Janaelen

O.K, After the numerous supercharger problems I've had, I finally resolved ALL of them. NOW another problem.

My car won't start, plain and simple. It would work fine but once in a while it would Die on me or seem like it was missing. I then put new connections on my Crane HI-6 and everything seemed well. I drove it around for a week and it seemed like it fixed the problem. But it came back. The car was having trouble staying on (like it was missing in a cylinder). Then I just parked the car for a few days, went back and the thing wouldn't start at all unless I had my foot on the gas ALL the way and then it would struggle to start.
When it did start I had to keep my foot on the peddle almost 3/4 way to get it just to stay on and it would idle at around 2000 Rpms(normally would be around 5k if I did this) and wouldn't climb but 100 RPMS if I floored it.
Shortly after, the car didn't want to start at all.

Now my so called "PROBLEM SOLVING" skills start to kick in.

I assumed it may have been clogged cats, so I pulled the complete exhaust off. I then try to start the car, No start.

Then I ASSUME it's the optispark (original optispark on a '92 lt-1 with 58k), so I replace it. NOPE! Not the problem (both before and after I was getting spark to the plug wires. I checked this by disconnecting a plug wire and putting in a spark plug and grounding out the ends. Shows a bright blue spark while cranking).

Then I start looking on the Net and start checking my oil pressure sensor, ect.. This was working fine the last time I checked so I really doubt this could be it.

I then check my injectors (with an Digital Volt meter) and the resistance on all is the same.

I THEN check fuel pressure and PSI is ~45-50

I THEN check both fuel pumps and all seems well.

I THEN checked the computer for codes (It had a MAF code). Even if the MAF was bad it wouldn't cause the car to miss (like 3-4 cylinders) would it?

I THEN thought about adjusting the timing, but kicked myself in the head because I wasn't thinking (Lt-1... Can't adjust timing. Thanks GM)

I also checked to see if the Opti was keyed right, and it was. I've been testing the starting with the waterpump off and the accessory belt off(ever since I pulled the opti, which was pretty much the last thing on my procedure list). I'm getting spark so I'm pretty sure everything is working right.

I'm thinking my ignition box may be at fault, but I'm not sure of how to test it. I know I get spark, and I'm pretty sure I'm getting fuel (fuel pressure and the distinct smell of gas when rotating the motor). Could a Faulty HI-6 ignition box throw the timing off Bad? Could it also cause a bad miss? Or am I, once again, not thinking straight.

Now, Let the posts and help begin. I may not be the brightest star in the sky, but I have surprised myself before.


P.S.

I'm in Austin , Tx so if someone wants to shoot me, please do. :):smash:

Janaelen

Oh yeah.. Almost forgot. Some of you may be thinking, Why doesn't he take it to a shop. Well there is a simple answer to that....

YOU CAN'T Trust ANY SHOP IN AUSTIN! Words to live by!

Plus the satisfaction from repairing something this irritating is a reward all on its own.

88L98

if you are having to floor it to start it, its going into clear flood mode. you might be having problems with leaking injectors.

Corvette ED

Did you pull the spark plugs to see if they were fouled out?

96VegasVette

:yesnod:
Fouled out/soaked with fuel.

Janaelen

corvette ed, 96vegas vette

I pulled a few (not all) and they were black(because the car runs rich) but all seemed to fire whenever I tested them. I also checked them right after I tried to start it to see if they were soaked with fuel, and it didn't seem that way.

Thanks for the advice

Janaelen

That was one of the other things I ASSUMED (Man I need to quit doing that) but the injectors only have 1200 miles on them. Unless Accell has a bad rap about failing injectors ( if they did fail, I can tell you it was more than just one).

Another "DUMB" questions. My FMU kicks fuel pressure up to 80-90 PSI whenever it reads boost, do you think this could cause premature injector failure? I recently(within the past 200 miles) found that the FMU vacuum line was cut and in bad shape(probably not raising fuel pressure due to leak) so I replaced the hose.

Thanks again

88L98

>>>That was one of the other things I ASSUMED (Man I need to quit doing that) but the injectors only have 1200 miles on them. Unless Accell has a bad rap about failing injectors ( if they did fail, I can tell you it was more than just one).

someone on here had an accel injector stick in the "open" position within an hour of installing the new injectors. it flooded the crap out of his engine.


>>>My FMU kicks fuel pressure up to 80-90 PSI whenever it reads boost, do you think this could cause premature injector failure?

i would definately think so, maybe you need to go to higher # injectors and change the injector constant in the computer and have the FMU only increase the fuel pressure a little more, not quite to 80-90psi

Janaelen

Any idea on how I can check these injectors? Or should I pull all and just send them off?

I don't really need the FMU, I just have it there because it was there before. I had a chip burned through Exotic Muscle and it's supposed to handle the fuel maps accordingly. I guess I'll disable the FMU and find some way to test the injectors.


BTW, the fuel injectors are 36#.

