Morningwood

Ok so quick rundown. 88 GTA with tpi 350. All ignition parts have been replaced, new fuel injectors, pump, new top end gaskets, new plugs, wires and coil. The car only starts when you floor it. And when it does start it ships and pops bad. Checked everything I know 10 + times. Wire placement is correct and plug gap is correct at .35. I'm at a loss here and almost ready to give up on this damn thing. I really don't know what it could be. Timing maybe buy all marks lined back up from top end gasket install. Any help would be appreciated. I was also wondering if the timing chain may have skipped or something. Idk if that's a thing or not with a small block. Anyway thanks in advance.

zed-028

clogged cat?

tealman92

Did you replace the fuel pressure regulator? What's the fuel pressure at?

tealman92

You replaced the entire distributor with a new one?

Morningwood

New fp regulator, new cap, rotor, and button.

Morningwood

Have not checked fuel pressure yet. Can't find my guage. I do know every part on the fuel rails is brand new and has never seen a mile on the road.

Morningwood

Also no cat either.

Vader

When you test fuel pressure, monitor how long it takes for fuel pressure to drop off after the pump stops. That could be an important clue as well.

Along with that pressure information, it might also help to know what type those new injectors are.

Presumably the distributor was installed in the same position as before, but does that include the rotor position? Timing would still need to be set with a light. You might want to remove the plugs and crank it to set base timing. See if the new plugs are wet when you do that.

Morningwood

Yes sir. Cap and rotor are in same psition as marked. The injectors are remanufactured Bosch units which are supposed to be drop in for 350 tpi Camaro, Trans am, and Corvettes. 4 hole design 22lb. I wanted to set timing but the car won't stay running that long. Also I have brand-new plugs in it that have not seen the road. Pulled last night for another new set.

Morningwood

The ( old) plugs that are new were wet. That's why I replace them. I thought they may be fouled.

GeneralDisorder

iTrader: (1)

Let's back up for a minute.

1. Did the car run, and if so how well, before you started the top end gasket replacement, etc?

2. Have you checked static ignition timing? Set the engine to TDC on #1 compression stroke, back it off to the desired BTDC timing, and then check rotor position? You can drill a hole in the old distributor cap below the #1 plug tower to help with rotor alignment inspection.

GD

Morningwood

Doing so as we speak. I did not drill a hole in the cap. It was running decent when first fired up from top end gasket swap. Turned the car off and then all this happened.

GeneralDisorder

iTrader: (1)

Was any of the work done *after* it ran decent that first time you fired it?

GD

tealman92

Ok you only replace cap and rotor on distributor. Sounds like you need to replace the spark control module inside the distributor.

Morningwood

No spark control module has not been replaced. It is black smoking when I do get it to run tho. I've checked literally everything lol. I'm so done with this thing hahaha. I'm not sure where to look. I haven't tested the fuel pressure but due to the black smoke I'm thinking it has good fuel pressure.

Morningwood

Do you mean ignition control module in distributor or spark control module on firewall?

zed-028

could this thing be 180 degrees out of timing?

tealman92

The module in the distributor

Morningwood

I've checked timing today and everything is in check with that. I was under the impression that when the ICM went out it just went all the way out and the car wouldn't start at all.

tealman92

Nope. It will fire then die or run ok then crap out. I have seen them do some weird stuff. I would replace it. Make sure when you install the new one you apply the grease to the bottom of it

GeneralDisorder

iTrader: (1)

Black smoke sounds like too much fuel. Can you watch live data for coolant temp? If not you should check that it's connected and check the resistance against the actual coolant temp. Also watch fuel pressure and make sure it's not bleeding off through an open injector, etc.

GD

Morningwood

I've replaced the injectors with new ones when I did the top end gasket set. I mean brand new injectors to. I will look at the coolant temp switch later but I'm not to sure that would cause this to happen. Run rich due to coolant switch absolutely but not this rich. I mean like it will black smoke pretty bad and burn your eyes out lol. I'm going to replace the ICM tomorrow and let y'all know what happens. Also I can't get the codes to read when jumping the connections on the diagnostic port. Any direction on if the distributor needs to be grounded or any ground I may have over looked the first time?

zed-028

dist is grounded through the block however the EST circuit is grounded on the back of the passenger side head - its a horrendous thing to get at

Morningwood

EST?

