. If you verify you have both pulse signals from the crank sensor but no spark then the module may be the culprit.
Thanks for the help so far guys. I may try those injector noid lights. My other question is then, why the random starts? Just an intermittently working part that is starting to fail? And why did it seem like it would work until it idle down to ~1000RPM and then die each time? Is that a point at which it switches sensor or something to run, and may not be getting a signal? Again - thanks for all the help!
Thanks for the help so far guys. I may try those injector noid lights. My other question is then, why the random starts? Just an intermittently working part that is starting to fail? And why did it seem like it would work until it idle down to ~1000RPM and then die each time? Is that a point at which it switches sensor or something to run, and may not be getting a signal? Again - thanks for all the help!
Something to consider as well is failing ignition coils. I assume your series 3 is supercharged? You absolutely need healthy coils here. Luckily these engines use three separate coils so maybe try swapping a known good one in one at a time. You can measure resistance of the coils to determine if one is failing.
As for the random starts, the ignition module is VERY prone to heat damage. The variant of ICM your engine has helped mitigate this a lot but the issue is still there. It could run fine all day when it's 220 degrees but once it's 230 it'll decide to poop out until the temp drops. These things are such a pain I built my own tester for them.
One thing I can think of is the 3800 engines run in batch fire fuel injection mode until they reach closed loop. Batch fire does not require the camshaft position sensor. When the temperature reaches a set point the ECM switches to sequential fuel injection which uses the camshaft signal plus crank signal. On my 3800s closed loop(and thus sequential fire) is when it drops the rpm down from 1100-1200 to 750(proper idle). If you start the engine after it's been sitting overnight does it run fine until the temperature rises to around 160-170?
Have you checked the ECM for codes? Only part of the codes for these engines will actually trigger the check engine light.
Easiest way is to connect at the OBDII port and scan for codes. Otherwise you are working in the blind.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Bergman - yep, L32. I thought maybe coils but it's strange that I don't really get misfires so much as just nothing. With a coil going bad I would think the other two would work and fire. Dennis - Sometimes it feels like I am always working in the blind
Honestly I've been doing a lot of brainstorming and researching but have only tinkered with the car a little bit to check fuel presure, plug wires, etc. It's one of those things where I just haven't had the motivation to tackle this problem just yet for two reasons: 1. I have tackled quite a few since it started running and it's gotten a bit frustrating and 2. I have been gone quite a lot and hate tearing into something just to come back and go "now where was I...?"
Anyway - first thing I'll do today when I get home is scan for codes and see what comes up. If nothing, I may undo the ICM and take it to Advance or somewhere to get it tested (having your own tester must be nice!).
I'm leaning toward something electrical having failed/failing...just not sure what that is. If it's the cam sensor or ICM, I won't be terribly upset except for the fact that ICM's seem to cost an arm and a leg for OEM. If it's a crank sensor I am going to be fairly upset, WHY DID THEY HAVE TO PUT IT BEHIND the crank?! There are plenty of crank sensors that can read from the side of the block or ANYWHERE else that wouldn't have been such a pain lol. I'll report back with what I find!
I went out, try to start it, same thing as usual. Gave one breath of life but nothing after. Crank crank crank. Scanned the vehicle. No codes at all. Good news (I think?). So I jack it up in preparation of inspecting it tomorrow, thinking I will check wiring underneath, down the sides, sensors, grounds etc. I wiggle the connectors by the battery tray as well as at the ICM, and figure what the heck, I'll try to crank it over again. Crank crank crank boom. Starts up. Now...I have been leaning toward electrical and I don't want to rule that out just yet...but is it possible that my pump could have fallen out of the holder? I did drop the tank a couple weeks ago. But if so...woud it not pump correctly or maybe not be able to get fuel? I find that strange but at the same time, bad ICM doesn't seem to jive with jiggling wires or jacking it up. Maybe the pump fell to a point where now it is getting enough fuel to fire? To counter this point though...if there is fuel in the rail you would at least think during my many attempts at cranking it would have at least sputtered. Oh the joys! As always, I appreciate any input! Your guess is as good as....no wait...probably better than mine.
I went out, try to start it, same thing as usual. Gave one breath of life but nothing after. Crank crank crank. Scanned the vehicle. No codes at all. Good news (I think?). So I jack it up in preparation of inspecting it tomorrow, thinking I will check wiring underneath, down the sides, sensors, grounds etc. I wiggle the connectors by the battery tray as well as at the ICM, and figure what the heck, I'll try to crank it over again. Crank crank crank boom. Starts up. Now...I have been leaning toward electrical and I don't want to rule that out just yet...but is it possible that my pump could have fallen out of the holder? I did drop the tank a couple weeks ago. But if so...woud it not pump correctly or maybe not be able to get fuel? I find that strange but at the same time, bad ICM doesn't seem to jive with jiggling wires or jacking it up. Maybe the pump fell to a point where now it is getting enough fuel to fire? To counter this point though...if there is fuel in the rail you would at least think during my many attempts at cranking it would have at least sputtered. Oh the joys! As always, I appreciate any input! Your guess is as good as....no wait...probably better than mine.
