SPFI EA82 Idle Stutter and Rattle

[SuspiciousPizza]

'89 GL SPFI. Has had an idle issue since I've bought it (6 months ago).

RPM's will flutter approx plus or minus 25 RPM with idle set to 750 RPM. It will continue to flutter until 1250 RPM. Along with this is a rattle-tick that is too fast to be a cam or lifter (the noise comes from the center of the engine). 

It will stall when cold unless I keep the accelerator held above 1000 RPM until the needle reads just above cold. RPM's will not increase when cold, it wants to but it sounds like it bogs then catches itself, leading to a loping-idle.

What's been replaced:

Plugs, dizzy cap, rotor, ignition wires, coil, IAC valve, coolant temp sensor, thermostat, radiator cap (this has helped the issue, but it still lopes)

My ideas:

Timing issue, water in the fuel system (it sat about a month while doing full suspension work), some sort of vacuum leak (haven't tested with a gauge), fuel pump or injector issue, a computer issue, a ground/harness issue

 

Any guidance or pointers? Hope you enjoyed the novel :] 

 

[moosens]

Short novel, you’re a good author. 
 

Tough call be you seem to have covered a lot already. CTS is often a culprit. You’re sure , even if it’s new , that it’s a good unit? 
 

Vacuum lines come to mind too. Always need a tight fit at all junctions. 
 

O2 sensor been dealt with that you know? 
 

If it runs well at any point chances are the timing is fine. If you put your foot into it and the engine is smooth then I’d not worry about timing. Although the one aspect of that to be sure of is the belt tensioner. With covers off crank it by hand with your 22mm if you want to feel secure about timing. Check your marks. And feel and note the tensioner doing its job. 
 

But it would seem more fuel/air/spark rather than crank/cam timing. 
 

Another item to check would be your distributor. Take the cap off and feel for excessive up and down play or side to side play when you grab the rotor. 
 

Try checking over all that and let’s see what you find. 

[moosens]

Not trying to me mister sales department here but I do happen to be cleaning house of decades of Subaru life and currently have a set of factory timing belts on eBay. My name there is cashingmystuffin 

I don’t have much 80’s parts left but as they show up I’ll post them. The listing for these belts looks kind of crude because I just tried to help someone who wanted a buy it now option. Turns out I did this auction as well as the item he wanted. Was that you? Did you just buy that timing kit I had ? If so I’ll be digging that out tomorrow. 

[el_freddo]

Make sure your CTS isn’t installed with Teflon tape. It may need the earth/ground of the coolant passage that it’s screwed into. 

I’m unfamiliar with whether this needs an earth connection. I mentioned this as the brumby/brat used a temp switch in the radiator to trigger the thermo fan. Put Teflon tape on this and it doesn’t work as it requires the earth/ground provided by the radiator (that also has its own earth wire from it to the body). 

Other than that I’m out of ideas. 

Cheers 

Bennie

[SuspiciousPizza]

I did not purchase the belt kit, but if you have any OEM CV's up, then I've probably at least looked at them, been buying those like crazy lately.

The reason my car is sitting is I blew the passenger DOJ boot, which sits right above the cat for some reason (can't imagine that's good for the grease nor boot.) So I'm taking the time to address old gremlins.

I'll check the CTS, dizzy, and vac lines (I should be replacing those and their fittings anyways since I'm pretty sure the fittings are almost all original. But the rat's nest has always appeared intimidating.)

I have a continental belt kit which has new idlers and I believe I have a new OEM tensioner as well, so I'll be checking that too. 

New fuel filters are on the way. Under hood one was WIX and I've seen others on here lamenting about them.

Could it be an intake boot issue? I have a new-used one on standby.

:] Noah

[SuspiciousPizza]

Quick check of CTS, dizzy, and belt.

CTS: Solid ground, 0.5 ohm resistance to ground. Haven't done the water temp test yet as I don't want to drain coolant for the umpteenth time if unnecessary.

Dizzy: I can rock the car by the dizzy rotor. Dizzy seems solid in it's mounting.

Belts: Uh-oh! I can deflect the belts with one finger (see images for where the most play is) I know belts have a high-tension side and a low-tension side but perhaps my belt has stretched beyond limit?

 

I have a factory service manual to follow, but any belt service procedure in layman's terms would be helpful as cross-reference. 

:] Noah

[moosens]

With the car running spray so carb cleaner or wd-40 around the suspected intake gaskets and carb base. See if that makes any change in idle. 
 

Yeah looking like time to change pulleys etc 

[moosens]

That crusty return spring on the belt tensioner could use some help. Guessing the tensioner pulley pivot could be sticky too. 
 

Check that manual and see how much belt deflection there should be. 
 

 

[SuspiciousPizza]

Replaced the timing belts, tensioners, and pulley. All went well. 

Started up, but I still had to keep my foot down. When I lifted my foot it did it's "normal" flutter idle at 250 RPM whereas before it was at 750 RPM (before it'd die below 500 RPM so small victory). Loud clicking from the center of the engine still there.

As I went to go check on the clicking, it was PISSING coolant from the radiator cap. Well that's new. Could a head gasket issue cause the flutter and coolant leak? 

I'll keep posting as I chase this cornucopia of mysteries. Any suggestions or ideas are always welcome.

 

:] Noah

[SuspiciousPizza]

I believe the coolant leak from the radiator cap was caused by a worn plastic lip on the radiator. 

In the next few weeks I'll be doing a pressure test on the coolant system and a smoke test on the intake and vacuum system, as well as verify my timing (just gotta wait for the tools).

 

More blurbs to come in a few weeks. If I don't see ya before the end of the year, happy holidays to all!

:]