Help, I am at my wits end! 1987 olds delta 88

oldsmobile

#1

1987 olds delta 88, 106,000 miles Pulling out onto the road one day, my car died and would not restart. Was idling fine, happened when I hit the gas. Here are the things checked. Ignition control module and coils checked ok at autozone. I replaced the cam and crank sensors, the coolant temp sensor, the plugs and the tps. Most of the time it will not try to fire, it backfires sometimes. I has started twice, but then would not restart. I have spark and fuel pressure, but will not even fire with starter fluid.


#2

Check the compression.

Was the engine noisy at all before it died? As in, maybe a stretched timing belt that has jumped?

Is that spark really bright and blue?


#3

So you are SURE that you have spark and fuel? If you definitely sure that you have fuel and spark the next thing I would have you do is to check the Cam timing. DO a TDC test…find the number one cylinder and line up your crank pulley to the TDC mark etc…if you jumped time you will have the symptoms listed that came seemingly out of nowhere. I am not sure as to the longevity of the timing chain in this vehicle…but a stretch timing chain could have skipped several teeth putting you out of time… YOu need to check into this thoroughly

As others have said…the Backfire…is a dead giveaway


#4

It sure seems like a timing chain or belt problem. Switching between backfire, no backfire and then starting is almost a giveaway. Have it fixed or at least diagnosed before changing every part that you can get to.


#5

Check the ballast resistor/wire if it has one.

Ed B.


#6

Check your timing would be my first step.


#7

I am starting to lead towards the fact that the icm is actually bad and the autozone test was wrong, or the computer. I will say no to the timing, as it ran fine, but higher idle than it should have when started. And it has done this to me once before but started. Ran like a top before this happened, with the exception of a couple mornings that it started, and had a higher idle than it should. I think there is an issue with the tps. I have 5 volt reference, but ground is reading something a little higher than zero, and I get no voltage swing when back probing the connector, yet the tps itself passes an olm test.


#8

Yes Sir UNDERSTOOD but the cam timing can produce the exact symptoms that you are having…The higher idle included…The timing of your distributor is directly related to and driven off of your CAM/valve timing. This is what we are trying to tell you…what was in the morning…after jumping a few teeth on the cam…will not be in the afternoon…in the timing dept both igniton as well as Cam…as they are inseperably linked together.

Do you understand how the Cam timing/Ignition timing works sir? If your cam timing is off it automatically throws your ignition timing out the window and opens up an entirely new set of repair procedures. You can no longer just address the distributors ignition timing anymore…without first checking your cam timing. It would save you a lot of troubleshooting if you first performed a TDC test and verified your cam timing. Let us know what you find in this dept. If it jumped time…you got a bigger job on your hands…

IF you verify that it did NOT jump time then we can walk you thru the steps to get it running again ignoring the cam…IF that cam timing is off, none of us can get it running for you again until that is remedied sir. Jumping a few teeth on the cam is a VERY REAL issue…has happened before…and will happen again out there somewhere…

Does the engine sound funny or off in any way when you crank it?

I just did a quick search on the net and I see quite a few instances of people with the same car and engine dealing with the cam chain stretching and jumping teeth…when that chain stretches more than the cam chain tensioner can compensate for…jumped timing is what you get…then we move to bent valves…broken valves…holy pistons and more


#9

Remembering back to my dealership days. I remember us having a lot of issues with the Mass airflow sensor which was causing exactly what you describe. We also changed a lot of ECM’s with bad solder joints. Diagnosis was pretty easy, just slap the side of the ECM and if the engine stumbled at all, replace the ECM.

transman


#10

I wasnt aware that a car would run if it jumped time? OK. So, not I am not sure how to check this. If this did happen, an estimate on repair cost??


#11

The 3.8l engines were famous for stripping the cam sprockets. When this happened the engine usually refused to start.

transman


#12

For sure, the timing chain and cam gear are the weakest links in that engine. The cam gear is aluminum and plastic. There is a cam angle sensor that is triggered by a magnet clipped into the cam gear. There are several failure modes and it is advisable to get the timing cover off and inspect and repair as necessary. It might be wise to drop the pan and clean it out while under the car.


#13

Timing was my first thought