New member - 1987 Cavalier Z24 - First Generation Forum

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New member - 1987 Cavalier Z24
Tuesday, May 31, 2016 4:55 AM
Hi all!

Long time member of Chevy Avalanche Fan Club of North America, but this is my first "vintage" car so looking for the support I know can come from other loyal owners and enthusiasts.

Bought this baby to use as a "picture car" for acting gigs and because I miss having a small manual coupe to tool around town in

Previous owner is a automotive shop instructor, so lots of quality work in this one. Wheels are from an 89? I think. 5 speed swap, NOS crate engine, paint restored to near original color. Fun to drive!

Couple of minor issues - 1st gear requires deep clutch and it stalled at stop lights a couple times on the drive home from purchase - possible low idle speed, dirty air filter (to be replaced) or just me being out of practice? Oil pressure gage inop (needle pegged high) - sending unit issue? He swapped out the digital dash for analog gages due to personal preference - looks easy enough to swap back to original (have the part) - any caveats?

Finally, any suggestions for additional tweaks to appearance to restore/maintain period look?

He included a PILE of spare parts

Thanks in advance,


Re: New member - 1987 Cavalier Z24
Tuesday, May 31, 2016 7:44 PM
Hello and welcome!! Hope you enjoy your new toy.

The oil pressure gauge on my 1987 Skyhawk is also inoperative... Turns out it's the gauge assembly itself, so I've given up on trying to find a new one.

As to the stalling, see after changing the air filter. Actually, when I got mine changed recently (and it was nasty) that's when idling problems started. Believe it or not, they were resolved by removing the ECM fuse long enough to let it reset its injection/mixture settings. And now it runs like a charm!
Re: New member - 1987 Cavalier Z24
Tuesday, May 31, 2016 8:22 PM
I would say on the oil gauge not working is maybe the cluster change over the sending unit.Normally for a good example my car the fuel gauge reading empty.You can typically just ground a bad sending unit and IF the gauge reads full on you fuel gauge your sending unit is defective.However if you ground the sending unit and it pegs the empty it would conclude a bad gauge.It could be the dash swap is reading wrong due to the ohm difference in the cluster over the electronic dash in my thoughts.I could do some research but,No 87 with a v6 had analog gauges versus the sub models with 4cyldrs.I will leave this before I over think the issue.The short answer is I think the cluster swap is making the gauge read wrong due to the ohm reading from the sending unit is not (in conjunction) with the oem cluster causing the wrong reading.If I am wrong by all means anyone please correct my logic.

Re: New member - 1987 Cavalier Z24
Wednesday, June 01, 2016 4:12 AM
ECM reset is a good idea - will give that a try. I think the stalling is not clutch-related but seems to be more related to dropping from high-rpm to low as it seems to be more related to quick slowing. Did it to me in second gear as I was turning left at an intersection. Got lucky and caught the green arrow, so went from 45 to turn speed. It doesn't cough or anything and a quick key bump fires it back up. Without the oil gage the only indication it is not running is the loss of power steering as the rpm and speed are already low. No indicator lights either.

On the gage issue, will see if restoring the digital cluster fixes it, makes sense.

