Hi folks, My '87 L98 auto coupe is giving me a fit. It runs great once it starts but some times it won't start. Recent tune up and new battery. It runs within the correct temp range for this engine and the alt. puts out 14-14.2 when cold and 13.4-13.6 when hot(low?), and the oil pressure is good. This is a recent development and may have something to do with the fact that out temps here have been between 101 and 107 for the past three weeks, but I'm not sure. My problem is this, after driving and the engine is hot it will not start until it has cooled down considerably. It is a little hard to start but I have deduced from great info onother threads here that this is caused by the fuel pressure regulator, which I will replace tomorrow.I am wondering if this condition may be running the battery down or if the Bendix on the starter is just going bad and not conducting correctly, or a combination of both and the alt. is not putting out enough as well. The fact that it starts after it's cool leads me to believe it's the Bendix or perhaps the brushes on the starter sticking but, on the other hand, when this happens, if I get someone to boost it off it starts, although it has to turn over for quit some time (FPR)it still starts with a boost... bad alternator?I am going to have the alt. and starter checked tomorrow, but I fear that if they are badthey will not show as their deficiencies are not so drastic yet. Any thoughts on this would be appreciated. Thanks

For the record...I read lots of other posts about this and most spoke of the starter soliniod clicking. Mine does not even click but will start with a boost and sometimes with a wack on the starter. Also my battery shows 12.2-12.5 and drops to 11.8-11.9 when I turn the key. I think it is the starter but was just looking for some confermation.

 

My '86 has been doing the same thing! It's been 100 or so degrees here. Ran the car for a while. Turned engine off. Ten minutes later, turned the key - no start. All lights, etc came on. Just no start. Not even any starter clicking.The voltage showed 11.5 volts, and I was thinking that maybe the battery was bad. I jumped the car, andit started just fine. Let me know ifyour problem is because ofthe starteror alternator.

 

Your Bendix does not "conduct" anything. The Bendix is the drive gear that the starter solenoid pushes forward to engage the flywheel. Have you load checked your battery and starter lately while the car is hot. I bet you'll find either a weak battery or a dragging starter. Hot load on the battery shouldn't exceed 300 to 450 amps. Check your CCA (Cold Cranking Amps) on your battery. You might need to take your car to someone who has a VATS tester to check the on car load and can also load check your battery. Battery should hold at leat 9v under a 200 amp load with a full charge on it. You cannot properly check a starter off the car at an auto parts store because they cannot put the load on the starter that the car does with a hot engine.

 

Thanks for the reply Mech, I know about the Bendix, we just used to call the whole thing by that name when we were kids sort of like a generic name for the whole assembly. Not very accurate when asking for help, i know and I'm sorry?,I should have been more specific I guess, I'm really not that stupid, LOL.
The battery is nearly new, 6 months old,and tested good, not sure on the numbers he didn't tell me and I didn't ask with the battery being new and all. It is a 950 cold cranking amp battery. It checks out at 12.2-12.4 volts with a meter. The alt. checked out fine as well even if on the low side. It puts out about 14-14.2 when cold and 13.4-13.6 when hot and it wavers. At idle sometimes it will drop to 12.9-13.2 when hot(215-220) That will be next. What is the standard alternators out put amps for this '87 L98 engine? The auto parts store showed three. The Starter, amazingly enough,was the original, with 118,000+ miles, and I agree with you about testing on a bench at the local discount parts stores, they almost always tell you they are fine unless they are completely shot, but still will not work correctly when installed. We are lucky here and have an old guy that still rebuilds starters and alternators and he has this homemade rig for testing starters. No need to test this one. It was "dragging" to say the least. After close inspection of the starter and solenoid It was obvious that it was shot. The case was rusty and loose and the lining in the solenoid was burnt and scored and the spring was weak. The gears teeth were worn almost to a point with large divots in the sides where it engages the flywheel. I am very surprised it worked as well as it did. The windings in the starter were discolored and burnt from age and the brushes were almost non-existent. It would not have been long before it stopped working altogether, although it just started this acting up two weeks ago and came on very quickly.I think the three weeks of 101-107 temps here may have had something to do with bringing about it's down fall. I replaced the starter and so far it works great. Even the long cranking timesseem to be gone, time will tell. It spins right over now even when it is hot. It wasn't that difficult of a job either after I employed adrop light that worked. The biggest problem was the dang tranny coolant lines(?) Some of the wires were in poor condition as well so I repaired or replaced as needed.
Thanks again for the great help you give us here, Mech. You are a priceless commodity.Cheers

