ycartf Posted February 24, 2007 Report Share Posted February 24, 2007 I know this is a post of something I already had on here but I figured with a more appropriate title it may elicit specific help so please forgive me. Ok so I finally got off (work 24 hour shifts at two different jobs) and got me a fuel pressure gauge. The specs for the fuel pressure are 40-47psi at the Schrader valve and my gauge registered 48psi while the fuel pump primed, and 40psi once it pressurized and stopped running - I did this twice because the first time I did not see what the pressure was while priming - got the same results both times - so it looks like it is not the fuel pump. I cannot do it today as I am working again today, but I was told by a coworker that the fuel injectors might be malfunctioning. He said I should take out a spark plug (after trying to start it for a few seconds) and see if it had fuel on it. Also, there were still no trouble codes logged when I checked. I plan on towing this to the house Saturday morning when I get off and testing all 6 plug wires for spark (rolling the engine for the back 3), then checking for gasoline on the plug(s). Should I check all 6? And again, this was running fine when shut off and would not start 10 minutes later. Recap: Engine turning over fine Spark to at least the two plug wires I checked Fuel pressure 48psi (while priming) and 40psi (once primed) at Schrader valve No trouble codes logged Still will not crank (Just over 113,000 miles on this and lots of life left in my book) Thanks for any and all help. ycartf@yahoo.com Quote Link to comment Share on other sites More sharing options...
Crazy K Posted February 24, 2007 Report Share Posted February 24, 2007 I's say alot of miles. my lumina drivetrain sits at 222k and lived to go into another car. check at least one spark plug wire from each coil for spark. go ahead and check all 6 cylinders for fuel. I know on one car I had a non-start issue because two injectors jambed open. cylinder 2 and 4 were full... which I then cranked the engine with the plugs removed resulting in a nice fireball... OOPS! have you tried starting the car with starter fluid? Quote Link to comment Share on other sites More sharing options...
ycartf Posted February 24, 2007 Author Report Share Posted February 24, 2007 I have not tried with starter fluid but along that train of thought I did try: -taking the air intake boot off -holding the butterfly assembly open on the air intake -spraying WD40 in while trying to crank This did not work (recommended by my brother who used WD40 some time ago). Two other firemen I work with told me that WD40 "used to be" flammable enough to use for starting but is not anymore. I now need to get some starter fluid and try it. We had an almost-all-day fund-raising event for our daughters' youth group and I am just getting in. I will post the results of the starter fluid trial. Thanks again. Quote Link to comment Share on other sites More sharing options...
ycartf Posted February 25, 2007 Author Report Share Posted February 25, 2007 I tried it (the above) with starter fluid and it would start briefly each time I sprayed a bit into the intake - but seemed to get nothing else fuel-wise and would stop the moment the spray was exhausted. I was a bit timid about spraying any more than very small bursts as the first time gave me a short backfire with flash coming out of the air intake (accumulated WD40 that was ignited I reckon). I am guessing fuel injector problem but I fail to see how all six would go out/clog at the same time (assuming there are 6). What might regulate the function of them? Thanks for all help. Tracy Quote Link to comment Share on other sites More sharing options...
ycartf Posted February 26, 2007 Author Report Share Posted February 26, 2007 I know this is a post of something I already had on here but I figured with a more appropriate title it may elicit specific help so please forgive me. Ok so I finally got off (work 24 hour shifts at two different jobs) and got me a fuel pressure gauge. The specs for the fuel pressure are 40-47psi at the Schrader valve and my gauge registered 48psi while the fuel pump primed, and 40psi once it pressurized and stopped running - I did this twice because the first time I did not see what the pressure was while priming - got the same results both times - so it looks like it is not the fuel pump. I cannot do it today as I am working again today, but I was told by a coworker that the fuel injectors might be malfunctioning. He said I should take out a spark plug (after trying to start it for a few seconds) and see if it had fuel on it. Also, there were still no trouble codes logged when I checked. I plan on towing this to the house Saturday morning when I get off and testing all 6 plug wires for spark (rolling the engine for the back 3), then checking for gasoline on the plug(s). Should I check all 6? And again, this was running fine when shut off and would not start 10 minutes later. Recap: Engine turning over fine Spark to at least the two plug wires I checked Fuel pressure 48psi (while priming) and 40psi (once primed) at Schrader valve No trouble codes logged Still will not crank (Just over 113,000 miles on this and lots of life left in my book) Thanks for any and all help. ycartf@yahoo.com Also I have now gotten it to run for a second or two at the time with starter fluid sprayed into the air intake with the butterfly held open - any ideas on fuel injectors being the problem or why/how? Thanks to any who can offer any advice. Quote Link to comment Share on other sites More sharing options...