Speaking of stopping... Are the brakes generally weak? Petal is firm but braking distance is awful, feels like pads have no grip. Bear in mind I'm used to driving a vehicle twice its weight and 26 years newer in parts and tech. No squealing or other obvious signs.
Re: New member - 1987 Cavalier Z24
Wednesday, June 01, 2016 7:15 AM
The gasket of the metal ring holding the filter in place is pretty deteriorated.. I don't think this filter has been changed in years. The gasket in the hood intake is in good shape, recommendations on conditioner?
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Re: New member - 1987 Cavalier Z24
Wednesday, June 01, 2016 7:17 AM
Images of engine compartment:
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Re: New member - 1987 Cavalier Z24
Wednesday, June 01, 2016 7:18 AM
digital dash cluster... looks like the traces on one side are a little damaged... think just goes to an indicator bulb
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Re: New member - 1987 Cavalier Z24
Thursday, June 02, 2016 8:30 PM
On the brake question I will suggest some ideas.i will say my 85 stops solid and firm!! I would suggest doing some simple remove and check then the next step.I would first check the rear drum brakes as these are lack luster for great quick stops but,will do the job.I would remove the drums and look at shoes,how much brake dust is in the area on the components and check the wheel cylinders for any kind of residue of brake fluid.Next when you apply the emergency brake is it a few clicks up or all the way?This can be 1 of 2 things.Either a adjustment is needed in the cable Or the cable could be stretched.I have to add the 3rd item if the brake shoes are worn down this makes the e-brake travel further to tighten.On the front disc I would suggest check the pad thickness and even go as far as removing the caliper and checking the slide pins for dryness and the piston for a worn rubber seal on the caliper itself.I would also suggest checking the brake hoses front and rear and is your brake fluid (black)?If it is not clear it needs to be flushed.As long as there are no visual leaks at the master cylinder outside the car and especially inside the car at the piston rod from the brake pedal to the master that should be fine.If any of these components show wear or suspect to needing a update I would not hesitate to just do a complete front to rear brake restoration and bleed the system to bring it up to par if it is unsatisfactory upon a good inspection.I realize the car is older and yes today's newer rides handle great and do not always hold up in some applications in comparison.Believe me if you have worn rear drum brakes or you have calipers that have sticking slide pins or a sticky piston the braking is far less and even leaky wheel cylinders or just tired parts.I tried to be objective and provide a complete detail of what I would do before I bought any parts and did the changes.I forgot 1 item check the front rotors for visual defects the surface should be smooth!!!! No grooves and or certain wear points or even hot spots.Done.

Re: New member - 1987 Cavalier Z24
Friday, June 03, 2016 3:32 AM
Thanks for all of the ideas! The e-brake does pull really high up, but holds firm and stops the car while in motion. No shimmy or pulling while braking so I don't think the front rotors are warped (unlike my Avy, which has a bad vibration when braking at 50mph). I'm going to conclude from the e-brake travel and the box of new shoes that the rear drums need work. Will also lube front caliper slides - I've got the stuff as I've been planning to do a 4 wheel brake job on the truck... Woo-hoo two brake jobs
Re: New member - 1987 Cavalier Z24
Saturday, June 04, 2016 7:35 PM
When I bought the Skyhawk, e-brake handle felt loose and pull all the way up, high enough to lift the armrest actually. I quickly realised it didn't hold at all. Turns out it just needed adjusting. Now the handle feels very firm, only goes up two or three clicks or so, and it actually holds the car. The rear drum brakes needed to be serviced too anyway, when I got the car breaking resulted in a some kind of lock-up at the rear and a lot of instability.

Lemme tell you, with all new shock absorbers and serviced rear brakes, it feels like a brand new car!! Front brakes will be due for service soon too, in termes of mileage, but they still work quite good. Got some fade, lack of bite, a tiny bit of whistling, but very stable, straight, can't imagine how good it'll be when they're new too.
Re: New member - 1987 Cavalier Z24
Wednesday, June 08, 2016 5:28 AM
Hi Dave, you may want to check with the previous owner and make sure that he swapped out the prom for the ECM if it is still running on the automatic ECM prom that could be part of your stalling issue. I believe the idle values and such are different from the automatic to 5 speed prom the motor will still run but will not run Optimum. Good luck, Roger.

