Slow Hot Start on 98 Suburban

[mark460]

98 Suburban starts perfect when cold, but after driving and cut it off after a few minutes it acts as though it has a hot soak starter. Thinking it was the starter, I put a new starter and it still does the same thing. Battery voltage hot and cold checks out good. Cleaned battery connection to perfect clean, but still having the problem. To me it feels like the ignition is off firing or something, a few cranks very slow and then it seems to get a little better and starts. I know my cap, rotor and plug wires are old (170K miles) on them. I know I should replace them, but it typically runs very good. Any help would be appreciated.

[Blue97]

I had that hot hard start for six months waiting for it to give up the ghost. Never happened, I bought a New battery and all is good again!

[Kudzupatch]

Originally Posted by mark460

....... I know my cap, rotor and plug wires are old (170K miles) on them. I know I should replace them, but it typically runs very good.

Changing subject but YES YOU SHOULD!

I bought one with similar mileage to find factory cap, rotor, wires, etc. Replaced them and I swear it felt as if it gained 20+ hp and it probably did!

[Jeepwm69]

Originally Posted by mark460

98 Suburban starts perfect when cold, but after driving and cut it off after a few minutes it acts as though it has a hot soak starter. Thinking it was the starter, I put a new starter and it still does the same thing. Battery voltage hot and cold checks out good. Cleaned battery connection to perfect clean, but still having the problem.

My tan 83 is doing this. Would like to know what you find.

[Palf70Step]

Just took care of this on a co-workers truck. If the problem consists after battery, plugs etc and you have over 120K you are probably looking at needing a fuel pump assembly.

[mark460]

Have a new battery, starter, plugs, cap and rotor. Intake was leaking water, so I replaced the intake gasket. It runs a whole lot better now, but it still barely cranks over when it is hot. I checked the alternator charging with a voltmeter on battery, it looks good. I'm running out of ideas. Battery cables maybe? Any ideas would be appreciated.

[Kudzupatch]

Have you checked the timing? Could be it is to high, that will cause starting problems.

[mark460]

I haven't checked the timing, but I never changed it and it was running good for years.

[Kudzupatch]

That doesn't meant it hasn't changed. I am with you and I doubt it has but you seem to have hit the main things suspect. So now it is time to start looking elsewhere and it a simple check.

Other thing that comes to mind is the ground cable. If you haven't I would check that. You can have power to the starter but if it has to get back to the battery to complete the circuit. Might just need cleaning (both ends).

[pwdcougar]

Did the 98's use the timing gears with the plastic teeth? Maybe they came off so the timing is off? How about running a different battery cable to the starter?

Paul

[Blue97]

Originally Posted by Blue97

I had that hot hard start for six months waiting for it to give up the ghost. Never happened, I bought a New battery and all is good again!

Well I spoke to soon, its doing it again almost like the timing is to far advanced on startup...Cold startup is good, Just gonna sit back and hope you find your problem. Maybe that's mine aswell...

[travlinman]

Have u checked the control module on the dist.?
Ignition control module. After years of use the the contact grease wears making a almost metal to metal connection and when it gets hot it starts to act up.

[speedygonzales]

First, it would have been nice to know what engine you have. I will assume it's a 350. That means it's a Vortec and timing can neither be changed or checked in the traditional method.

You can only check cam retard offset with a proper scanner. I feel however, you may either have a fuel leak from a bad injector or a fuel pressure regulator. First thing to do is make sure your oil on the dipstick does NOT smell like fuel. The next thing to do is check fuel pressure and see how fast it drops once the engine is shut off. All Vortecs will drop to 0 eventually but the ones in good shape will take a long time to do so.

If you are leaking fuel from either of those sources, you will have one or more fouled plugs.

When I lost an injector, the pressure was at zero in less than a minute.

If all that passes, your next strategy might be to check both distributor shaft and timing chain wear by observing the movement of the distributor rotor while moving the crankshaft back and forth by hand. However, since you are good when cold and bad when hot, I am leaning toward a fuel leak. Vortec FPR are notorious for that. If so, get the new replacement spider from Standard.

[Drewkimble48]

I sure hope you don't have a walmart battery. I had one in my 86 c10 and every time I tried to start the truck after it had been running for a while, I would get a slow crank. It was also my ground cable was grounded to the frame instead of the engine. I finally grounded it to the engine and it helped it fire up each time. So it was a combo of a walmart battery and not being properly grounded. I have never had good look with their batteries period.

[jwinga]

I had a 96 with a slow start problem. Sounded like timing was advanced too far. Engine sounded like it was trying to kick back when trying to start and broke the housing on the starter. When I got a new starter it had a service bulletin in the box. Bulletin gave symptoms similar to mine. It said change the crankshaft position sensor. Changed it along with the starter and no more kickback.