I have been fighting my car for about the last year and have been unable to get it to run right. Suddenly though it has gone down hill though and yesterday I lost a drag race against my sisters stock 4 cylinder jetta.

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1990 Iroc
Canadian Iroc (305 TBI)
-14x3 open element, K&N
-Accel: Coil, Wires, Cap&Rotor
-B&M stage 2 shift Kit
- 4 255/50/ZR16 BFGoodrich Comp TA's
-Hypertech chip, low temp thermostat and fan switch
-1.6 ratio roller rockers
-3" exuast: High flow cat, meanstreak muffler, dual 2.5" outlets
-Holley projection Manifold
-670 Holley TBI.

 

Sorry, I accidently pushed enter.

Here's the problem, my car has no power, and it will not rev up. I can not decide if it is a fuel or igintion problem. When I floor it from a launch it jumps kind of hard but goes slower and slower untill it is not even accelerating!

My car currently will go faster at half throttle than wide open. Also it runs best when it is the coldest.

I do not believe that it is a problem with my holley TBI because it occured (although not nearly this bad) with my old TB.

What I have considered is:
-Fuel pump
-cat
-ignition
-computer and all related sensors

Are there any test I can do, or do you have any ideas. I'm considering switching to carb. I'm so fed up!!

Please help.
Thankyou,
Jordan

 

I'd suggest you look at your fuel pump first.

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92 Camaro RS, LO3, 5-spd, T-tops

Performance:
K&N Open Air Filter, Edelbrock performer TBI intake, Fastchip Prom, Timing +4 degrees, Centerforce clutch, Xact 8mm wires, SLP 1 3/4" Headers (coated), Flowmaster Catback Exhaust, Richmond 3:42 gears, Torsen HD Posi
Sights & Sounds:
Alpine 8030 Alarm System, Valentine One Radar Detector (How did I ever drive without one?), Pioneer DEH 7450 Head Unit w/6-pack CD changer, Pioneer DEQ 7600 Sound Processor, 2 Kenwood KAC-846 Amps powering 2 12" Pro Red subs, 2 Pioneer 6x9 and 2 MTX 4x6 speakers. Z28 grille w/aftermarket lights, MacEwen whiteface gauges
NEXT UP: TBI & Suspension mods

 

Fuel pump or CLOGGED fuel filter. Since the pump is in the gas tank. Replace that filter and see if there is an improvement.

 

I replaced the fuel filter about 1 year ago.

What is the best way to check your fuel pump? I have a gauge set up in the engine compartment, and have it set to about 11 psi (with Holley injectors that are too big). The one thing that has confussed me though is when I rev the engine I can see the pressure suddenly drop... Is this normal?

I was aslo begining to think it possibly has something to do with my spark advance...

 

A tbi car has this natural tendenacy to do this, but gets more pronounced with mods. I would check and/or replace the fuel pump. This is a hard problem to track down, and many people have fought this problem (although not as bad as yours) for a long time. You might need to look into a custom program to adjust a few things (pump shot, spark advance etc.) I think you should look into the fuel pump AND a custom prom. Also, check the basics like timing, rocker arm adjustment, etc. PLEASE post what you find, I think this is a very good subject and that the is a lot of learning potential here.


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1989 Lt. Blue RS 5-speed
355 crate motor, Compucam 2040,
PST Front suspension,
Hotchkis rear suspension,
EDL T.E.S., 3" Flowmaster
Harwood cowl hood

1994 Black Z28 6-speed
Nothing major, but FUN!

 

What I did not mention is that it is that my enigine will not rev up, and that is why my car slows. It will of course in neutral but not under load, and especially not under heavy throttle.

Thought you all might care to know:
-Yesterday I went to drive my care and found it had been broken into. Not only broken into but some one attempted to steal it.
When I came to my car I saw pieces of plastic all around it, and when I opened the door my dash had been all torn apart, and the stearing colum was torn open. The ignition was completely destroyed, and took me a long time to reconstuct. Although it looks terrible and the high beam and blinker are destroyed, I can start my car now.

They also stole my tools that were in the car, my stereo, my dad's cell phone, and my fire extinguisher.

Then I opened the hood, luckly nothing had been stolen, but for some unknow reason they decided to completely tear out all the wiring to my coil!!! This, as you can imagine, took me quite a while to jurry rig something to work.

AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!

I'm going to college, I don't have the money to fix this..... I called the police, and had a report taken but he straight up told me "There is basically a zero percent chance of us ever finding out who did this."

My poor car. I will no longer park it at school (I tried so hard to keep it safe here too, putting its cover on every night and parking it away from everyone.) my parents have a place a little ways away, and I will store it there.

Thanks,

Jordan

 

Sounds like too much backpressure and/or fuel starvation. Try freeing up some exhaust. I just had the same problem with my friends 85 T/A. Turns out the guy he bought it from put 305 everything on it. Just slid a 350 underneath it.

It had 305 injectors, 305 exhaust, 305 cam, etc. It wouldn't rev past 3000 rpm at WOT, and wouldn't move. So I pulled the tranny, had my other friend check it out at his shop. Put it back in, still did the same thing. So I just had him invest in headers, and new exhaust, it helped out a lot. It just sounds like your exhaust is clogged up, and your fuel delivery isn't what it should be like. You would be surprised.

-Todd-

 

Well the exhaust is pretty free flow, I got three inch pipe all the way back. Th cat I have is 1 year old and very high flow, but it is very possible that it has become clogged. The reason I'm not sure if that is the problem is because of how inconsistent the performance is.
Sometimes it will run pretty good and other times it will run terrible.

The one consistency it has it the car will always run better when it is cold.