Re: New member - 1987 Cavalier Z24
Wednesday, June 08, 2016 6:30 AM
Is there a code sticker or other way to determine if an ECM module is AT or manual? I have one or two spares. He claimed to have driven it daily on 200 mile round trip commute, so I suspect the stalling might be a combo of dirty air filter and bad gas from sitting. If it was ECM wouldn't it be difficult or at least annoying to deal with daily?
Re: New member - 1987 Cavalier Z24
Thursday, June 09, 2016 4:39 AM
Sorry, I wish I knew more about the proms. I know the car you are talking about though, it was posted for sale on for a while, some of the guys over there are very knowledgeable on the proms and what they are marked. I just know that the idle values are different from auto to standard and that can cause a problem like stalling when pushing the clutch in or coming to a stop, not saying this is your problem but you don't know which prom is in the car right now. You can read the auto to manual 5 speed swap sticky thread there and I believe that the chip issue is mentioned in it. Good luck, Roger.
Re: New member - 1987 Cavalier Z24
Monday, June 13, 2016 4:36 AM
Here is a site to decode the ecms. It was started by a former member on here that did a lot of heavy mods to his 4 cyl.

Re: New member - 1987 Cavalier Z24
Tuesday, June 14, 2016 6:25 PM
The gasket in the hood intake can be conditioned with 3M Silicone Paste. It is pretty expensive, but is great for use on rubber, window channels, wiring connectors, brake caliper slider pins, etc, etc. It goes a long ways too, so a bottle should last you for years.
Re: New member - 1987 Cavalier Z24
Wednesday, June 15, 2016 6:12 AM
Any idea what your oil pressure really is? My Pontiacs & Buicks have a dual circuit oil pressure sensor. One side is for the gauge, the other side is a switch for the fuel pump. The ECM tuns the pump on for starting, then lets the oil pressure switch take over to keep the pump running. This is a protection circuit to save the motor if you lose oil pressure. When you take yer foot off the gas to slow the car, the OP could be dropping off to the point that the F-pump turns off.


82 Skyhawk Convertible:
83 P/2K Turbo:
86 Firenza Cruiser: "Jack-Wagon"
87 Skyhawk Custom:
90 Sunbird GT: "Turbo-Turd"
93 Sunbird Convertible: "FrankenBird"
(and a pair of Cavaliers I'd rather not talk about)
Re: New member - 1987 Cavalier Z24
Thursday, June 16, 2016 7:10 PM
I just put the analog cluster back in - I managed to hook up the oil pressure sensor wire correctly and am getting an appropriate reading on the OP gauge under idle. I've lost cluster illumination in the process, so a test drive will have to wait until tomorrow.

The digital dash appears to be damaged - nothing from the "digital" gauges or the speedo/odo... Only some indicator lights.
Re: New member - 1987 Cavalier Z24
Friday, June 17, 2016 10:30 AM
Dr. J-Body -

You are on to something there - now that I've got a functioning oil pressure gauge (not claiming accuracy just that its relative response is appropriate), I can see the oil pressure is barely above zero when there is no load on the engine. OP plummets instantly when I'm forced to hard brake or quickly reduce speed: stalled going 45 to near 0 this morning, even with dropping out of 3rd to Neutral (had at least that much reaction time). In that instance I know it wasn't drag from the tranny or clutch.

Oil level seems good, no apparent leaks, next step in my mind is to sea foam the crankcase then get the oil changed. Unless there are other things to check first? It always fires right up with a bump of the key when this happens.
Re: New member - 1987 Cavalier Z24
Thursday, June 23, 2016 9:04 PM
Your oil pressure switch or sending unit from Auto zone is PS212 I would double check your part and LOOK at the auto zone webpage as I checked numerous times even being tired.Your sending unit is a single terminal and based on the choices this should be the correct application.Just go to the page and YOU have to choose a location and then enter your cars specs Year,brand,model and engine.I checked advance auto but the units they show could be one.Auto zone did show the in my opinon correct part for your application.The humidity and sun just wore me out today in the yard after 6 hours outside.I amd just doing a Quick search and pointing in the right direction.I will assay there are 4 choices .Being you reinstalled the electronic cluster the sending unit has to match the cluster in terms of (OHMS) how it reads the sending unit.A mechanical gauge and or dummy gauge has separate sending units versus the electronic clusters.Based on your picture 1 terminal and the part descrbied I read this should be correct sir!!

