Troy68

Ugh, I know! Not another one...

I feel like I've read every one of these threads 100 times already and I still can't sort out the problems with this truck! I was so happy to have gotten another Toyota pickup but this one is seriously making me reconsider my opinions. It's a 1993 Extended cab 4x4 with the 3.0 V6, manual transmission and has just over 135k miles. The previous owner was a college kid with no mechanical skills and had someone else do any work to it. The engine was supposedly rebuilt (family friend?) but wasn't running right. For the condition of the body/frame and the price I got it for I wasn't too concerned with the engine as my original plan was to drive it through the winter and then possibly try a V8 swap next spring. I really just want it to be reliable during the bad weather until I can spend more time going through it.

Initially it was hard to start but seemed to have good power once it got going - definitely more than any of the 4 cylinder trucks that I test drove. There was a strong smell of fuel and it would motorboat/surge when sitting at a light. I couldn't see a fuel leak and, after much research, thought it may be the regulator. While pulling apart the intake I noticed the front fuel line leaking so I tightened that and the fuel smell was gone. Easy fix! I traced the surging to the TPS and, after some trial and error, got the idle problem solved (new TPS "just in case"). Once I got those items fixed I reset the timing and idle speed according to the FSM. While cleaning the throttle body I noticed the intake hose was cracked and leaking so I replaced it. Gas mileage isn't stellar of course but I hear that's common. There's a pretty substantial oil leak coming from passenger side in the back and it may also have an exhaust leak. Hard to tell as this thing sounds louder than any of the other trucks I've owned.

When cold, it still takes several tries to get it started. Spins over fine and it will generally feel like it wants to start a few times and then nothing. After a couple minutes it will usually come to life but it shudders and complains for a bit before it settles down. I can generally smell fuel after a few tries and I can hear the fuel pump if I jumper the terminals (B+ and FP).

One day we were expecting snow so I took it around the block (about 5 miles) to make sure it was up to the task. Temp was about 30 degrees and it had rained for a couple days prior. I let it warm up for about 10 minutes and hopped in. Had the lights and heater going. About 2 miles down the road I turned onto a side street and it just died. I tried for about 10 minutes to get it going again but it wouldn't keep running (it would "catch" once in a while). I walked home (not fun!) and hooked up my trailer to my "big truck" and went to retrieve it. It was about 2 hours later when I got there and - just out of curiosity - I tried the key. It started after a few seconds. I towed it back to my garage any way. I messed with it for a few days and couldn't repeat the problem - it always started within a few tries. I checked for codes and didn't find any.

Fast forward to last week... Temp was in the mid-30s with a light rain. I took the truck down the road to pick up a movie (lights and heater on). When I came out of the store it wouldn't start. I called to get a ride home and went back the next evening with some jumper cables and a jumper wire for the diagnostic port. Again, I checked for codes and didn't find any. Hooked up the cables and it fired right up so I headed for home. About 2 miles into the trip I came to a stoplight and it stalled. Same as before, it wouldn't start again - however, this time the battery seemed pretty dead but I was watching the gauges pretty closely during the trip and it seemed to be charging. I ended up having it towed home and that's where it sits now. I still haven't been able to get it to start again even after charging it all night.

I mentioned the rain because I had read in one of these threads where a guy said his truck leaked on the passenger side and had gotten water in the wiring connectors around the ECU which caused an intermittent start. I have checked for water in that area though and that doesn't seem like the case here. I will be having the battery checked as soon as I get a chance - although I suspect it needs replacing after the way it acted last time. Perhaps that is causing issues with the ECU and sensors? If so, that's probably not the sole issue I'm dealing with. I have read that the crank position sensor could cause the hard starting problems. I don't know if that would also cause the rough idle once it starts though. The truck seems to run fine once it's warm (other than the stalling naturally).

I really don't want to throw a bunch of money at sensors/repairs since I've pretty much decided that I don't like this engine any way. I have access to a 3.4 with reasonably low miles so I may attempt that swap in the spring (if I'm feeling adventurous I have a Ford 351W and a few small block Dodges in my garage). The battery is something that I expect to replace no matter what. However, I still need the truck to be somewhat reliable until then. I don't like getting stranded in the middle of winter!

