No body can figure this out..She runs for 10 secs then dies..Its like ar the end where she starts running rough the spark flutters..So far at the local garage ive invested around 600.00 and it still isnt running...Question 1In these year cavaliers are there diodes in the wiring harness that can cause this...2..Has anyone ever had this problem before and if so what was the fix..Thx


1989 Z24
1992 Buick Roadmaster Limited
1993 Buick Roadmaster Limited
1986 Gmc Jimmy 2wd
1983 Chev Camaro
No room for Fords here!!!!lol

Am I reading this correct? You start the car, it runs for 10 secs or so, then dies? Have you checked fuel pressure?

Agreed I would have checked the fuel filter and changed it out.Then do a psi check since I do not know ur engine specs I cannot be more specific.Granted with the money spent I would assume the usual culprits have been ruled out?Please let us know what engine you have is it the 2.8 v6 being it is a Z model I would assume so.IF it is the multiport 2.8 do the psi check if not done already next if that checks ok the injectors would be my next check for ohms for resistance.In short post what has or has not been done so we can better isolate what to consider to recommend could be a number of things like the crank position sensor,bad ecm etc as examples only.

Lets see here there is a brand new fuel pump..tonnes of fuel pressure,new filter,new crank sensor,new spark module & coil pack,Tried another puter from another 2.8 car still does the same thing(Im not ruleing that one out untill I try one meant for a z24)Injectors seem to be fine they were checked and yes its a multiport 2.8 that might have 20.000 km on it from a fresh build...polished ported balanced blueprinted etc.....and a new starter I burnt the old one out trying to figure out the problem


1989 Z24
1992 Buick Roadmaster Limited
1993 Buick Roadmaster Limited
1986 Gmc Jimmy 2wd
1983 Chev Camaro
No room for Fords here!!!!lol

Does it run, then die, and you can start it right up again, or does it take a bit before you can refire it?

If you have to wait a bit, maybe it's getting too much fuel and flooding out? My guess on that would be the ECM, as when a new one is installed (even from another like car) a PROM reset needs to be done.

Well you have replaced what would seem to cause the issue in most cases.Agreed even using a used ecm may or may not work bc the system has to program to run.If you do a new ecm with the new prom/mem cal do these steps 1 turn the ignition switch ON (only) 2 enter the diagnostic mode at the 12 pin hook up or aldl for technical terms.3 allow the code 12 to flash four times this will indicate the prom,calpak, and mem cal are installed properly and the ecm is functioning properly.Now if these codes 41,42,43,51 or 52 pop up or the service engine soon light is constant but is not is not flashing any codes the unit is either not seated properly or defective.Basically this is straight out of the book make sure these are seated and retry and if it pops up again with the old ecm ur prolly need to go to auto zone or advance for a new reman which they do offer.I would bet a reset would fix the issue as ALREADY stated, maybe worst case new prom, memcal, calpak basically a new ecm.Hope this helps and just if you want this came straight out of haynes repair manual 82-94 models 38015 is the manual the two stores above normally have this in stock! I know this section pretty good and did it letter for letter so you would know what to do in case you did not.And this does show the codes all of them and descriptions in detail.Ok

Something to think about..... check the engines oil pressure ! Have had cars with lots of miles, pan was full of crud. Starts up....sucks up all the crud & blocks pickup....pressure drops-engine shuts off, crud drops back off till next startup. You have low miles but... pieces of shop rags (paper type) used during rebuild, metal particles, using sub par oil filter or older one(s) that have started to crumble can plug up the best of systems. If you have the last one from your oil change... cut it open and take a look see. You just might be surprised.

All of the above checks are free.... no parts needed to troubleshoot a "possible" problem.

Hope this helps.

Alan

My dad had this exact problem on his '88 Z24 convertible. You have at least 3 injectors that are shorted out. Injector faults are very common on the 2.8 and 3.1. You must check the injectors when they are cold and the spec I believe is 14-12 ohms. If your injectors are not in this range then replace them.

Well if you do a injector check they should show 11.8 to 12.6 ohms THIS is exact. Josh was sorta close and this is for the 2.8 or 3.1 mpfi engines.Also Something came to mind with the whole picture and that is if the oil pressure sender is faulty it will not ground which can cause the NO run scenario because it is part of the circuit that grounds to make the fuel system complete the circuit!I would ground the oil pressure sender wire and see if it changes the issue,I would pull what should be a two prong sender plug and use a jumper wire.

Thx for the info im going to get right on this


1989 Z24
1992 Buick Roadmaster Limited
1993 Buick Roadmaster Limited
1986 Gmc Jimmy 2wd
1983 Chev Camaro
No room for Fords here!!!!lol

since I cant edit ill add on lol.They were not getting any codes from the computer which was even more baffeling to everyone...Where abouts on the block for starters is the oil pressure sensor??thx


1989 Z24
1992 Buick Roadmaster Limited
1993 Buick Roadmaster Limited
1986 Gmc Jimmy 2wd
1983 Chev Camaro
No room for Fords here!!!!lol

Here again with another question lol ok lets say the oil pressure sensor is done will the car be able to start right back up just to stall again? Same with the injectors..Im oldschool myself I like carbs thats why im asking thx again


1989 Z24
1992 Buick Roadmaster Limited
1993 Buick Roadmaster Limited
1986 Gmc Jimmy 2wd
1983 Chev Camaro
No room for Fords here!!!!lol

Ok based on my book (haynes the overall pic of the eng not a close up.The oil pressure switch (for the oil light on dash) is located on the front of th eng near the valve cover to the left side if ur standing in front of it.Now if the car has a oil pressure sensor(gauge in the cluster) this sensor will be beside the other switch I listed.I would go to http://www.advanceautoparts.com and do a search for parts for UR car with the specs entered into there search so when u look up the part it SHOULD so a pic so u know what to look for.It prolly is screwed in below the valve cover into the block of course.Short is on my 2.0 the oil pressure switch and the oil pressure sensor are side by side in the back of my block but,its a 4 cylder.If u bypass the two with a jumper they should ground,depending on the cars cluster set up with a oil press gauge or dummy light and if it runs then rule out injectors,but I would with a multimeter check the ohms for each injector 1st with just the key ON, and see if they read in the tolerances I listed.That is what comes to mind,I'm stilling thinking on it tho.

On the V6 engine with gauges one oil pressure sensor is on the back side of the block. The other is located right above the oil filter adapter. Remember the ohm spec is 11.8-12.6 if its 11.7 its junk. I have learned from mine that these cars are really sensitive about changes in their electronics.

Check for a potatoe in the exhaust. Seriously. I rebuilt the head on a motor once and it would do the same damn thing. I finally got a talented mechanic down to look at it and he asked is there anything blocking the exhaust?? Oh yeah - I had left a rag in there. I asked him how he knew. He said as a kid that it was their fun game to jam a potatoe up the exhaust pipe of the someone's car and watch them freak out when it would start and run about 10 seconds!! You may have just been ((((potatoed))))

same with the air intake - look for blockage+++++++