There should be a ground cable mounted to the block below the bracket the ignition module bolts to, likely on one of the bolts holding this bracket to the engine. Ensure the ground cable and bolt here are clean and tight as the ignition module grounds through this bracket.
Pump: It's possible, not much holds these pumps in their bracket, but the hose that connects the pump to the fuel line wouldn't allow it much movement. A fuel pressure gauge would help. Just wondering, any idea how much gas is in the tank? I made the mistake of trusting the fuel gauge before.
Give it a bit then try starting the car without it jacked up and without fiddling with the wires.
Yep, so that is one of the wires I wiggled, as I remembered putting that ground to that cast iron bracket, but it is so hard to see without removing the bracket to check it's condition. May pull the belt off and remove the bracket so I can give it a good look.
Good to know on the pump not being able to go far. I've been thinking about renting a FP tester too. I've probably got ~5 gallons or so in the tank. I had just filled it before this all started happening so I know there is some gas in there.
I'll see if I can recreate the problem again today. Lord knows I am going to try every possible wiring avenue before dropping that dang fuel tank again.
So today the car started up again, but I decided before taking it out for a spin I should at least check the ground for the ICM, make sure maybe it isn't loose. I take the tensioners off the coil pack bracket so I can get to the ground, it seems good, solid connection so I piece everything together again and it fires up again. I let it idle 5-7 minutes without issue. Feeling like taking it for a spin, I go to the grocery store no problem. Come out, it fires up and then dies. I check the Schrader valve and there is fuel at the rail. "wiggle some wires" at the ICM, get back in, it fires up. Pull out of my spot and up to a stop sign, it dies. Key off and back on, it fires up and I make it home without issue (only maybe 1.5 miles or so).
Maybe it could be the MAF? This thing just dies so suddenly it is strange. That is why I have kept thinking ICM. But I do this "wire wiggling" and it seems to come back to life. Maybe there is a loose wire in the connector to the ICM? But why the heck die in the grocery store parking lot after just sitting there?? Man this is frustrating. I am too nervous to drive anywhere now.
I have never looked at a series 3 pcm, but I know the series 2 pcm will run with the MAF disconnected (unless you have some really bad tune). I wouldn't go doing any big pulls like this or anything. But if it runs fine with the MAF disconnected, and then wont run when you reconnect it, that can either point to or rule out your MAF sensor.
Did you check "all the inputs" to the ICM connector including the inputs from the connectors at the ECM. You may want to wiggle the appropriate wires on that end as well. A continuity test of each of those input wires wouldn't hurt either. I'm not sure if your series 3 has a sub-harness connector like the Series 2 but this sub-harness connector starts near the "firewall side" fuel rail and splits off to feed the ICM, CRANK SENSOR & CAM SENSOR.. Think of it as a mid-point for troubleshooting the ignition system.
A friend of mine had issue with his 3800 not re-starting within 10 minutes of shutting down. Waited 20 minutes and all is fine, starts right up. Had it to Dealer several times and found no reason for the problem. Finally someone at the dealer got smart and used a water hose and sprayed cold water in the area of the crank sensor and it fired right up. Turns out the crank sensor was sensitive to heat and would fail until it cooled down. You may want to get out the garden hose.....
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
That's been my issues for years now and finally figured it out last month. Mine would get wet through the cone filter I was using then dry out and work. I thought it was a wiring issue and rewired half my car.
------------------ Project Genisis Lo Budget 3800SC swap 12.840@104.8 MPH Intense-Racing 1.9 rockers, 3" exhaust, 3.4 pulley, ZZP tune and 18 year old tires.
This same thing happened to mine, After replacing crank sensor, cam sensor...still wouldn’t stay running...turned out to be my MASS Airflow sensor.
Apparently the oil I used to treat the Air filter, shorted it out.
K & N filters are famous for dirtying up MAF sensors but it usually doesn't kill them. You can clean them with special MAF cleaner.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I've driven it ~25 miles since it last had an issue with no problems. Granted this is not a lot of miles, but enough for the engine to warm up each time and give it some pulls. Ran like a top each time (knock on wood). Going to keep poking around, pull my MAF and see if it is real dirty. I'm wondering if the temps dropping has had something to do with it. The other times the problem occurred, it was pretty warm out if I recall correctly. Anyway....all just guesses for now until (or if....please be if) the problem comes back and I have a chance to do some troubleshooting. Thanks everyone for your help and ideas so far though. Definitely some stuff I wouldn't have thought to check like the MAF.