I suspect the wiring may have issues and, judging from the previous mechanic's shoddy work, there may be some loose connections as well. I'm stumped - but with my limited knowledge I'm not really surprised.

Troy

ksti

Put in a new battery and then lets see what happens.

yotaman85

it sounds like you have a couple wires loose. check the grounds from motor to body and from the fuse box to body. and obviously the power wires from battery.

Troy68

Thanks.

I picked up a new battery and will install it tonight when I get home. I doubt that is the complete problem though. Thinking back, the two times it stalled I was on a slight incline - but it was in a flat parking lot when I couldn't get it restarted and I live in a hilly area (with my driveway being one of the steepest). I've poked and prodded most of the wires to see if I can generate a miss or stall. I think I'll check the electrical components to see if any are getting hot. It's snowy and miserable out today so I'm not sure how long I want to stand out there and be frustrated. If it were throwing a code at least I'd have a more defined place to start.

Troy

Troy68

Installed the new battery and it started - although it took several tries as usual. Once I got it going I could shut it off and it would fire right back up. There are no codes at all. I put a voltmeter on it and it showed a steady 13.5 volts at idle. I believe that's low(?). I didn't think about it last night but I should check that with the lights on and heater blasting. Both times it has stalled on me was coming to a stop (clutch in, engine at idle) with a heavy electrical load. However, I wouldn't think a temporary drain like that would keep it from restarting. I wiggled and pulled every wire in the engine compartment with no ill effects. I shut off all the lights to see if there were any visible shorts as well. Since this is exactly how it has acted before I really don't feel confident with driving it.

Troy

ladybugRC

Hey Troy-
This may not be your problem at all, but I'll throw it out there just in case:
I was having very similar problems with my '87 4runner (22RE). It would start fine one day, I'd drive it to the store a mile or two down the street, get back in and it would crank and crank- sometimes it would start and sometimes I'd have to walk home. It was getting spark and when it did start it usually ran fine- though it did die on me a couple of times, just as you described. My intial thought was the ECU- some sensor was wigging out, giving the wrong mix or something, making it really hard to start, etc... I also noticed that the rain seemed to make it worse... then the cold, then the warm- after a while I realized there really was no rhyme or reason to when (or if) it would start... to make a (very) long story short- it ended up that my fuel pump was on the fritz. I replaced the pump and it has started instantly every time. I only mention it because most people I talked to told me a fuel pump basically either works or it doesn't- in my case, anyway, that wasn't true. I know you said you could hear it, but I could too. I guess maybe they're not as simple as we might like to think.
Just my thoughts!
Good luck!
Joe

Troy68

Thanks. All but 2 of my cars are older than me so they're much easier to troubleshoot (fuel - air - spark)! It really does feel like a fuel problem. I don't have the correct gauge to test it - but I can get one easily enough. In the old cars with mechanical pumps they'll usually start once there's enough gas to spin the engine a bit faster (faster pump operation = more fuel). On this truck things are intermittent. After cranking for a few seconds it will sometimes speed up until it's just stumbling along. Sometimes it will get better and sometimes it will stall out again. If it stays running it generally fixes itself within 10-15 seconds. That leads me to believe it's not electrical. I tried jumping the fuel pump terminals in the diagnostic box (to force the pump on) and it still wouldn't start. When it won't start at all I can usually smell fuel so that makes me lean towards ignition issues. Is it possible that there's too much fuel and it's flooding it out? Maybe. I will have to pull a couple plugs next time. It does not make it any better or worse if I push the throttle.

I read on here somewhere about attaching a test light to the fuel pump circuit.

Something I just remembered... when it was leaking at the fuel rail it was a constant drip. How much pressure is in those lines?

