88 lx 5.0 needs help!

[pearce9906]

I have an 88 lx 5.0 hatchback, 5 speed tranny. Stock except for bbk shortie headers, bbk cold air intake, accell ignition and wires.
Two days ago the stock fuel pressure regulator blew, started pumping gas through the vacuum port, straight into the plenum. Motor flooded out and died instantly, since then I replaced the bad reg with oem part, turns out it was a new BAD part, put another one on today, it works fine, but now I have a dead miss, sounds like at least two cylinders are dead, no knocking, no rattling. Doesn't sound like a bent pushrod, changed plugs before I put the first replacement reg on, haven't pulled the plugs back out after the second new reg was put on though. Any thoughts would be great.
If you need more info about the car just ask, I will tell all I can, only had it about a month, not sure about much history with it, but I will share all i can.

[DaLe five OH!]

change all the plugs out again

[Dark_5.0]

Yeah change the plugs again. If that doesnt work check the temp of the header tubes to find a potentially dead cylinder.

[pearce9906]

Thanks for the direction guys. I work tonight so I'll try swapping out the plugs first thing in the morning.
By the way, do you think it's possible fuel would have gotten into the sensors through the vacuum lines and ruined them? like the MAP sensor and the rest that have vacuum lines attached?

Thanks again, I'll let you know what I come up with.

[Dark_5.0]

Originally Posted by pearce9906

Thanks for the direction guys. I work tonight so I'll try swapping out the plugs first thing in the morning.
By the way, do you think it's possible fuel would have gotten into the sensors through the vacuum lines and ruined them? like the MAP sensor and the rest that have vacuum lines attached?

Thanks again, I'll let you know what I come up with.

I hydrolocked my 300zx last summer and it kept fouling the plugs cause water was pooled in the intake manifold. I removed all the spark plugs and jacked the car up on one side high as it would go to make all the pooled water run out of the intake and into the cylinders, then I turned it over in 20 second burst a few times and that seemed to work pretty well. All the water shotout the spark plug holes.

[pearce9906]

This one was hydrolocked also, after the original regulator blew, before I changed plugs, when I took the old (original) plugs out, I turned it over in several short bursts and blew the fuel out of the cylinders, it was fuel. Yours was water?

[Dark_5.0]

Originally Posted by pearce9906

This one was hydrolocked also, after the original regulator blew, before I changed plugs, when I took the old (original) plugs out, I turned it over in several short bursts and blew the fuel out of the cylinders, it was fuel. Yours was water?

Yeah I drove through some deep water and well you know the rest.

[pearce9906]

Well, I changed plugs out again, to no avail. EGR was bad, replaced it, as well as TPS, still not fixed. Noticed there were two vacuum solenoids on the right front inner fender on the the rear of the engine compartment that were damp with some gas, presumably from where the reg went bad and flooded the plenum and vacuum lines, I took them apart and cleaned them, that seemed to do the trick with getting the car running right and taking out the majority of the miss. But now I have severe idle surge, almost dropping to the point of killing itself, also running super rich. I've tried almost everything I can think of to narrow the problem down, but am having a heck of a time with it. Any ideas?
Keep in mind, I have just bought this car and don't have much idea about what mods previous owners have done to tune the car.

[bailey_57]

did you replace the tps and set it? surging idle is a problem as old as the 5.0. if you go through a search for surging idle you probably will find quite a few threads. also before i had any mods, i had a surging idle and chased all the gremlins. i got rid of mine with a 1/8th in drill bit through the throttle blade. good luck.

[pearce9906]

thanks for the reply baily_57, tomorrow is my day off so I plan to work on the car all day, hopefully I can chase my demon down, plan on setting the tps voltage, checking fuel pressure, checking compression, and possibly trying the codes, not throwing a check engine light tho, could mean the previous owner installed a chip or removed the bulb tho. Hopefully something will turn up tomorrow though, I am about at wit's end on this problem. Getting super frustrated. I'll post what I find. Thanks again.

[USMC302]

Might be a good idea to throw in some new o2 sensors.

[pearce9906]

Haven't checked the TPS voltage yet, but bought a code reader today, turns out I had a few codes, IAC valve, coolant sensor, which was my fault because I unplugged them whileengine was running, but also the fuel pump relay circuit was bad, pump is running all the time, which to my thinking would explain the rich condition and also the idle surge, if the motor is loading up with fuel at idle it would pretty much be flooding itself out. Correct? Also, the fuel pressure regulator is bad once again, I guess the pump running all the time is just building up too much pressure in the line and the diaphram in the reg is blowing out.

[USMC302]

It's supposed to run all the time when the engine is running.. What makes you say the FPR is bad again? You need to set the TPS, before we try to point fingers at anything else....

[pearce9906]

ECM says relay is bad. Trouble code 87. Also, even with the relay removed, fuel pump still runs when ignition is turned on, TPS voltage is now set at .96. Car runs, but still surging after about 3 minutes, also, fuel injecters are getting wet with fuel, on the outside. Not a leak on the fuel rail, it is a mist/smoke coming from around the injectors at about five minutes idle time, after the motor starts loading up with fuel.

Any idea why the fuel pump would run all the time (without the relay)?

[USMC302]

two things......The pump should NOT run with the relay out. Your referring to the relay under the seat right? That is the fuel relay.

Second, if you see fuel mist from the injectors, something is def wrong. I would pull the injectors and get them tested or serviced, where on the injector is the fuel mist coming from, can you see it exactly?