Ok heres my story:
My 1988 vette would just die on me until the car sat awhile..or i would disconnect then connect the battery up then it would start immediately:
Took it to the shop when service engine light came on..it came up mass air flow sensor...the car was running when i took it in!!..i had them clean mass air flow and put a new icm in it..now the shop cant get it started but a couple seconds then dies..they inform me there no fuel pressure..there not sure if its the fuel pump or some wiring issues but at 91 dollars an hr theyll try and find the problem..of course!!)..
I have replaced mass air flow sensor...mass air flow relay..icm unit..checked fuel pump fuse in fuse box...and the fuel pump is not even a year old..had battery checked they said it was bad but it still holds a charge..when i turn the key on the fuel pump only make a slight click sound....and they said all injectors are ok..What am i missing here !!..whats my next step..

 

I would think soon as they found problem with fuel pressure the next step they would have done was check power and any intermittent voltage issues at the pump. If your mechanic is correct that there is no pressure I can't believe he would not have provided you with the sequence of steps he would do to narrow problem down. Is the "mechanic" from Jiffy Lube??

 

No not jiffy lube....he checked nothing else out...but would for 91 dollars an hr...not trusting him i had my car towed out of the place...the fuel pump was working when i took the car there...

 

Whats my next step to my problem...thanks

 

Since you don't trust the mechanic my 1st step would be to check for proper pressure to see if indeed that is the problem. If it does start, even if just for seconds, fuel is there, but maybe to low to sustain it running. Until you do that basic step you won't know the next logical step. Lot's of smart members here that will happily help long as you have basic information for them.

 

When you say to low to sustain fuel..fuel pressure?
Also do u have any idea why my car would just die but then just start after it sat awhile..i know it resets the comp..but why would it die in the first place...

 

Do you have a good Fuel Pressure tester handy? First make sure that you have a good battery. Does it stay at 12.2 Volts or above when just sitting in the car off with nothing "on" inside the car. When was the last time the terminals were cleaned and wire-brushed? Batteries need yearly maintenance at least. It is important to have a healthy battery while diagnosing the systems of the 1988.

Once you have the battery system checked out then you install the fuel pressure gauge on the little valve on the passengers side fuel rail near the distributor. When you start a 1988 C4 Corvette you turn the key to run you should hear the fuel pump cycles on pressurizing the fuel loop so it is ready to start when the engine is turned over. You mention this fuel pump running earlier so it might be okay. How long is the fuel pump running for as it sits today? When not holding pressure the run time can be longer. Check the pressure gauge while the car is idling, a 1988 should be sitting around 42 pounds pressure (PSI). If you have the necessary pressure try starting the car and watching the gauge, it should stay in the same range while the car is idling.

I have a 1988 Corvette as well and I do know that the fuel pump relay can cause problems. Most of my fuel problems had electrical causes that kept them from working like they were designed to. Having a set of the factory manuals is a must for owning a car like this one.

You need to provide more information. Mileage on car, auto versus manual and what was replaced and when (in the past couple years only please). My 1988 C4 Coupe had all kinds of electrical issues pop up after the car sat a couple years. I had to clean the primary power connections supplying power to the dashboard and the rest of the car, then my fuses would not flow current so I had to fix that issue. The fuel pump problems I had were caused by a internally plugged fuel supply line to start with and bad wiring by previous owner. Check the wires that are connected to your distributor as sometimes the power wire there breaks and makes intermittent contact, there is a reason they put a clip to lock this wire on. Mine was broken and I also had a bad wiring connection at the oil pressure sensor, if the computer does not see oil pressure it won't activate the ignition (at least on the 1988 C4's).

Is the battery better than just okay?
How much pressure does your fuel pump develop?
Are you getting any OBD1 Codes or have a reader/scanner that can read them? There is a way using a paper clip for those brave enough
Do you have the Factory Service Manual for this particular car's year?
When was the last time the car worked normally?
Does this car have the factory VATS (Vehicle Anti-Theft System) system still in it?
You can activate the fuel pump manually by putting power into the correct wires of three wire harness that connects the fuel pump and the fuel level sensor and is located under the gas cap/fuel filler plate.
Something as simple as a bad ground strap can cause havoc in a C4. I had a bad ground strap that kept my power antenna from rising to the occasion when the radio was turned on.

Good Luck and don't give up quite yet!