Troy

ladybugRC

Man, I know somewhere on here one day I read about fuel pressure at start and at idle and different RPMs... but I cannot find it... and I don't know what it should be.
I did come across this though, seems to have helped some folks, at least you could rule out the fuel pump:
http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump
I might just think its a fuel thing because that's what mine was- and it seems to me that fuel problems are easier for me to get my head around than all the electronic stuff... I hear you on the older trucks being easier to troubleshoot...
Again, good luck!
Joe

Troy68

That link is incorrect but I was able to find the page. Here it is in case anyone else is reading:
http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

That should be very helpful!

Also, this appears to be the thing I was thinking of with regards to water leaking on the passenger side dash:
http://www.4crawler.com/4x4/CheapTri...ORelayLocation

Troy

ladybugRC

Oops... I thought I could just copy that link-- I'm still very new at this...
Beyond the basics, I'm afraid I just might not be any help. I'm only familiar with the problems that I've had with my own vehicles over the years. So far, this old 4Runner has been challenging me the most! I'll let you know if I come across any other information that might help.
Joe

sixstringslut

When my 22R had problems starting in he rainy/damp days it tuned out to be plug wires, though don't remember it stalling out.

You could still be having pump problems even if it tests good. Maybe the wires to the tank or ground could be effected by moisture?

You were thinking of putting a perm/temp test light on pump circuit? Tape it to the dash until you get this ironed out.

Troy68

My truck never starts easily - although, it does generally start on rainy days. The two times it has stalled and stranded me have been cold/damp.

I will pull the plug wires and check the resistance over the weekend. I almost always do a complete tune-up whenever I buy a car but I haven't on the last two. OE parts for these Toyotas are expensive - and generally hold up well - so I don't tend to replace anything without knowing it's bad.

My gut feeling on the starting problem is that the fuel is draining back to the tank when it sits. Since the pump doesn't prime or even activate until cranking it may take some time to get fuel to the injectors. If the AFM(?) valve isn't working perfectly then maybe it's cycling the pump which causes it to take even longer. However, in real life that doesn't seem to be the case because I can hotwire the pump and it still takes a lot of work to get it started. But that's what it feels like any way. If I can set up a test light and/or gauge I'll probably run it that way for a while.

It rained all day yesterday and the truck started last night. I wasn't brave enough to take it for a ride. I should probably go through all the grounds just to rule them out.

Troy

sb5walker

I very much agree with those pointing to fuel. Not because it is likely the only problem (it isn't) but because the gas smell points without a doubt to a fuel leak. And there are MANY sources of ignition on a motor vehicle. This is not a criticism in any way, just an educated guess, but you have never witnessed a fuel-fed vehicle fire, have you? Any of us who have would never - and I mean never - drive a vehicle with a fuel leak. You don't mention having checked the most common spot for leaks on this motor:
https://www.yotatech.com/forums/f116.../#post51836582

But since the motor was rebuilt, perhaps incompetently, it's also possible for any of the fuel line fittings to have leaks. As you pointed out, any leak that lets fuel out will also let air in after you shut it off (if the check valve in the pump is leaky - which at this age it probably is) - and that will allow air to be drawn into the upper fuel lines as the fuel drains back into the tank. So when you first start, it takes a while for the fuel to make it back up to the injectors, and by that time the cold start injector is no longer firing (usually fires in the range of 3-8 seconds) so if it's cold it may not want to start.

So first order of business - FIND AND FIX THAT FUEL LEAK! Then, if it still has problems, let us know what's happening and we can try to help.

Troy68

It *was* leaking at the fuel rail under the intake where it couldn't be seen - and it never hit the ground which was why it was so hard to find. I fixed that and checked thoroughly for other leaks without finding any. I did check the FPR (1st post, 3rd paragraph but I just said "regulator") which is why I was taking the intake off when I found the leak at the rail. I thought (at the time) that the leak was lowering the pressure at the injectors which was causing the slow starting - but it still acts the same.

The fuel smell now is, I believe, coming from the exhaust after cranking and cranking with no fire. It's bound to blow unburnt fuel out after a while. It's not nearly as strong or long lasting as when it had a leak and I can't smell it in the cab - only when I get out of the truck (my exhaust has been routed out the driver's side for some reason). I get the same on my carbureted cars if I disconnect the coil wire (or when the ignition points are fried). I've had plenty of fuel leaks with those (although at much lower pressure) so I know the difference. However, I will check everything again to be sure. It's back up in the 50s and sunny today so it won't be so terrible to be crawling around on/in it.