OrangeBird

iTrader: (1)

As one point of info to try to help your diagnosis , with our cars when you floor the gas pedal while cranking the engine , you are actually shutting off the injectors since a floored pedal while not running is "Clear Flood Mode" . So , Your flooring the pedal causing it to start is telling you that something is dumping mad fuel into the engine , be that the injectors or regulator . Yes I know you said you replaced them but don't ever make the false assumption that brand new parts can't fail , yes indeed they all to often do and something is causing the excess fuel . Don't also forget , our injectors are opened by an electrical signal from the ECM , but they are closed by fuel pressure , and so a low pressure condition caused by a possibly faulty new pump or fuel filter is a very real possibility here .

In order you need ;

#1 ; a proper fuel pressure test ,

And ,

#2 ; a "Noid light" test of the injector pulse ,

And then to report back here with the results of those two tests .......

Morningwood

10-4 it may be a couple days due to me having to go get a noid light. Also as you said about the fuel pressure. A low pressure condition could cause the injectors to stay open due to the injectors being forced closed by the actual fuel pressure? Also injector pulse is provided by the ecm. I checked the injection wiring with a multi meter and have voltage on all injector plugs. Thanks to everyone for the info and help. Really appreciate it. Just trying to get all the info straight.

zed-028

EST is electronic spark timing circuit. from memory its either a brown or a white and black wire running on a ring connector to a bolt on the back of the passenger side head

Morningwood

Appreciate it. Thank you

GeneralDisorder

iTrader: (1)

Don't assume that brand new parts are not defective, or couldn't have been stuck open with debris from installation, etc. Don't rule them out because they came in a new box and were rubber stamped by a chinaman.

GD

OrangeBird

iTrader: (1)

I believe the "don't assume brand new = perfectly serviceable" advice has already been given once in the thread , and without the derogatory slap aimed at folks from China . Remember this , Mr. GD ; The Chinese will build to any quality/pricepoint we Americans are willing to pay , and it would appear we are all too happy with our cheap (both price AND quality) goods and are not willing to pay a bit more for quality . You likely aren't old enough to remember when "Made in Japan" was a synonym for "Junk" but then a funny thing happened , especially with their electronics and automobiles ; WE decided we wanted a better product , decided it was worth a bit more money to get a better product , and lo and behold the Japanese cars and electronics are some of the most sought after by a goodly number of the general population today .

So , the problem isn't the evil "Chinaman" , you really wanna see why our products suck ? Look in both your wallet and at a mirror , and the source of the "problem" will become plainly obvious .

PS , as an American of Irish decent , I have no skin in the game as per China , I'm just sick & tired of the Chinese people taking the rap for us American's all too eager willingness to buy our trinkets with the rock bottom price being the only purchasing decision criteria ..............

GeneralDisorder

iTrader: (1)

Well I've worked in Japan, and Taiwan, and China, and I can say that the cultural differences are staggering. Japanese and Taiwanese people are more concerned about job quality in general. In Japan and Taiwan they actually want things fixed whereas in China they just want you to pay them to say it was fixed

And yes "American" manufacturers via consumer pressure for lower prices are mostly to blame for seeking out this level of incompetence to do the work in the first place.

It doesn't change the fact that I, as a shop owner, have had to eat the labor cost of installing these garbage parts on many occasions because the "right" parts weren't economically viable for my customer. And that's part of moving up through the ranks of economic stratification with regard to customers. I spent years catering to people that were looking for a better deal in the interest of building a reputation for quality and excellence. Now I'm not so constrained and when I tell people that I won't install the $100 Chinese part and that they have to buy the $400 dealer part they usually go with my recommendation. But it took almost a decade to drag my customer base up to that level.

I just wanted the OP to be aware that we get a lot of dud parts and also that it could have been damaged during installation (or shipping for that matter) and not to assume anything.

GD

Morningwood

Thanks everyone for the replies and comment. As for the injectors I bought the from a company that sells new and refurbished Bosch injectors. The quality looks to be too notch and I did not damage any injectors upon installation. I understand the concern of faulty parts and cheep parts. I am one who tries to buy good quality parts for this car and the several other I have. I tested the injectors also for correct resistance. All checked within spec. I'm going in the next hour to get the fittings to put a fuel pressure guage on the rail and get noid light. I'll keep you updated when I get back. Thanks again

AlkyIROC

If in doubt, put the old injectors back in and see if it will run.

ploegi

Verify that the temp sensor for the PCM is plugged in, and working properly.

GeneralDisorder

iTrader: (1)

Also don't discount the possibility of a cracked ECM circuit board. My 86 TA died in that manner gave similar symptoms. Try to talk to it.