Thanks for the info

AquaMetallic94LT1

I can tell you how to check the injectors. They need 5.5 volts to operate. Get four D cells and a battery holder for them. Solder two wires on it. The negative terminal wire should go to the left terminal and the positive should go to the right terminal. Check them with injector cleaner. The liquid should flow through them. Take the whole injector rail off of the intake and disconnect the fuel lines. Let all the fuel drain out of the rails. Then pour the injector cleaner into the fuel rails and energize each injector. The fluid should come out.

A couple thoughts come to mind. Check the condition of the wiring for the boost based retard control. The ignition system might be pulling all the advance out. Make sure you are getting good fuel pressure when the car is started and running.

Janaelen

AquaMetallic94LT1,

Thanks for the suggestions, I'll try that later tonight. As far as the ignition system, it's not a BTM or it's not a timing retard unit. All the timing is pulled from the custom chip. It's just a regular HI-6 Ignition box (comparable to the MSD-6AL). If these go out, do they normally throw timing off?

And once again, thanks for all the replies.

88L98

i dont think your timing would play a factor in the no start condition if it started before and just wouldnt start out of the blue, unless your timing got way advanced for some strange reason. i would take that FMU off and just use the chip to add the needed fuel under WOT. that could very well be what is messing up your injectors. a friend of mine had 3 bad injectors on his car and it wouldnt start period, no firing or anything. try taking the connectors on the injectors off, and place an ohm meter across the two contacts on the injector, you should get a reading of 14-16 ohms cold. if you have any below 12 when cold, they are starting to break down. if any are at 10 or less, they have pretty much broke down already and are shot. when the injectors are hot, the resistance will ususally go down 2-3 ohms.

Janaelen

Well, I checked the injectors and all checked out between 16-18 ohms. I'm thinking they're either leaking or I locked something up. If it only takes 3 to lock up and prevent the car from starting, then I'm pretty sure that's the case.

I'll pull them all and test them. Heck, I think the car needs to get lowered so I might just send them to accell to get check/cleaned and calibrated.

Anyone think it might be something else?

Thanks again for all the replies.

Chris@SD

This is the first thing that I would check!!! I got a strong feeling this is your problem. If you have a buddy with a MAF car, swap them out real quick and see what happens.
Anyway, that is my vote.
Good Luck,
PS I can't remember all you had, but I do not think that 36# injectors will do for your setup. I am thinking 42# injectors will evne be in the edge. You might try it though.
Again, good luck!

Janaelen

I meant to say MAP sensor code (but I guess if either were out it would do the same). It's a '92.

I had some people do some equations (as well as ATI) and for 560rwhp I was told that it came out lower than 36#. I originally had 48's but returned them because people were telling me that they were an overkill. I'm adjusting the FMU to kick the pressure up to 60PSI or so whenever the boost kicks in so I'm pretty sure the fuel would be ok.

P.S. at 6PSI and WOT the car would throw black smoke out and the A/F read rich.

Thanks for all the info so far. I've got some time to tear into the car again tommorow so I'll try testing the injectors and runs some tests on the MAP ( I think that's possible, right?) and see what comes up. If I can at least get the car started, I'll probably purchase a DIACOMM PLUS setup and start data logging what's going on with the car. This guessing game is getting old REAL quick.

AquaMetallic94LT1

Check the engine coolant temp sensor connections and the temp reading on the dash. I fogot to connect mine and the car would barely start or run.

SpedRacr93

Just unbolt the entire fuel rail as a system (without disconecting it) and put all the injectors out of the manifold. Then place some good clean paper towels under all of the injectors. Turn the ignition on. When the fuel system primes, a leaking injector will "spooge" on your paper towel.

Check IAC and TPS on throttle body as well. Those are some simple electronics that can go bad and sometimes cause what you're describing.

The ignition box can be bad also. I've lost 2 MSD boxes and they did the same thing that you're describing happened to you, except they were on a midyear.


[Modified by White Lightning 89, 11:19 PM 10/16/2001]

Janaelen

I just thought I'd follow up on this thread. I finally figured out what the problem was.

After pulling the OPTISPARK and messing around for a while, I deduced that my ignition system wasn't at at fault so I pulled my injectors to send of (because this was the only thing I could think that would be the problem).

Well, turns out, I was right. I luckily had a friend with some spare injectors that I tried on my car. After a few turns, it fired up and acted decent (I don't have the exhaust on the car now because I assumed the cats were clogged but they weren't). I'm going to install the exhaust tonight and start the car and take it for a spin. (MAN, I hate having to replace the optispark. ESPECIALLY when it wasn't at fault!).

Anyway.... For anyone reading, I purchased accel 36lb/hr injectors for my car and apparently 80PSI of fuel pressure was too much so I'm getting these repaired through warranty and will disable the FMU(probably just pull the vacuum line). Once again, thanks too all the forum members that gave advise!


I can't wait to get the car back on the streets this weekend!