 

More than likely it is a 105 amp alternator. Best to test alternator under a load with a VATS, or something that can measure amps when a load is put on the battery, something around 200 to 300 amp load. The alternator should put out around 80 -90 amps. Glad you found your problem. [8D]

 

Thanks again Mech. I know the alternator is not original but is about 10 years old as the original caught on fire and was replaced by a Chevy dealer,according to the previous owner, my cousin. Would you suggest getting a higher out put(if there is one)or same as original? and is there any tell-tail to suggest whichthis is. I'll have it checkedwith a VATS like you suggest. It seems to be keeping the battery up, but....?
Also I'm not to sure about the statement I made about the long cranking times, it may be just that it spins over so much faster I am mistaking it for a cure. I can here the fuel pump come on when I turn the key so the relay must be good right???Just trying tolook ahead here, butif the relayis good thenperhaps it's the pressure regulator asI get no black smoke or the smell of fuel at start up associated with leaking injectors, but...???, I will check the injectors for leaking with the elimination process you described in another thread, and that should certainly tell me, but whats your best guess? And would you perhaps know of some where other than thehoses on top of the sending unit/fill that will have hose instead of pipe. Although that would be a really convenient spot to do the crimping. I couldn't redily find another spot in the lines

Thanks again for all your great help. If you ever need any custom body panels or a wing or something,let me know. Cheers, George

 

When you say long crank times, how long are you referring to? Try turning key on for a couple of seconds before cranking and see if that helps. Not sure as to what you are talking about on the filler hoses [:-], sorry. From your statement about fuel pump relay, sounds like pump is working, but have you checked how quickly it builds fuel pressure?

 

One thing I noticed about some elec. fuel pumps. If you turn on the key, wait for the pumping sound to stop, the pressure at this time is good and you will get a quicker start. May be a weak pump that's not building pressure right away. Just a thought.
Glad ta hear ya got the starter/solinoid prob fixed.

 

I always letthe pumprun till it stops before starting the engine. When I turn the key it will run for about 5 seconds or so and stop.The long cranking times are not always. but more times than not. When I first got the car it would spin once or twice and fire right up. some times it still will, but not always lately it will spin 12 or 15 before it fires.
The rubber hoses I am referring to are the three on top of the fill/sending unit that you have to disconnect to change the pump in the tank. That's the only actual hoses I could find. In another thread you explained how to crimp them with needle nose vice-grips to check the various components.
I will check pressure at the rail in the morning and see how long it takes to build and to what pressure it reaches. The manual specifies 34-39 PSI. but is that a maintained pressure or just a load pressure? I would think maintained.
As far as the pump goes ...do they make a higher volume pump. I believe I got the right one,I got it from the local dealer but perhaps they gave me one for another model,...you never know. Customer service is becoming a thing of the past...... Unless it's the girl, Julie, She's cute and calls me "sweetheart and could sell me almost anything, LOL.

AgainI want to thank you for all your help. It is greatly appreciated.I am learning quite a bit about this particular car and it's systems thanks to you and this forum. Cheers

 

Fuel pressure engine running should be around 35lbs, more importantly, it should increase 3 or 4lbs under snap throttle. Your fuel system is designed to run at a certain volume and pressure range because fuel injectors only know, open or close, and if you have to much pressure and not enough engine, you are defeating your purpose by overfueling engine.