Took the 89 out of storage about two months ago - fired right up with no problems. Drove a little over 30 miles, stopped for lunch - came out and would not start, engine would turn over but not kick in. Ended up towing home and have been working the issues since then. Car would start if we shot some ether into the intake. Would not keep running.

Decided to do a major tune-up: replaced the following - new MAF, new plugs, new wires, new rotor, rotor cap, ignition coil, new 02 sensor, new pcv valves, new egr valve, rebuilt gas regulator, new fuel filter (drained all the old gas and replaced with new), cleaned plenum of carbon buildup, checked injectors and replaced the seals. Put it all back together and.......................

Tried to start - no go - would run a bit on ether.

Then checked all the electical connections - all good, to include all the fuses - tested each circuit. Noticed a lot of heat from ECM under dash - so we replaced that as well.

Did a compression test - no problems

Checked all the vacumm lines - apparently the previous owner decided to jury-rig the lines. (this car ran great for the 10 years I have owned it. Some vacumm lines were blocked off and some were wide open. Now we are running the vacumm lines as they should be done.

We can get the engine running but real rough and not for long. You can understand why we are frustrated. The guy doing the main work (most of it) is GM trained (now retired) and has all the tools and diagnostic tools we need. Has him at a mindblock.

Only line we cannot find a diagram on is for the brake booster - not sure from where it is to come from??? Local Chevy garages will not help out even for a few questions.....

I do have a diagram showing the routing of the vacumm lines in the engine compartment but not for the brake booster. Any help appreciated.

ALSO - any ideas as to where to look/fix/replace next??????

 

Sounds like you've got a fuel delivery problem.

Any stored trouble codes on the computer?

If your running the stock '89 non ethenol compliant fuel injectors those things have a mind of their own and have caused many problems for their owners. Long story short: the injectors may ohm out OK and fire with an injector bench tester but the ECM won't trigger them under normal circumstances.

My recommendation is change the fuel injectors out for an ethenol compliant set.

 

Did you guys check the fuel pump?

 

You've probably bought a bad ECM or forgot to place the memcal in the new one.

 

First thing I would do is check the fuel pressure. The vacuum for the booster comes from a port between the runners of cylinders 3 and 5 (I believe) on the intake manifold.

 

always a good idea

 

If it starts with ether, it sounds like a fuel delivery issue.

 

Fuel pump is good, fuel pressure is 40+ and holds, ,memcal was placed in ECM, only code (initially) was for a bad MAF.

Noid light placed on injectors - all firing

 

Side note: regarding the fuel - we 'doctored' the fuel with octane booster - only put in 5 gallon of gas and about 4 cans of booster, so the ethanol issue should not be a problem.

Thanks

 

The injectors are getting pulses, but are they actually firing?

 

Right, most definitely a fuel pressure issue. You said the pressure is good, but have you tested it under load? Also, check those injectors! looks like you've replaced everything but those...

 

When engines won't run you ALWAYS check for the 3 fundemental things that ALL I.C. engines require!!!! Engines need hot spark and spark at the right time, they need fuel and air and in the correct ratio, and they need cylinder compression.
Your engine ran with starter fluid, this tells you that you have spark but no fuel! First measure fuel pressure on the shraeder valve on the end of the right fuel rail. It should be 35-42 psi and it should hold up during cranking to start and it should hold up for at least a half hour after the ign is off. Fast leak down tells you that you have leaky injector/s or a defective check valve on the fuel pressure regulator. You can measure the resistance (16 ohms) of the injector coils, but that will only find gross coil errors. The definitive electrical test on injector coils is done with an impedance bridge which measures the inductance and the Q of the coils. An ohmeter cannot find a turn to turn short, but a bridge can and injectors will not work with a turn to turn short! Also, the injectors MUSY spray fuel and the only way to tell that is to look at them when they are spraying fuel.

 

What injectors do you have? OEM?

 

when the engine is trying to start, monitor the fuel pressure gauge. you should see the gauge dip to almost half the pressure as each batch of injectors are firing.
If not, your injectors aren't actually moving internally. Check for a bad engine ground.

 

Hello> Had the exact thing happen to my 89 too. Replaced pick up coil, ignition module, compactor, rotor and dist cap, and the car runs fine.
As the one member said every engine needs spark, fuel, combustion.
JR

 

just for laughs you may want to see what the temp sensor is reading. this could drive you to lean to start or flood you out. Just something to check.

 

The brake booster line connects to the rear corner of the plenum near the distributor. I agree that the injectors could be the issue here. Try pulling one injector plug at a time while it is running. If it instantly smooths out, then you found the bad injector.

 

Checked injectors how? Fuel pressure and ohm readings still won't tell you anything about actual spray patterns. The fuel needs to be atomized to burn right. If you injectors are spraying solid drops of fuel because they are dirty/plugged the car can't ignite the fuel right or at all depending on how bad and how many.

The fact that it started at all with a shot of ether into the intake clearly indicates a fuel problem. And the fact that it won't stay running after that might also be related. If you have not already done so I would be curious to see the injector spray patterns. The only way to see that is to either remove them to have them bench tested and pulsed under pressure or to remove the runner & plenum and suspend the fuel rail while dipping each injector into a glass jar with fuel lines still attached and tach wire on dist cap connected. You can do this with some fuel line fittings and rubber hose with clamps between the rail and car's lines.

Remember that too much gas will also prevent a car to not start when hot but will still start with some carb cleaner or starter fluid into the intake.

 

Thanks to everyone for their input - taking a break of a few days before going back to the vette - printed all the responses out and will review them with the mechanic - he suggested a few of them yesterday. Hope it works

Thanks again to all

 

The vacuum port for the power brake booster is a dedicated line directly from the plenum just past the runner for #7 cylinder to the brake booster itself. I've attached a terrible drawing from the FSM as a guide, but you should be able to see it on the car. My 89 has a bracket attached to the read of the driver's side cylinder head holding the line in place. Hope this helps!