 

Car ran like a top...1988 auto 102.000...2 months ago i started having trouble...
1st time..My car staled but then started after a minute..
Second time ..weeks later it started i put it in drive it staled..waited a few minutes it started..
3 rd time driving down road it just died..i unhooked the batt..hooked right back up it started..i go on line ask questions: so i replaced mass air flow sensor...mass relay...icm unit..the fuel pump is only about a year old..
I drove my car to the shop it was running great..i get mass air flow sensor cleaned..icm..oil change..they go to start the car it wont start..i told them to unhook batt and rest comp as i did.didnt work..they tell me im not getting pressure..how did my fuel pump or whatever go bad with the car sitting in the shop for a day..i also had the car takin to another shop when it died on me..they sprayed starting fluid in it...wont start...they go out the next day the car starts right up...

 

Start simple, they tell you it not get fuel pressure, you tell they to replace fuel filter, then tell they to recheck pressure.

 

I took both these hoses off..turned car over no gas comes out...bad fuel pump?

..or should i check some fuses some where first...thanks

 

Hello ,
I don't know if someone has mentioned has mentioned this. The oil pressure sender unit. If it thinks your oil pressure is low, below 4 psi, it will shut the car. My friend brought his car to a performance shop they did the heads car was running great and would just stop. Oil pressure sender was bad. Just a thought. Good luck.

 

Not true. Lack of oil pressure will not shut the car down unless the motor seizes. I would try to put the old ecm back and try a restart.

 

You are WRONG!!! /WRONG!!! And I will tell you why.
I owned a 1984 Corvette On that car the oil pressure shut off was set to 10 psi. How do I know this because when ever my oil pressure read 9 psi the car would stall.
I took the car to a track and the oil heated up to 240 degrees. I installed an external oil cooler. A line came off the oil cooler and the engine SHUT OFF.
I had work done on my 1989 and the mechanic mention.ed to me that the car had a 5 psi minimum. If it got below 5 psi the car would shut off fuel pump
My friend with his 2002, also a C4
In a thread posted by LUCKY 131969 in -19-2009, 06:52 PM He mentions how the C4 had oil pressure shut offs at 5 psi. In the 1985 FSM [age E63-85 4 PSI So the C4 will shut off when it thinks it has low oil pressureIn the FSM the oil pressure gauge is in the same wiring that the fuel pump is. So guess what I am right. On the C4 fuel pressure shuts off when oil pressure goes below a certain valueOH and in the FSM the oil pressure gauge is in line #2 l

 

Perhaps you should read this article on engine start sequence published by Grumpy's Performance. Note the third paragraph regarding Initial Crank Action.

http://www.corvetteactioncenter.com/...uence-802.html

 

Hello 383vette,

I do know these facts.
The car is designed so that the fuel pump will run for two seconds after the key is turned on.
Once the car is running oil pressure goes up, over 5 psi and the car continues to run.
If the oil pressure goes below 5 psi the car shuts down.
In 1984 the minimum pressure was 10 psi.

And the link you sent me seems to support me. The C4 , 1985 until ?, Corvette requires 4 psi of oil pressure to run the fuel pump.

 

jseremba - I meant that link for all. It was not directed at you.

 

I think that is a myth. My car started with 0 psi reported oil pressure. I disconnected the sender. It is a BACKUP circuit.

 

With the oil pressure sensor disconnected, it will BOTH run and start on my 91. Don't know about 84.

On page 6E3-A-2 of my FSM, under NOT ECM CONNECTED, it lists N7 as the Oil Pressure sensor (gage) and switch (fuel pump) connected. On page 6E3-A-12, it isn't listed on the Tech 1 Data which means it isn't monitored by the Tech 1 or the ECM so regardless of what the ECM "thinks" the pressure is, it isn't going to be a scan concern. That leaves the "off on" status where it either is enough pressure or not. On 6E3-A-66, it shows it as ONE OF THE TWO things that feed the line to the fuel pump. So it is a backup circuit.

Even on Grumpy's page, it shows that it is a backup circuit for a 90-92


Here it is for an 87 that I can't verify.

 

The diagram from the 88 FSM definitely shows that there are only two ways to get power to the fuel pump fuse. See the attached diagram out of the 88 Electrical FSM.
1. If power is supplied during start only through the fuel pump relay or
2. When the oil pressure switch is closed with normal oil pressure.

 

I see oil Pump and B2 of the ECM.