88 GTA - 5.0 TPI

So, here's the low down.

The last two weeks my car has gone from running like a raped ape / to stuttering and backfiring like crazy. When it does backfire like crazy, I notice that my RPMs at idle are around 1400 and that my oil pressure is extreamly high. Kind of like they are when you first start your car with a cold engine. Scenerio 1.

Car is running like hell. I limp it into a chicken wings place to vent over some large 34oz beers (but not too many). 2 hours later, I walk out - turn the key - and it runs fine.

Thats what I find most frusterating. The good running / crappy running changes. This has been going on for about two weeks now but it could have been showing symptoms from much earlier.

In july I took my car out of storage and had it shipped down to Texas where I now live. I drive it to my place and shut it off. The next day - no start. It cranks and cranks but never attempts to fire the engine. After 5 days of it not starting I have it towed to a shop where as it starts immediately. No problems discovered.

What could be failing here? Idle control valve? Temp Sensor? Any ever see any symptoms like this before?

As of right now - she's stuck at the grocery store. And I haven't much an idea what to do with it. I guess I will now watch my Lions lose badly and pray for another miracle rebirth.

Any direction would be appreciated. Thanks guys.

 

n engine with EFI doesn't have a choke, so it's not that. Cross that suspect off your list.

An engine needs 3 things to run: air & fuel in reasonable proportions; spark at the right time; and compression. Consequently a no-start condition is incredibly easy to troubleshoot: you've got 3 ingredients, odds are only one is missing, all you have to do is figure out which one and zero in on the culprit. Pretty simple. I'd rather try to figure out a no-start as compared to a runs-like-crap ANY DAY, it's just too easy.

So, think about it. Do the process of elimination (in the bathroom even, if you need to). What could cause your engine not to run? One ingredient at a time.

Eliminate compression first. Odds are VERY VERY VERY LONG against having compression one minute, it going away to the point that it won't run the next, and then suddenly returning. Very un-compression-like behavior. Eliminate that one.

That leaves air/fuel, and spark at the right time.

Air, you probably have. Eh? How about fuel? If fuel is the only thing missing, then all you have to do is supply it, and the engine will run. Eh? Do it. Spray starting fluid into the intake WHEN IT'S SCREWING UP AND WON'T START, and then try to start it. Either it will start, or it won't. If it starts, then fuel is the missing ingredient; investigate the fuel system: relay, filter, pump, in that order.

If it still doesn't start after the above test, then it probably has no spark. Investigate the ignition system. Plugs and wires won't fail, then suddenly work, then fail again, to the point that the motor won't run. On the other hand, things that are common to ALL CYLINDERS, might. Investigate the rotor, cap, ignition module, coil, and pickup coil, in that order.

Note that at no point do we blame the ECM, invoke voodoo, change sensors (NONE of which can cause a no-start), or anything of the kind. We use logic, reason, discipline, and brainpower. It's easier and faster than anything else available. See my signature for helpful troubleshooting advice.

If I was the guessing kind, I'd guess that it will turn out to be either the fuel pump relay, the rotor, or the ignition module; or possibly, faulty primary (12V) wiring feeding power to the distributor.

It's also possible that you have a HUGE vacuum leak, like a cracked hose (power brakes or PCV).

 

No doubt good clues. Any idea why the idle has been high as well as the oil pressure? This seems odd to me.

 

Oil pressure at idle will be high if the idle speed is high. No riddles or surprises there.

You may have more than one problem: vacuum leak causing high idle, and something else causing the no-start. I can't think of ANY possible defect that would account for both behaviors.

Fix the no-start first. Then worry about the high idle (which almost certainly IS NOT the IAC) unless you come across something glaringly obvious during your no-start troubleshooting, like a broken hose or some such.