I wasn't aware that the cold start injector had a timer. That explains a lot. I doubt if it's ever started within 10 seconds when cold. It has surged a little but not kept running.

I have no idea why the engine was pulled/rebuilt in the first place. Possibly because it ran like garbage? It doesn't seem like the rebuild helped which may be why it was for sale. The fuel leak, air leak, and busted/misaligned TPS definitely didn't help! So, perhaps there are long-standing issues that may have been made worse by pulling the engine. I still think there's an exhaust leak but the engine is so loud I'm having trouble pinpointing it. I've heard these manifolds have a habit of cracking.

Troy

sb5walker

How's your cat after cranking when it's not starting? Usually if there's a lot of unburnt fuel going out the exhaust the cat will get hot - in some cases cherry red - and there's a strong rotten egg smell. If not, then perhaps fuel isn't getting into the cyls, and a fuel pressure test might be needed.

If fuel checks out, you might try using the "test mode" to look for short-lived codes. It's explained in the Diagnostics chapter:
http://www.ncttora.com/fsm/1993/engine/85diagnosi.pdf

Note that with normal mode diagnostics, you turn ignition on then jump TE1 to E1. In test mode, you have to make sure TE2 is jumped to E1 before turning ignition on, then try to start the motor and if it starts, drive around for a bit at over 6 mph, then with motor still running, add a second paperclip to jump TE1 to E1, leaving the TE2 jumper in place. Then count your CEL flashes. If the motor won't start, it will still work, but you'll get starter signal and vehicle speed sensor codes (42 & 43) which can be disregarded. If you have an auto tranny, you may also get 51 as a spurious code.

Troy68

Ok, still stumped. However, I decided to test the voltage with everything on (heater blasting, headlights, and brake lights) at idle. I turned the key to run and listened for noises. I didn't hear the fuel pump or any relays. I tried starting the truck and could hear clicking from the area of the ECU and relays. It took about four tries to get going and I let it warm up completely. I attached the voltmeter to the battery and it was reading 13.6 volts steady. While in the engine compartment I bumped the throttle while watching the meter and when I let off it stalled. This time I could hear the pump still running. It restarted on the first try but only held a stumbling idle. Tapping the throttle made it stall again. The fuel pump was still running. I restarted again and this time the idle smoothed out. I was still able to get it to stall by blipping the throttle. I cannot see any fuel leaking nor can I smell any.

So why is the fuel pump staying on? If it's the AFM then why doesn't it come on when first turning the key? Why does the engine stall when letting off the throttle rapidly? I know there is a solenoid or something to "cushion" the linkage when it returns to idle but it appears to be adjusted correctly. Even if this is working why did it idle weird when restarted?

Thanks,
Troy

bookenns

Reading your thread reminded me of what I went through with mine when I did the head gaskets. When hooking everything back up, I failed to insert the push-on connector to the back of the alternator. It looked like it was on, I got 13+ Volts when I checked, but it would idle low and stall sometimes. I didn't have the start issues you seem to be having but I had replaced my battery with an upgraded one. I am not saying that this is the fix, but I know I've been caught before with simple stuff. Just look down your alternator and check that connector is in snug. When my kid (embarassing) found mine and pushed it in, the problems went away.

Troy68

That would be so awesome if it were the fix! Can't hurt to try any way. The alternator acting up could have killed the previous battery which *can* cause some of the weird starting/stalling due to low voltage in the electronics.

Troy

AlfaMessi

Hello Troy,
Any info what was the fix of this issue? My 93 Toyota pick up also act similar as yours and it’s a major headache thanks in advance.

Troy68

Ummmm, no. I ended up doing a 3.4 swap and sticking the 3.0 in my 95 4Runner that threw a rod out the side of the block. Both ran great! I learned a LOT about fuel and wiring during the swap and I'm wondering if I may have had a loose ground (back of the head?). These vehicles do lots of weird things when there isn't consistent voltage.

Troy