1G !STUMPED! Engine keeps flooding!

[90_GSX_DSM]

Alright guys I have a 1990 GSX that keeps flooding itself on start-up. If I let the car sit overnight and try to start it, it will start RIGHT up. If I turn it off and try to start it right back up it will spit and sputter like it wants to start and then just crank. Any attempt after this it will just turn over with no spits or sputters. While it's turning over ALL you can smell is raw fuel.

I had this problem when I first got the car running about a month ago but my gas light was on, I filled it up and it started every time. I thought this time it was the same thing so I went to the gas pump shut off the car and filled up. It didn't start back up. I got someone to tow it back to my work and have been diagnosing ever since.

One fix I found to get it to start every time is to disconnect the fuel pump, crank it until it fires up, and then plug the pump back in. But when I do this and give it any gas it falls on it's face and turns off.

Here is a relevant mods list: Wally 255, FIC750cc's, 3g MAF, 90 Eprom w/ Jeff O stage 3 chip, Aeromotive AFPR set to 37 psi at idle, 16g on 15psi, upgraded fuel feed line to 3/8, and new OEM fuel filter.

Here is a list of everything I replaced back to stock to narrow down the problem: ECU, MAF, injectors, EFI relay, FPR, and plugs.(I put all of this back in when nothing changed)

I'm honestly stumped right now. There are a few more things that I can think of, possibly timing, possibly not getting big enough spark to ignite the fuel(weak coil pack), bad o2 sensor, or bad cold start sensor? Anybody have any better ideas, or any ideas at all please don't hesitate to chime in. I just got this build done and I hate just seeing her sit. I am going to post two video's in a bit.

 

[92AWDHX40]

MMM sounds like a coolant temp sensor.

 

[90_GSX_DSM]

MMM sounds like a coolant temp sensor.

Sounds like a possibility. This is located on the thermostat housing?

 

[TurboTerror99]

Close, it's underneath the t-stat housing. I just changed mine and it cost me about $63.00 from the stealership. If memory serves me correct it's a two wire. The part number is MD069879. This one feeds the computer and would fool the computer into staying in "cold mode." Good luck.

 

[90_GSX_DSM]

Close, it's underneath the t-stat housing. I just changed mine and it cost me about $63.00 from the stealership. If memory serves me correct it's a two wire. The part number is MD069879. This one feeds the computer and would fool the computer into staying in "cold mode." Good luck.

Thanks for the information! Can I get a pic of exactly which sensor it is??

Well I'm going to try the coolant temp sensor to the ecu tomorrow if I can get a hold of the part tomorrow. If that don't work I'll try the coil pack. I'll let you guys know the outcome. Thanks for the help so far!!

MMM sounds like a coolant temp sensor.

Thank you my man!!! This ended up being the problem. She starts and runs like a champ now!!

 

[Geier]

Your basic logger would have solved the problem in 5mins. Get some basic logging software, so you don't have this problem next time!