ok, this car still has cold start problems, and is pissing me of very much!! Heres what I've done, PLEASE help me. I'm getting very tired of trying to fix this damn thing.

1. swapped coils
2. ICM replaced
3. New A-1 Distrib.
4. BRAND NEW Master pro Cap/rotor
5.. Wires are around 3mo old
6. Swapped plugs
7. Fixed wires to coil.

Fuel, tested 3 times, get between 40-44 psi every time
8. New pump, v8
9. Filter is around 5mo old
10. Swapped regulators
11. Went to 17lb injectors, went back to stocks
12. Took that little "ball" out of the line buy front of intake

Air
13. Installed TPI intake with new filters

Other crap
14. New ECM with prom chip
15. New IAC
16. New Battery
17. New Alt
18. New Belt
19. New Belt tensioner
20. Checked vacume, fine
21. New T-stat
22. Swapped ECT
23. Gutted Cat
24. Swapped Starters, still probs, rebuilt stock, put back in.
25. repaired wires to starter, had green crap on them.
26. New battery cables, + and -
27. New EGR
28. Disabled SRS while doing all this


Ok, TPS is STILL acting up, I put a fully adjustable on it, stumbled while driving, but no CEL. Put one back in that throws cell, but no stumble.

Will a TPS cause hard start issuse.

What else am I missing??

 

TPS might cause a hard start condition if it puts the computer into "clear flood" mode.

I really don't have any suggestions other than to check the condition of your bulkhead connector. After that, it may be time for the pros to look at it (spend money, save sanity).

 

Now it dies while coasting. Just shoot me!!!!!!!!!!!!!!

 

sounds like that bulkhead connection to me...

 

Just going over the list... how's the timing? Did the outer ring of the balancer slip, and you think it's timed at 10 advance, but it's really not?

How's the ground strap at the rear of the driver's side head?

How's the MAP sensor doing?

Is EGR sticking open? I know, it's new, but did you try bypassing it at the TB with a block-off plate?

How's the fuel pump relay? Altho, if the relay was dying, it would just take forever to crank- until enough oil pressure built up to turn on the oil pressure safety switch, which bypasses the relay, and sends +12 right to the fuel pump.

Did you try any wiggle tests on the wires? As in, engine running, clothing/hair/jewlery/small animals away from the fan belts, try wiggling wires. Maybe you've got an intermittant somewhere.

Could you have a short on the TPS wires? Like MD said, maybe you're going into clear flood mode b/c a wire is shorting out. You have the GM book, right? Did you go over the charts?

 

I replaced the distrib saturday, it ran great sunday. Now it acts up today where I can't work on it for another two weeks.

I am going to look into true acdelco tps (as said on gen tech board while back.)

Timing was set around 11-12 degeres

***, now you got me thinking I didnt put map plug back on, or knock sensor plug.


Fuel pump relay, hum, is that a reg relay, I got one of them off l32 wire harness if so

No, don't have GM book

 

what's the fuel pressure while cranking?

Also, what's the oil pressure before the car stalls while coasting? (not like you're looking at it at that exact moment )

 

Well oil pressure gauge is broke in the car, It stalled several times today. Took 3 cranks to fire.

3 x's it died fully. About 4 or 5 other times the RPM gauge would drop to 0 then shot up pretty high it would drive fine for a few then do it again.

Also while driving in town it started "bucking"/jerking pretty bad. Almost like the fuel was messing up. Felt like I was trying to drive a standard and didnt know what I was doing. Also when it was jerking I could kinda smell gas.


B] B]Could the TPS cause ALL of this??? Including the hard to start when cold????[/B]

 

check metal fuel ines for pin hole leaks. I had to repair both of the ones in the engine compartment. Also, a bad oil sender could mess w/the voltage going to the fuel pump.

 

wouldn't a leak though also affect my gas usage??

Also forgot to mention every time it died, it would start right back up as though nothing was wrong.

 

Think I am going to re-check my work, get a new throttle body (snapped screw of in it) and new tps.

Re-check vacume and fuel pressure.

 

Can you rig gauge to read fuel pressure while driving around?

 

That TPS thing makes it real funny, i would almost think you should do some testing of the wires from the TPS to the computer, you need a test light with a long lead and a friend. next thought would be the computer, maybe it got real hot too many times.

see if a junk yard will let you test another computer for a small fee.

 

Gumby, thanks for thoughts on wires. If new ACdelco wont "fixit" that will be next issues

As for computer, I have gotten new computer and still does same thing. It even came from same year, same model (1991 Camaro, not a 92 Bird Etc).

Rig up fuel guage, hum Maybe paint new hood, pull old hood off, drive for few days w/o hood and rig one up. Then install new hood.

Got question on fuel, should my pressure drop to 0 over night??

The pump sometimes runs for a while after car is turned off, how long do you guys' pump stay running after car is turned off? Or does it?

 

Ooo man, I'm such a stupid ***

I'm just now figuring out why you guys keep asking about the oil pressure. I was like WTF are they asking about oil pressure, but I think I got it.....


If it doesn't see enough oil pressure at guage, it will quit sending a signal to fuel pump to enguage it. So since its colder, oil wouldn't be building enough pressure to trip that little trigger.

Correct ?? Its a safety feature to keep from blowing engine up?

Wonder if my 3.4l has this system, if so, I'm screwed. Time for re-wiring.

Will get opsu today, I got my tax refund check in yesterday

Any specail tools to install it?
Going to get delco tps from dealer at lunch also.