Crazy K Posted February 27, 2007 Report Share Posted February 27, 2007 sounds like... shorted out injector unless it is a bad ecm/pcm. I suggest removing the plenum and using a digital mulitmeter to check the ohms of each injector. On two occasions I was very lucky and discovered the failed injectors were the only two your could unplug without removing the plenum (# 1 & 6) in both those cases I tried to start the engines with the accessible injectors unplugged and it ran fine except for the obvious misfire. then I did the nitty gritty with an ohmeter once the plenum was off. and and it's not that all six clog or anything... the internals of the injector burn out or something... basically creating a permanent ground which shorts out the entire injector circuit. I wish I had good ohmeter readings of the first two total failure injectors I removed. But I will have bad ones to meter soon... from my 93 3.1 vert. Fresh *used* injectors.... next week! p.s. used injectors seem to be about $50 for a set from typical j/ys. Quote Link to comment Share on other sites More sharing options...
greekguy7 Posted March 1, 2007 Report Share Posted March 1, 2007 Injectors should read slightly over 12ohms. If less than that, replace. When my car was runnig like crap, I found 3 that were 11.1, 9.4 and 9.5.... keep in mind thats at room temp and the reading may be much worse when they get warm Quote Link to comment Share on other sites More sharing options...
servoalt Posted March 4, 2007 Report Share Posted March 4, 2007 as i understand it... the injectors are wired in a way where one will go out and take the rest out due to resistance... ? this happened to my 2.8 cavalier once. It was running fine, then it died. i thought it was a fuel pump, so i had my "guy" take it in. he said when one injector fails, the rest will also puke. sorry i dont have better details but this was long ago and i didnt even understand at the time. anyway, he threw in some used injectors he had laying around the shop, and had it goin in no time. sounds like you need a new set. just a thought Quote Link to comment Share on other sites More sharing options...
Crazy K Posted March 5, 2007 Report Share Posted March 5, 2007 as i understand it... the injectors are wired in a way where one will go out and take the rest out due to resistance... ? this happened to my 2.8 cavalier once. It was running fine, then it died. i thought it was a fuel pump, so i had my "guy" take it in. he said when one injector fails, the rest will also puke. sorry i dont have better details but this was long ago and i didnt even understand at the time. anyway, he threw in some used injectors he had laying around the shop, and had it goin in no time. sounds like you need a new set. just a thought correct. they are on the same circuit, one shorted disables them all. Quote Link to comment Share on other sites More sharing options...
servoalt Posted March 5, 2007 Report Share Posted March 5, 2007 Hey, I just found my spare fuel rails and all my injectors, and the injector harness. I'll check the injectors for resistance and see if they're good. Some are from a 89 6000 2.8 and some were from my 89 cavalier 2.8. They do need to be cleaned... Does anyone know if these would work for him? I'll send them out for cost of shipping, and I get a discount on DHL because I work at OfficeMax Here's how the resistance checks out @ 78 degrees: 11.1 11.3 11.6 13.0 13.2 12.3 4.1 (OUCH, this might be the bad one!) 8.9 (ouch again) Quote Link to comment Share on other sites More sharing options...
ycartf Posted March 6, 2007 Author Report Share Posted March 6, 2007 I think my ECM will be the easiest to check first and if it is ok then I am going to proceed to the fuel injectors. I have another 91 3.1 Lumina (only difference is that it is a 4 speed AT and this one is 3) so I can use parts back and forth (or at least am going to try and use the computer ECM off the old one). So if I have to have injectors or the ECM I think I am going to go ahead and make this second one a parts car for the first. BTW - does anyone know an easy way to disconnect the ECM from the wiring? It appears to have four sets of small "locks" you have to depress to get it to turn loose and I have to wait until my brother can come by so I will have two sets of strong hands. Thanks so much and as soon as I can get this diagnosed I will post it. Quote Link to comment Share on other sites More sharing options...
