No Start & Big Backfire....Help?

[fivestardsm]

This might help..

 

[Kenny_Kline]

Have you checked what I told you to check yet?

hmmmmm.....

 

Yes, I completely checked all the wiring for the MAF, MAFT, & the SAFC wiring at the computer. No, I do not have a logger, but according to the SAFC the KAR values range in the 25-32 Hz area while the engine is cranking. It's not zero like yours was, but I don't know if the numbers I am seeing are correct. I will check the CASs again to make sure they are installed correctly, when you guys say "clean" them what do you mean? I cleaned the outside up, are you talking about cleaning the inside in some way?

 

[Nabeel]

I am having issue like yours at my VR4. Find a logger..You will save more time. I already order a new coolant sensor. Logger show engine temperture of 20-. And that makes the engine runing very rich.

 

[spoulson]

I've had similar symptoms just recently after it sitting for a couple months after finally replacing a dead battery. It started right up, but ran rough and lopey, probably on 2 or 3 cylinders. While it ran, I pulled each plug wire and each were arcing away. I then started pulling fuel injector plugs and found one that caused no change to idle. At first, I thought "oh great, ECU damage killed an injector driver". But strange, though unlike yours, by the time it warmed up the faulty injector fixed itself and it's been running great since.

If this doesn't sound like you, then I vouch for coolant temp sensor and/or wiring. To avoid confusion, there are three temp sensors on the thermo housing. The important one is the two-prong sensor on the underside. The top one is for A/C, and the single prong one is for instrument cluster. I had faulty wiring and caused similar extreme rich conditions so bad that attempts to accelerate actually lose power.

 

So here's an update on the car. I have been super swamped lately so the car has been sitting once again for the better part of a week. So I thought I would try & start it the other day just for giggles & it actually fired & ran for just a few moments. It ran pretty rough & blew all kinds of dark smoke out the exhaust that just smelled like super rich. I tried to keep it running by feeding some throttle, but it just died. Hasn't started since. Coughs once in a while but just cranks & cranks. I know its just super rich, it's just a matter of figuring out what is causing it.

Thanks Shawn for the insight. For whatever reason, when I read other posts about the coolant temp sensor failing, I was under the impression that it was the sensor on top of the thermostat housing. I now see the ones underneath I will replace the 2-prong one tomorrow & replace the wiring (it's very brittle & cracked). I completely re-wired & replaced the one on top thinking that HAD to be my problem, but when that didn't fix it I just about gave up. I'll let you guys know what happens after I replce the "correct" sensor /ubbthreads/images/graemlins/grin.gif

 

sounds like the coolant temp sensor is bad.. try pulling the fuel pump fuse and starting the car on carb cleaner.. the fuel pressure regulator could be bad

 

[1990ggsxnj]

I sure hope that's your problem, man. Fingers crossed.

 

OK, bought a brand new temp sensor...the 2-prong one on the underside of the thermostat housing... & installed it along with re-wiring the connector using a plug from the rear speakers. Still no start! /ubbthreads/images/graemlins/banghead.gif I also disconnected the fuel pump, sparayed starting fluid in each cylinder, got a couple coughs & sputters, but still no start. I took off the CAS & checked the alignment as per the diagram & it was fine. Someone mentioned the FPR, I'm not sure how to check that. My lines, rail & FPR are completely stock & have never been changed. There is no question I am getting fuel...every time I take a plug out it is soaked with fuel. So the question is, is it too much fuel, or a spark issue? I think my next step is to replace the ECU just to make sure. I pulled it out & visually inspected it, no signs of leakage or smell. As I posted earlier, it's a rebuilt E-prom. But when my original ECU failed a couple years ago the symptoms were exactly the same as they are now. I just need to find someone hopefully close by with a good ECU I can swap in. Otherwise I'm not sure what else to do..... /ubbthreads/images/graemlins/confused.gif

 

[Kenny_Kline]

Disconnect fuel pump power, pull sprak plugs, crank motor with plugs out of car, watch the gas fly out.

Chances are it gas washed. Get all the gas out by cranking motor and then reinstall plugs. Try again. WHile your doing this, get an injector pulse tester. Install on one injector and see how its pulsing. If it stays bright and doesnt flash during crank you have hung injectors (unlikely) or a bad ECU. If the light pulses, its not your ECU

 

[1990ggsxnj]

I would be careful if you've been fueling up that long. If you're washing the engine, you're taking oil away from all of that metal on metal. Few sprays of oil I'm sure wouldn't hurt either.

Curious, did you try disconnecting the maf to see if it will start in open loop?

 

get a vacuum pump attach it to the vacuum port on the fuel pressure regulator, pump it up to about 18. then try starting it after you have cleared the gas from each cylinder and put about a teaspoon of fresh oil in each

 

Mark, do give Knowles a call. I'm sure he'd be happy to let you borrow his ECU for a while; he mostly drives his trucks around during the winter.

Otherwise, you can borrow mine if you are coming through Modesto anytime soon, although mine hasn't run since 2004 and is a big unknown variable...

Good luck!
Dave

 

Well, I have been extremely busy lately so I have not been on here in a couple weeks. So...update on the car; The good news is that IT RUNS!!! It is finally ALIVE!! I did end up borrowing an ECU, & although that ended up not being the problem it eliminated one more possibility. As of right now, I don't know exactly what caused the problem, but the problem was just WAAAAYYY too much fuel. There was basically puddles of fuel in each cylinder. I finally got most of it out (not an easy process like you would think), dried the plugs numerous times, & it finally fired & ran. However, every time I gave it some throttle, it would load up & want to die. As long as I kept my foot off it ran OK, but had a lope to it & the A/F was below 11 at idle. I played with the AFC quite a bit & actually got it running pretty well...it was just soooo fat! Anyway, I am yet to road test it, but in the past week or so I have gone out & started it cold a couple times & it fires right off. It seems to run strong & I can go full throttle to redline if I want with no cutting out (like before).

Thats the good news....however, I do have some bad news....for me anyway. I know I had mentioned on here how I was planning to autocross this thing this year....well, plans have changed. I found a Miata that I just could not pass up, so I have decided to run that car this year & offer the Galant back up for sale. I don't want to do this, but I will be moving to the Bay Area in a few months & won't have the space for 2 race cars. It was a tough decision, but in the end the amount of money it would take to get the GVR4 competitive....& the fact that it would become a trailered race car that would not be driven on the street....all gave way to a super reliable stock class R package Miata that could be driven anytime. Anyway, if anyone is interested in the car I am going to post it in the for sale section. Thanks so much for all the advice on getting this thing running again, this forum has been a huge assett....not sure what I would have done without it!

 

I am going thru sort of the same thing. What did you end up with as far as settings on your SAFC? Mine is way rich at idle and slightly beyond. I have a palm coming so that I can datalog, just want to get it where I can go for a quick spin until it arrives. Thanks