GD

Morningwood

Ok people. I have tested the injectors with the noid lights and have injector pulse. I also dropped a new distributor in. Car fired right up. Was monitoring fuel pressure and it was at 42 psi. Car ran for around a minute and cut off. While cycling the key the fuel pressure would jump to 42psi and start to fall. As soon as I started the car back up it would go to 42psi and the bounce around vary rapidly from 42 to like 30psi while running. Then after about a minute it would shut off. I'm not to sure if it's the fuel pump dying off or a electrical issue with spark or vats. Any help is appreciated.

GeneralDisorder

iTrader: (1)

Try bypassing the fuel pump relay for starters. That's easy to do and you may have a relay with a weak coil, etc.

If it still shuts down on you then I would be seriously looking to try a known good ECM. They are actually really cheap - like $85 from Napa for a reman 7165 ECM for your car.

GD

Morningwood

Any tips or information on bypassing the relay?

GeneralDisorder

iTrader: (1)

The fuel pump relay should be the center relay on the firewall behind the drivers side strut tower. Disconnect the connector and install a jumper wire between the terminals with the two fattest (large diameter) wires. These will be the pins for the fuel pump power supply and load and should immediately power on the pump if you have the ignition turned on. If you don't see the fuel pressure rise and hear the pump come on then you may have the wrong relay - sometimes they get mixed up and moved around or the connectors can get mixed up as well. Here's the connector with the correct wire colors:

http://www.hawksmotorsports.com/fuel...tpi-88-89-tbi/

GD

Morningwood

Ok so I jumped the fuel pump relay. Fuel pump was on and I could plainly hear it. Put about 8 gallons in the tank so I know it's picking up fuel. It will fire right up run great for a few moments and the idle gets lower and lower till it just shuts off. I started it and observed the fuel pressure guage. It is at 42psi with the key on. Both with the relay and with it jumped. As soon as the engine turns over the fuel pressure guage goes to around 30psi and stays there with rapid fluctuation between 30-38psi. After the engine dies out the pressure drops off. Upon trying to start the car again it just cranks and fuel pressure fluctuates from 20-35psi with a no start condition. Not sure which way to go with this.

tealman92

Your fuel pressure shouldn't drop off. When the engine is shut off your fuel pressure should still hold. Couple of things could be wrong here. Fuel pump back bleading, the fuel pump starting to fail, fuel pressure bleading out between the fuel pump and hard line in the tank. The fuel pressure regulator starting to fail or torn diaphragm.

Morningwood

The regulator is brand new account Delco. I'm starting to suspect a failing fuel pump. But I'm not sure. What would cause a pump to back bleed? Also before I bought the car I was told I got a new fuel pump a year prior to me buying it. Not saying it is working correctly but damn lol. I have check all the fuel line I could see from tank to rail for maybe a leak or pinch and everything checks out.

zed-028

did you change out the pain in the **** fuel filter underneath the car?

Morningwood

Indeed brand new one as of before I turned the key yesterday. Checked for leaks after installation also. I just tried starting the car. Fired right up ran for 30sec at 30psi and died. Tried starting again and nothing just cranking. Upon switching key to on position relay clicks fuel guage reads 42psi. Crank the car the pressure gauge drops to 20 and rapidly fluctuates from 20 to 38psi. Jumped the relay and same thing happens.
When relay is hooked up it kicks the fuel pump on, primes to 42psi. Relay kicks off and pressure drops off.

GeneralDisorder

iTrader: (1)

It certainly sounds like the fuel pump is unable to meet the engine's fuel demand.

Fuel pumps are cheap. And crappy ones are VERY cheap. And you do get what you pay for. A VERY good pump will run you about $110.

Could be they used a cheap junk pump. Certainly wouldn't be the first one I've seen.... this year.

Buy a pump. Submerge it in a gas can, run a fuel line into the rail and connect it to a battery or jump pack. If it solves the problem you know what needs to be done.

GD

zed-028

yeah sadly it sounds as though the pump could be on her way out...

many dont condone it... but i cut a hole - entirely your choice

Morningwood

Unfortunately that decision was already made for me...... In the most ugly way possible.

zed-028

you will thank these horrible people for their final act of ugly kindness

Pro

So, you are turning the key to start the engine, and the pressure is flickering 20-38, and not starting up... And when you dont turn the key, and just turn on the pump manually via the relay jump, you get a constant pressure, with no flicker?

That 20psi is enough to start up. I currently have a weak pump that Ill be swapping soon, and it starts up fine on 20. Maybe you have an ignition issue instead. Check your oil sensor. Maybe that thing is flaky.

Morningwood

Ok I'll check that. What does the oil pressure do to spark?