chevykevv

Before you call me retard or flame me please read on.

I have an 89 vette L98, beautiful car even won best early C4 @ our Nationals.

Problem is it's so Bl##dy unreliable, always throwing up a check engine light on nearly every journey, & never the same fault, I don't want to sell the car but i'm getting frustrated.

Options are as I see them:
1: buy a complete set of sensors & replace the lot.
2: convert to LT1 top end, but would this be more reliable?
3: Carburettor, going backward but if it has gas & a spark it's basically going to run.

We don't have such strict emmision laws here for cars before 1992, so I could even strip the CATS off it if I was that way inclined.

Question is has anybody gone down this road (for race use?) if so what do I need to strip down to before the rebuild?

What combination do you recommend, i.e. Edlebrock, Holley etc?

Any help would be greatful as I don't even like going on short journeys at the moment, just in case.

Happydad

Hang on to your handlebars...Here we go........

rodj

"convert to LT1 top end, but would this be more reliable?"
LT1 top end won't fit easily on L98 block

You need a regulator to drop fuel pressure down to carb requirements , a low rise intake so as to clear Vette hood and a regular (non computer controlled) dist. Vac sec carb;650-750
Remove intake and replace with carb intake.
Obviously there is some reworking required in the wiring.

The majority of the posts you will get will recommend you do some fault finding as to determine what your problem / problems are with current setup..

"never the same fault"
As in ?
Faults always in same system;fuel/ electrics/etc.

adi4

Hi Kev

What are your common fault codes that you are getting?
give me a ring if you want 07831 812120.

If you were thinking of converting to a LT1 manifold I am converting some at the min as a bolt on option for the L98, and still using the standard dizzy,

chevykevv

Hi had fault light come on 4 times on the way home from the NEC, it was dark so not had time to track codes, So far this last two months i've replaced oxygen sensor, idle control valve, then I had "MPS" manifold pressure sensor, the car runs way too rich when cold, & probably too rich when hot, I was going to see if the previous owner had it "Chipped" but now it's dark every evening when I get home.

Contacting Tom Newman to see if he can do a diagnosis.
I just want to drive the car, as you can see from this photo, it attracts attention, this was at the classic car show at the weekend.

brian84

awesome looking vette.

I say go for the carb. your bigest issue will be keeping the factory dash functioning. I think you might loose some features like the mpg read out, but I dont think its all that bad.

I had concidered swaping to a carb on my crossfire, but decided to keep the turd and try and polish it a bit. looking back on it, I should of just swaped out to a carb. I never liked electronics much.

Sam Lam

chevykevv: I have a 89 Corvette too and it has had problems. I was challenged by each issue, read materials, posted on the forum, learned a lot and was then able to repair my car ........ myself!

This forum was designed to help people who are having problems and want to learn more about their car. If you want suggestions ..... other than go to the old technology of carb gas input, here they are:

1. The injectors on 89 - 91 have a high failure rate. Injector failure can cause many problems that do not point to injectors. Check your injectors as this is easy and does not cost you any $$$ or European currency. Spec is 16.5 +/- .3 ohms when cold. Good injectors will have higher resistance when heated and all will have approx same resistance value. Bad injectors will have low resistance values when cold and will either go up, go down or stay the same when heated.
2. Invest some money into a scan tool to fully understand what is happening with the engine sensors and controls. It is amazing what you will learn here. I like the Turbo-Link system and it costs $279 USD. Here is the URL to its web page: http://www.turbo-link.com/
This software has a demo that you can download and it is amazing on what this system can do for you. It has the ability to graph any three sensors or parameters on the same timeline for trouble shooting.
3. Invest into a couple of books on fuel injection and learn what is going on while you are driving the car. This is a vacation in itself!

Consider the $$$ you are going to spend on the carb system and what you are doing to the value of your car by going to a carb system.

If you need more info on any of the above, just PM or email me.

Bob

RacerX70CC

There's a car in that photo?

Demonic85

I would love to switch to carb cause its so much more reliable. I'm having problems left and right like you too. It would be nice if someone wrote a guide on how to swap in a carb in place of the TPI. I can put the engine together, but the wiring, plumbing, etc. would worry me.

93-383

Ive been considering a similar switch for my Lt1. As for you questions swithing the sensors and associated wiring may help although without knowing the problem you will often just be shooting in the dark. I also recomend checking the resistance of your injectors as stated above.

Right now I am still in the planning phase of my swap and am looking over the ECU wirinig diagrams to try and figure out how to keep some of the functions of it without droping the whole thing. There are a lot of functions to either figure out a way to modify to still work or outright replace with other hardware.

Last recomendation check the ECUs ground conections if they are not good you can have a whole host of problems that are a pain in the rear to find.

rick lambert

If your car is attracting that kind of attention I'd be happy to tow it to car shows for you .

Actually, if you're headed in the carb direction, check the archives, been alot of write ups stating exactly what they used and did.

jhammons01

Holy bajeezus

where is CFI??

93-383

Archives? when I used the search function last month all I could find where threads bashing people for even thinking about it.

davenbocafl

I just converted my 86 to holley and edlebrock intake, it was necessary to clip the check engine wire and really after the conversion it was of no use anyway, the engine runs smooth as silk

BTTB

www.thirdgen.org (technical articles )

AZC4Guy

Let me know if you decide to do it, I can help you with wiring/plumbing.

AZC4Guy

Kevv, it's not all that difficult of a process but you will be reducing resale value if you convert to carb. I built a forged 383 then put a carb on it for my '86. No regrets. If you decide to do it, you can contact me any time.

Be confident on the emission laws you mentioned.I do not have to pass emissions down here in AZ because it is listed as a collector's car. In a couple of years I'm moving to Northern Wisconsin... no emission laws, wheeeee!


Steve

Erod579

azc4guy

I would love to see pictures of your engine compartment and your hood for clearance purposes.

mseven

I think you can make it work w/either. My vote is to learn and spend the time to get the efi/ecm system working the in way it was intended.
BTW, nice hood ornament.

chevykevv

I think I get the message, persevere with what i've got, I'll get the car scanned & then get in touch with adi4 to tweek things a bit, thanks for your honest advice,

More pictures to follow if you lot are interested in number plate surrounds ?????
just awaiting photographer to put them on his website.