DWC4

150K miles, just had a new Optispark, running well. When cold, turns over almost instantly, but when I start it soon after stopping it, cranks awhile. Not terrible but a lot slower than when cold.

I don't think my 92 has that Cold start valve (88 and earlier only) which is all I've seen other than general fixes for this. I have had my fuel pressure checked as part of diagnosing that my optispark died some months ago, all ok (I'm told by mechanic).

In general, since these are still the original parts, I'm planning to replace:
- multec injectors
- 02 sensors (2 on my car, one IN FRONT of each Cat)
- coils maybe since they're so cheap
- Mileage is not what it once was, and these plug wires and plugs are now at about 75K so they're on the list as well.

'your thoughts'? THANKS

BADDUCK

Do you mean it cranks slower or takes longer to start when warm? You do not have a cold start injector. Why plan on replacing things unless they are proven bad. You can start by checking ohm readings on your injectors against spec. If they are good look elsewhere. If it cranks slower when hot it could be the starter.

L71Maynard

I had a similar problem in my '92. The problem was that the injectors would leak after driving the car and would cause the engine to crank more when hot to get it started.

Dave

96GS#007

Pull the vacuum line off the fuel pressure regulator. If there's fuel in the line, the FPR is bad. Pretty typical symptom is slow to start when hot. May not be it, but worth checking.

BrianCunningham

Any codes?

check the temp sensor connectors

Check you see if the two, digital & analog, temps agree?

Jesse

Rule review:

Answer the question for the OP without attacking each other's replies, credibility, or tenure ...

FICINJECTORS

thank you Cor08, most of us are trying to do that..

BADDUCK

You mean like this? I agree!

BrianCunningham

jaa1992

We are trying to save you some money and aggrivation.

Do the FPR check.
Ohm out the injectors hot and cold, a DVOM is $5.00 and you will use it - alot
Jon at FIC is the man for getting your injectors rebuilt or a set of bosch 3's
FYI - I don't think ours are the dreaded multic injectors, they were used on the older l98's.
Its probably one of those issues.

I had a problem with heat soaking my ICM, someone suggested taking a few washers and putting them between the head and the ICM/Coil mounting plate. I don't know if it was that or the dewitts radiator that has kept my problem from comming back.

DWC4

If someone here has a problem with my posting, tell me ok? Or buzz off.

I've been a forum member a couple years and try to use it in the spirit it was meant to be used. Thanks for the help to those of you who have given me tips here, it's appreciated.

I've kept this car going for 17 years and 150K miles, and I'm in a gradual process to return it to 'like new' - in performance and reliability first, and in appearance later if that all pans out.

Facts:

It's a tested, good new battery, relatively NEW starter, it cranks fast always; it just takes longer to actually START when hot. And it runs and even idles well (ever since the recent new Optispark) but it could run better and get better mileage, both have deteriorated.

If it can start within 2-3 seconds when cold, it can do it when hot if everything is right. It used to.

It's due for plugs and wires with 75K on this second set; I've seen plug wires do miracles on these cars but that's not a starting issue. But the same plugs and wires start it cold or hot, shouldn't be the cause.

I've tested the injectors with a digital meter, all within spec, and also am already in touch with Jon at FIC, and he has made a part# recommendation to replace my Multecs, something I've planned to do but other issues get in the way. They could be leaking, etc. He also recommended 02 sensors replacement and a fuel filter, both due given 150K miles and even if not required, worth doing for the little cost and work involved. (actually don't remember my last filter change...)

I like the ICM idea, worth trying, thanks, cant' hurt; as are the tips on fuel pressure regulator.

At this stage in its life I'm gradually replacing those parts that are reasonable in cost, reasonable in labor, even if they haven't failed yet. Or unreasonable cost, but must be done on a schedule (timing belts and such).

I'm a motorcyclist and we don't wait for critical parts to break to replace them, it leads to bad experiences. But like you I don't want to just unnecessarily throw money and parts at it either until problems or age dictate.

MK 82

Your O2 sensors are upstream of the cats.

imaruby

I got a '93 with the same hot starting symptom.Mine started after I removed the coolant hoses to the throttlebody. I just talked to Gordon Killabrew at Carlisle and he recommended I replace them.He seems to think its affects the heat sensors that control the fuel delivery.
Has anybody removed these hoses and had similar problems?

Thanks,Ray
keep waving

DWC4

I've seen a lot about doing this bypass to supposedly gain power, by keeping the inlet air cooler, did you gain anything? Interesting.

96GS#007

This is such People have been running this way for years, including mine for the last 13 years. At startup the ECM or PCM primarily looks at the coolant temp sensor, the MAP sensor, and the IAT sensor. During a hot restart none of these, especially on an LT1 car, are going to be affected by the fact the tb coolant hoses were removed.

imaruby

Have not made back to the track yet.Best so far was 12.7 @ 106.Plan to go back at the end of this month.Will get back with the results.
Ray

pcolt94

Interesting……I raised this same question in the same fashion about 2 years ago. Did not get any earth shattering answers. My car runs good also but when I got it in 03 it would start almost instantly as the engine turned over. Now it seems to crank for 5 or 6 seconds before it starts but does not happen every time. Sometimes it pops right off. But when it happens, it does not roar to a start. It starts slow, shakes a bit, stumbles as if it was to rich and it has to clear itself out. The exhaust also seems to smell rich but no smoke.

Do not see a direct relationship if it is hot or cold or if sitting over night. If I stop like to get gas, seems to start right up. It happens when it happens, no real pattern. Just came back from a week business trip and it popped right off.

I have been thru all the normal checks and not going to list them all as most have been discussed in the previous posts. I could find nothing really wrong.

With the 92-96 vintage engines, the ECM/PCM enriches the mixture for starting by adjusting the pulse width for the injectors using temperature sensors and such for input and determination. The one thing I have found is if I put the gas peddle to the floor, it starts more normal. This is because in the start configuration, the PCM leans the mixture by reducing the injector pulses. You would use this in the case of flooding.

My preliminary conclusion and current theory is I think the injectors might be leaking a bit causing a rich starting condition. Holding the pedal down lets my start with a leaner condition. My only other possible clue is that my fuel pressure only holds for 20-30 minutes after shutdown. From what I remember, after ½ hour its about or near 0. No visible leeks from FPR.

All in all the engine runs good and am just hesitant to replace injectors on a hunch for a slow starting problem. What do ya thing?

BrianCunningham

I've been running a TB bypass for 8 years now, no problems, even in the winter.

Did you check that?

FICINJECTORS

TELL YA WHAT, I BET YOU HAVE LEAKY INJECTORS, IF YOU WANT TO GIVE UP AN HOUR TO CHANGE THEM i WILL SEND YOU A SET, IF IT FIXES YOUR PROBLEM BUY THEM, IF NOT JUST RETURN THEM.
JON

Calderone

i predict another satisfied FIC customer !