88 carrera need help

[radelizi]

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Thank you for your wisdom in advance. I have a 1988 targa that I have struggled with for the past 5 years. Much of the time it sits in the gararge 99.9 percent of the time. I have an abundance of issues and wonder if they can be some how related. It wont start sometimes. When it did, the idle would hunt, the engine sounded like it was strugling. When driving, The engine would have to be reved so that it would shift in upper rpms, or else the tranny would not shift until the rpms fell below 3000. The brake pedal is very stiff. I would play with wires below the key ignition and some how it would start sometimes. Whenever it get s wet out or I wash it, it wont start for 30mins. Now there is no spark at the coil and just cranks. When you try to start it you have to turn the key ignition to off before you can try again. Fuel smells strong when cranking. I had an alternator go bad in the middle of this last year.(voltage regulator). There is a steve wong chip in the car. All the fluids are new, and calipers not hung up. Any ideas? What about this speed sensor talk, what about bad ignition? Would that effect the clutch function in an a g50? CHT tests good. New 02 sensor, ignition wires, cap and rotor. Thanks so much, If you decide to give me some advice.- Ryan

[scarceller]

OK,

You posted a boat load of issues! But let's start with your no start issue first.

Turn the key to 'RUN' but don't try starting it. Then right in front of the Throttle Body you'll see the Idle Control Valve put your hand on it to see if it's vibrating or listen for it humming. It needs to be humming and vibrating, if it is this means the DME is alive and well.

Test this first and report back.

[kodioneill]

Take the car to someone who knows what they're doing.

[scarceller]

Also, I suspect you may have a large vacuum leak. Low vacuum will effect the Power Brakes and the G50 clutch. A large vacuum leak will cause you to run very lean so I suggest you do NOT apply much load (Throttle) on that engine till you resolve your issues. Read my prior post so we can see if we can get you at least a running engine first.

[CCM911]

Originally Posted by kodioneill

Take the car to someone who knows what they're doing.

Best advice ever. It is clear that you are new to all this, so I would buckle down and spend a few bucks. I am not saying that you have to have it all repaired, but wouldn't it be nice to have all your issues spelled out for you?

[Quicksilver]

Location, location, location...

Add a location to your profile so people can tell where you are and what resources are near you.


Have you picked up a Bentley manual? You need to work through the issues one at a time.

[radelizi]

Thanks all. There is vibrating at idle control valve.

[scarceller]

Do you have spark? Disconnect a spark wire then add a test plug to the end and ground it to a good ground point with Vise Grips, crank and see if it sparks.

You also need a good 12vdc LED test light, it MUST be an LED type. You can get one for about $5.00 at Walmart. We'll need it to test Speed and Refrence sensors. Do you know where these sensor connectors are?

Where are you located?

[carsinc]

This is not a Chevy, needs to be taken to a Porsche Pro.

[E Sully]

Are you the patient mechanical type? If you take items one at a time you can eliminate some of the issues.
If the brake pedal is hard, I would think there is a vacuum leak affecting the booster. This would also affect the idle and running by leaning out the mixture. The rubber section in the picture can crack and leak, and the brake booster line connects to the section just to the left of the box. Also look around the engine compartment for any hoses that may be loose or off the fittings. Try and snug up the intake manifold lines with a long allen key.

You have already installed new spark plug wires, rotor and cap. Make sure all the ignition leads are securely pushed on. You could also remove the spark plugs and see if they are all firing. Besides a vacuum leak, if all six cylinders are not firing, this could be part of the running issues you are having. Sometimes an injectors solenoid sticks from sitting and does not spray.
You have a new CHT, have you checked the resistance at the speed and reference sensors?


The playing with the ignition switch wires to get it to start could be a mechanical problem with the switch, a poorly connected wire, or a worn electrical part of the switch.
Here is a link to the mechanical problem that occurs.
Ignition switch fix--mechanical
Open up all the electrical connectors and make sure they are clean of corrosion and reconnect.
You have a Targa, does water get in by the DME under the drivers seat?

[scarceller]

Ed, funny you point out that vacuum hose, mine broke in that exact spot as well.