RJansen658 Posted March 7, 2007 Report Share Posted March 7, 2007 as i understand it... the injectors are wired in a way where one will go out and take the rest out due to resistance... ? this happened to my 2.8 cavalier once. It was running fine, then it died. i thought it was a fuel pump, so i had my "guy" take it in. he said when one injector fails, the rest will also puke. sorry i dont have better details but this was long ago and i didnt even understand at the time. anyway, he threw in some used injectors he had laying around the shop, and had it goin in no time. sounds like you need a new set. just a thought correct. they are on the same circuit, one shorted disables them all. All 6 Injectors share the same positive feed line, they are activated by a ground pulse from the ECM. If one of those ground feeds burns up, either from the injector internally or from the wiring to the injector, it results in all being in-op from the constant ground. Usually it blows a fuse when this is the case. I do not believe (correct me if I'm wrong), that the ECM requires any cam or crank reference to pulse on the 3.1L MPFI's. Autozone rents "NOID" lights which will instantly tell you if you are getting injector pulse. You just unplug the injector, plug the wire onto the noid light, have someone crank the engine, and see if the noid light flashes. I think my ECM will be the easiest to check first and if it is ok then I am going to proceed to the fuel injectors. I have another 91 3.1 Lumina (only difference is that it is a 4 speed AT and this one is 3) so I can use parts back and forth (or at least am going to try and use the computer ECM off the old one). So if I have to have injectors or the ECM I think I am going to go ahead and make this second one a parts car for the first. BTW - does anyone know an easy way to disconnect the ECM from the wiring? It appears to have four sets of small "locks" you have to depress to get it to turn loose and I have to wait until my brother can come by so I will have two sets of strong hands. Thanks so much and as soon as I can get this diagnosed I will post it. The ECM will easily swap between the two. To unlock the clips just press them in and pull the connectors out of the ECM, should require minimal effort. Once you have both ECM's you are gonna wanna switch the MEMCAL module. Each ECM will have a little anodized aluminum cover on the side held on by 4 screws, with a rubber gasket to seal it. Under the cover is a memory module, a lot like a PC memory stick, with retaining clips very similar to a PC. Just switch the modules and you will be good to go. I suggest grounding yourself out before reaching into the ECM as static electricity may damage it. Quote Link to comment Share on other sites More sharing options...
ycartf Posted March 9, 2007 Author Report Share Posted March 9, 2007 Ok here is the latest (still not starting). I swapped the computers so it would be one that was running fine a few months ago when I parked the other car. It still did not start. I checked the spark (again) to all three front plugs (and thus all three coilpacks) and it was fine. I rechecked all fuses - fine. I took the plenum loose and pulled it back (without unhooking all the intake/throttle stuff) out of the way enough to get to the fuel injectors. I then thought I should make sure that the injectors were getting juice so I took an analog multimeter and set it to 10 volts (the lowest setting) and put one prong in each of the two slots of a fuel injector electrical terminal. When the key was turned to "on" (where the fuel pump primes up and all) I got a reading of like 3 volts. When I turned the starter the reading went down maybe half of a volt. I figured there would be an increased / pulsed current when I tried to start. Needless to say it still did not start. Am I checkng the electricity coming to the injector correctly or is there a better way to check it? Does that reading sound normal if it was the correct way? I am appreciative of any and all help anyone can offer and thank everyone who has contributed so far. Tracy Quote Link to comment Share on other sites More sharing options...
Crazy K Posted March 9, 2007 Report Share Posted March 9, 2007 ummm... try ohming the injectors this time. Im not sure if there is any availble standard for voltage reading at the injectors. Quote Link to comment Share on other sites More sharing options...
servoalt Posted March 9, 2007 Report Share Posted March 9, 2007 take a look at the pictures i posted. then do the same on your car... then use my injectors to get your car running, and leave your "parts car" alone lol i still have all the injectors/harness/rails sitting here waiting. depending where you live, it's be like $5 to ship all. Quote Link to comment Share on other sites More sharing options...
RJansen658 Posted March 9, 2007 Report Share Posted March 9, 2007 Am I checkng the electricity coming to the injector correctly or is there a better way to check it? Does that reading sound normal if it was the correct way? I am appreciative of any and all help anyone can offer and thank everyone who has contributed so far. Tracy There are NOID lights. Rent them at AutoZone for like a $40 deposit. They plug right onto the injector harness connector, and when you crank the engine they will flash if you are getting the correct signal to the injector. Quote Link to comment Share on other sites More sharing options...
ycartf Posted March 9, 2007 Author Report Share Posted March 9, 2007 But before I peel injectors out, is there any way I can check and make sure current is getting to the injectors? Since one injector can short them all out? I unhooked all 6 of them and I was wondering about if I should have checked them one at a time with the other 5 still connected. Thanks a bundle and I may have to take you up on those injectors - thanks! Tracy Quote Link to comment Share on other sites More sharing options...