Re: New member - 1987 Cavalier Z24
Monday, August 29, 2016 10:05 AM
So, after some going back and forth on research, and obtaining shop manuals for both 87 and 89 cavaliers, here is where I'm at:

1. Knock sensor was damaged (broken connector) AutoZone SU168 if anyone cares...
2. OPSU was not only bad, but appears was a modified PS168 - the harness has a single socket, so someone just cut the side pins out. Installed a PS212 and am getting good oil pressure readings at all temps.
- this indicates to me the OPSU is not connected to the fuel pump, but only to the gage in the cluster (one wire, not 3), so ruling this out
3. Engine is still cutting off when engage clutch when engine is hot. Since I know it is coming, if I goose the throttle a bit before I clutch, it prevents the cut off.

4. It isn't stalling the engine due to clutch drag, as the cut off happens in neutral as well as in gear

5. PCV appears to be good
6. MAF appears to be good
7. TPS appears to be good
8. EGR appears to be good

I worked with a guy who has created an ALDL tool, so I can read the computer live. There is no VSS signal going to the ECM, which is a byproduct of the analog cluster. Haven't determined the correct connection for that.

I'm now turning towards the issue being fuel system related... Any suggestions where to check next? Would bad injectors do this? Codes or conditions in computer to look at?

Thanks for the assist!
Re: New member - 1987 Cavalier Z24
Tuesday, August 30, 2016 9:29 PM
Tired I am but will follow up.I worked on a car all afternoon in the heat and fried.

Re: New member - 1987 Cavalier Z24
Wednesday, August 31, 2016 8:51 AM
Clarification details - gave up on the digital cluster, as it is non-functional. Analog gages cluster remains. Speedo is cable-driven and since this is now a manual transmission car, there is no need for VSS to ECM, as there is no TCC to speed match and no cluster to drive.

I'm pretty positive the Mem-Cal in the car is for an 87 Z24 A/T. Hypertech has a proper chip and I'm considering the thermomaster version and the 160 thermostat kit. I'm not convinced the ECM is causing the issue.

Other thoughts... Clogged fuel filer or injector?
Re: New member - 1987 Cavalier Z24
Wednesday, August 31, 2016 5:33 PM
Replaced the IAC, was in stock at the local AutoZone, old had a lot of carbon build-up and a dried out o-ring.

Can tell the new IAC is in there, but still getting the cut-off issue. No codes.

It almost acts like the fuel is getting cut off by the ECM for deceleration (which according to the manual is normal), but it's not recovering quickly enough every time.

Would an auto transmission Mem-Cal in a manual transmission car cause this? I really don't want to drop $170 on a third-party chip...
Re: New member - 1987 Cavalier Z24
Wednesday, August 31, 2016 10:00 PM Try this as I spent the afternoon yardworking and toast.Being you have a 2.8 it in my opinion would have to relearn the idle and run smooth.I will do some rechecks in my books to see if I am missing something.Granted with the wiring and changes it could be several other things like the egr,map sensor,maf sensor and not a far stretch the coolant sensor and or even the cps (crankshaft position sensor) that could create idle issues.These first gens are not to over complicated but the diagnostics take some time and when one is tired from being outside all afternoon the ideas can be cloudy.Ok

Re: New member - 1987 Cavalier Z24
Thursday, September 01, 2016 3:34 AM
Thanks Ron,

I did the IAC relearn process before I posted my update (which is how I knew the new IAC was working).

Next on list is MAF... There were 3 extras in the included parts, but the computer output appears correct.

It really doesn't act like it is hunting, it's like stepping on the clutch when RPM is over 3000 and the fuel is cut off. If I goose the gas before I clutch, it doesn't cut off.
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