 

3.4 harness I had, probobly you too, only had that 1 huge connector to it. from what i've read on Firebird/CamaroV6 all the 4th gen birds had this too.

and you're right about the signal to the fuel pump based on the "erl" pressure

 

I got a good way to rig up a fuel pressure gauge. I had to do it to my sc when it was having problems. I got a mechanical gauge with a long hose that could screw onto the shrader valve on the fuel rail, the gauge also had another hose that was used to bleed off the pressure once you pressed a button on the gauge. I ran it up through my cowl inbetween it and the cowl weatherstrip on the hood and duct taped the gauge down on my hood.

 

Alright I'll bite!
I only know of pressure reading while vehicle is stationary.
What did yours show while driving around?

 

I think it was 40ish psi but I really cant remember it was soo long ago when I did that.

 

It was constant, didn't vary up or down?
Impressive system.

 

Well, uh, "half" right. If the sensor (not the gauge!) doesn't see enough oil pressure, it will quit sending a signal to the fuel pump to engage it.

However, this oil pressure switch DOES NOT PROVIDE A SAFETY FEATURE!!! The "bold" is because everybody thinks this, and argues about it, when it's clear as day in the GM book. (Goes back to a heated discussion a long time ago on the tech boards.)

The oil pressure switch, when it sees enough oil pressure, will bypass the fuel pump relay. Power goes right to the fuel pump WITHOUT going through a relay first.

So, the relay can die while you're driving, and your fuel pump will still run (from the oil pressure switch).

Or, the oil pressure can drop to zero while you're driving, and the fuel pump will still run (from the relay).

A dead relay usually causes long cranking time, because you have to build up fuel pressure to bypass the relay.

Now, say you have a dead relay, AND a bad oil pressure sensor. You're screwed... voltage won't be getting to the pump.

And what MDv6Man said a while ago applies too. The "bulkhead connector", the positive junction block, supplies power to both the fuel pump and the ECM. I had that ring terminal go bad on me a few blocks from my mechanic. Had it towed over there; after 3 days, he told me my fuel pump relay was getting no voltage, his diagnostic computer was telling him "no computer", and he said "either I can trace the wires, or if you want, you can do it." So I had him hotwire the fuel pump relay and I went home... 20 minutes later (after going after my starter kill, oops), I found the bad ring terminal.

 

Ok, parts place says the sensor and the switch are in same part. Have one of them, will be putting in tonight.
But this sensor/switch could make car die while running, and hard starts corrrct?

I will check that hotblock.

Also have acdelco tps I'm gonna try.

I put some gas dry in the tank.

Anything else needed??

 

Yeah....

Get a new fuel pump relay. On the 2.8s its on the drivers side firewall. I had a bad one on my 85 and stopped quick at a light. Car shut off and would not restart.

Quick test if the 3.1 is the same as 2.8s-- The blower motor relay is located next to it and is the same size/type. Switch 'em. If the car runs better, replace the relay

 

Ok, I got one off my 3.4l harness, its the fuel pump relay for it. Hopefully its same, just different color.

Tis on the firewall, driver side, right around break booster area, has 3 on a little "bracket" or similer nature.

 

Yep.

 

exactly which one is it?? Middle, drivers, or pass relay so I swap the correct one?

 

I think it's one the front of the bracket closest to the fender. I know its not mounted on the back (that is an AC relay).

 

Do you have a cold start injector? If so did you check it? If that 's good, bump your timing up, don't go by 12* keep moving it up and see happens, it's either going to run worse or better.

 

No C.S.I.

Timing is already at 12*

 

That's what I mean, don't go by the 12* that you see. Bump it up to 14, 16, 18, see how it starts and runs. Your mark can be off. Move it and drive it thats your best test.

 

Now computer cars are a tad different and I havnt done it too my bird but on everything else. I only use the timing light or marks as a refernce, I then tune it the rest of the way by ear and feel.

Most old tuner do it that way, and the real crazy ones go one step further. you find a stone parking lot and while one person power brakes it in the stones, another sits under the hood adjusting the timing. That ones take a bit of trust on both parts.

I set my timing on the mark, then I hold the gas about half way open and then adjust it till the rpm's just smooth out, and then make sure it rev's up fast and hi quick, and then a drive and mye a tweak or two on the side of the road. it really an art once you get the hang of it. but with cam chaine strech and a million other variables once you have tuned enough engines, them marks are only a refernce point.
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And Dale if you do not have enough oil pressure and your pump relay is shot it will die on you. But I would be real conserned about that, you may have a shot oil pump or really really low on oil pressure. It only takes 7?psi of oil to prime the pump.

It may be a much bigger problem than stalling.

yes it will take 2-3 tries to start when cold as it need to build presure but if its dying once warm ad moving, you would have to have super low pressure for it too stall out.

 

I've had my old bonnie tuned liek that. I was on the brake & gas in the dudes garage, he was underneath the hood advancing it until he heard audible knock, then retarded it a couple degrees.

I do agree, do this w/only people you trust, or will give you something to talk about a few years from now

 

Knowing my luck id get ran over. lol

 

you may have a coolant temp sensor that has high resistance at the ECM. maybe just a bad connection. yes the TPS can cause it as well. I get tech info from Mitchell's manuals at the local library. Is this a 3.1? I am assuming it is. The map may cause rough idle but I doubt cold start problems. You can unplug it and the ECM will assign a default value to it. does it have the digital EGR with the three solenoids?

good luck,

Don