BXX Posted March 9, 2007 Report Share Posted March 9, 2007 2.8L/3.1L Injectors don't short out, shorts cause nasty blown fuses and the occasionally burned wiring.. You have either 1 clear to 6 bad injectors... The injectors are bank (group) fired. The ECM's injector driver circuit can only handle a certian range of impedance... When one injector's coil goes bad, the circuit of three injectors breached the range the ECM can drive, thus shutting off than bank since the driver circuit overheats.... Not to mention, 2.8L/3.1L can barely run of 5 cylinders 2.8L/3,1L have severe injectors issues, not only are the Multec injectors crap n the first place, but they take in a lot of abuse from the heat due to them hiding up underneth the intake plenum... More of story, 2.8L/3,1L injectors are good for around 100K miles... After than, they already are pretty much clogged and the windings are un-reliable... DON"T USE AN INJECTOR UNLESS IT HAS A RESISTANCE READING OF 12.4-12.8 OHM!!!!!!!!!!! Old/bad injectors are the #1 cause of bad ECMs in 2.8L/3.1L equipped vehicles Quote Link to comment Share on other sites More sharing options...
ycartf Posted March 9, 2007 Author Report Share Posted March 9, 2007 SO............ Are you saying I should not use old injectors from a parts car/junkyard/etc? I saw at AutoZone they are like $60 apiece and I hate to fork out $400 for this if I do not have to. Also, when I check the resistance reading can I do that without taking them out AND do I check them by putting the probes on each of the two spades? Thanks so much - I am not feeling nearly as lost as I did about this. I was told by AutoZone that they no longer even sell (much less rent) the NOID lights and that I can test for injector pulse by using a test light attached to one terminal of the injector harness and a ground and try to start. The same guy also told me to check the ignition module (underneath the 3 coilpacks). I have a few more things to try once I get another chance (not until Sunday after Church). Thanks again to all!!! Tracy Quote Link to comment Share on other sites More sharing options...
servoalt Posted March 10, 2007 Report Share Posted March 10, 2007 You can check impedance with them in the car. Just unplug the harness and use your multimeter on each of the two terminals on the "ohm" setting. Advance Auto sell the noid kit. I saw it yesterday while getting an axle nut socket and a pickle fork. If I remember right, it was $18.88 and comes with attachments for ALL types of injectors, even cars with tbi. That might be your best bet, but I would definitely check the resistance of the injectors first because its sooo easy. Where are you located? Maybe someone here is close enough to lend a hand. Quote Link to comment Share on other sites More sharing options...
ycartf Posted March 10, 2007 Author Report Share Posted March 10, 2007 I am located in Dothan, Alabama (southeast corner of Alabama) and appreciate the offer, but I "think" I can tackle this. About this time last year I did the front struts, a CV axle, both valve cover gaskets, and replaced the timing belt and water pump on my wife's old 1990 V6 Camry. I have done brakes, radiators, starters, alternators, etc. lots of times on other domestic cars and feel pretty confident about that - but this is my first time with this level of tracing an electrical problem down. I just felt overwhelmed with all of the possibilities of things it could have been or still could be I guess, but you guys/gals are sure helping out in that area. The last thing I posted about the ignition module that I was told - does that sound right? I am now thinking that if it is underneath the coilpacks it seems more like it would control sending juice to the spark plugs - but the guy who told me (have not seen him wrong yet - runs small-town parts store) to check it said it is kind of between the ECM sending a signal to the injectors. I am definitely going to check the ohms of the injectors as soon as I next get a chance before putting effort into anything else and greatly appreciate the help. Also, if I am unable to find the noid lights (assuming all the injectors ohm out ok) and I have to use a test light like was described to me, do I need the rest of the injector harness plugged to the injectors to form a circuit? I ask this because the first time I tried to check them with a test light I had them all unhooked from the injectors. Thanks again all! Tracy Quote Link to comment Share on other sites More sharing options...
servoalt Posted March 11, 2007 Report Share Posted March 11, 2007 The ignition module is underneat the coil packs on the front of the block behind the radiator. All the coil packs mount to it and it has *I think* three electrical plugs and four bolts holding it on. I had to change that on my 89 cavalier as well as a crankshaft position sensor. Might as well do the injectors first, but everything is relatively easy to check on these cars. The CKP sensor is on the back of the block above the transmission but below the exhaust manifold, which also causes a no-start or erratic running issue. I wish I could help more on the other stuff, but I don't know much about it. I'm givin' ya all the info I gotsd. Quote Link to comment Share on other sites More sharing options...
ycartf Posted March 26, 2007 Author Report Share Posted March 26, 2007 Well I checked and all the injectors had the correct resistance. I then checked and found there was not a pulse getting sent to the injectors. I took off the ignition control module - took the coilpacks off and took it to NAPA where they tested it - it was bad / could not find #1 when it searched for it. I swapped the ICM for the identical one on the other Lumina I have and everything runs fine now. I may eventually swap this one back and buy a new one for the keeper Lumina if I decide to sell the other one (all else it needs is a battery and alternator). Thanks to everyone who helped me out - it just happened to be the last thing I would have checked and was sort of hard to get to (especially that bottom bolt of the three that hold the ICM on). I am up and running now - thanks again! Tracy Quote Link to comment Share on other sites More sharing options...
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