[scarceller]

If you know where the speed and ref sensor harnesses are then test each sensor's resistance with an ohm meter. They need to be 800-1200ohms typically around 1000ohms. These usually go open circuit and read 0hms, test them both.

Then later we'll test them while cranking with a LED test light but first do a resistance check.

Also do a simple spark test as well. If you have spark then these sensors are working.

[scarceller]

One more common failure is the AirFlowMeter carbon track but we won't go here yet.

[OK Porsche 911]

My personal experience with problems you are having could lead back to a poorly installed aftermarket alarm system. Does your car have such a system?? Four of the last five 911 I have owned had some sort of start / run problem, (the fifth car didn't have an aftermarket alarm and had no problems). Look under the dash in the area of the ignition switch and check to see if some wires have been spliced into the switch wiring. Hint; Playing with the wires under the dash. Loose connections, wrong sized wiring, junk alarm systems, or just plain old shoddy work make an unreliable alarm. Some alarm systems kill the starter, some kill the ignition system. If you still have problems, AND I think you have several, I would find a good Porsche shop and let them diagnose the problem. You can do the repairs yourself, if you like.
==GOOD LUCK ==
A Porsche that SITS in the garage isn't nearly as much fun as one that you SIT in driving!

[Chuck.H]

Originally Posted by scarceller

Also, I suspect you may have a large vacuum leak. Low vacuum will effect the Power Brakes and the G50 clutch.

Sal's advice is usually spot-on... but vacuum affecting the G50 clutch??? AFAIK, it's not boosted like the brake M/C.

And I'm a little surprised by some of the other comments - "it's not a Chevy?" no it's WAY more simple! When I've used GM ECM's in the past, I was amazed how much more code they contained in the same era. ECM controlled A/C (for idle stabilization), knock sensors for ultimate timing, etc.

Anybody with patience and a few tools and common sense can fix these cars, esp with the entire internet backing them up!

Good luck OP,
Chuck.H
'89 TurboLookTarga, 346k miles

[scarceller]

Originally Posted by Chuck.H

but vacuum affecting the G50 clutch??? AFAIK, it's not boosted like the brake M/C.
Good luck OP,
Chuck.H
'89 TurboLookTarga, 346k miles

Chuck, the DMEs I know inside out but the G50 I'm not an expert in so I made some bad assumptions. Thanks for pointing out that the clutch is not vacuum assisted.

I think he has several issues going on not just one.

[Storage Man]

My girlfriend has pointed out on several occasions that I also like to fix things until I break them more...
Get a pro involved...get the do no harm issues identified first...work out a paymnet plan if needed....

[Quicksilver]

I'm betting on multiple vacuum leaks and a big one in the hoses that end up up front for the power brakes.

Where Sal pointed to the rubber was cracked on mine but no leak yet. I had breather hoses that had hardened so much that one fractured into multiple pieces when I tried to reinstall it.

I "was in there" to fix multiple cracked intake gaskets...
- Which led to crumbling intake insulators...
- - Which led to replacing failing fuel lines...
- - - Which led to finding the cracked rubber on the vacuum line.

-----
With the age of these things you should expect to need to replace the rubber hoses.
- Replacing the fuel lines with something safer and more permanent is just prudence.
- Checking the torque of the intake nuts is a normal checklist item on these cars. (18ftlbs)
- If the intake has been loose then expect that the intake gaskets would have cracked. You can often detect intake gasket leaks by starting the engine cold and using an infrared thermometer on each exhaust port and look for one (or more) that isn't heating up.

You have some things to check on the car...

[scarceller]

Best way to find intake leaks is smoke machine, many shops have this and charge very little for the test. Nice thing about this test is the engine is off.

2nd best is start the engine and use starter fluid carefully in the suspect areas. I also have used propane tank with a hose, you'll be amazed how quickly a air leak will suck in propane.

[EMJ]

As others have pointed out, take it to a Porsche mechanic. Fixing stuff on these cars isn't too bad, but the diagnosis can be tricky. A good mechanic will give you a good punch list of issues to repair. Many you'll be able to fix yourself, but at least you'll have the information in front of you to decide.