98fourunner

Hi everyone,

New user here.. I've used some of the threads on this board to try and figure out what could be the issue with my 98 4runner, with no luck so far. The car has just a bit over 200k miles on it with decent maintenance.

The issue I'm experiencing is starting on cold mornings (cold being in 30-45 degree range). The car will crank, start, and immediately die down. When trying again, same things happens - unless I keep the revs up at about 2k RPM for a minute and release the gas pedal. After a minute of revving, the tach needle drops down to 800 RPM and the car idles normally. Later on in the day it will start fine and the issue is much less pronounced.

I've cleaned the MAF sensor, cleaned the throttle body and IAC Valve (which was filthy), and replaced the fuel filter. None of those seem to have helped. Any idea on what might be causing this and what to look into next?

Thanks!

wyoming9

iTrader: (1)

Is the Mil on??

You should be getting a PO505 code

Have you checked your IAC was working when you had it off to clean??

Clean the connector when you had them off??

Did not bend any pins plugging things back in??

98fourunner

Checked for codes yesterday and got P0100 and P0110.

I did not check to see if it was working.. thread did not mention it, and I didn't realize. What's the best way to check?

I assume you mean the IAC valve connector under the throttle body? Did not clean that.


Fairly certain I did not bend any pins when plugging back in.
Also, the issue was happening before I cleaned the MAF, IAC, and replaced fuel filter.

Appreciate your help!

Riverman

I have the same problem with my '96 2.7 Tacoma. Although with mine, it's hard to start it again if I let it die when I first fire it up.

Like you, I cleaned the MAF, IAC, and throttle body. I also tested the IAC, and tested and adjusted the TPS.

I would love to hear some ideas from other folks.


I have read a few threads where people had a similar problem due to a rubber fuel line in the gas tank corroding over time from sitting in gas with ethanol. This makes it hard for the fuel pressure to build when you first start it, especially if the fuel has had a long time to drain back down out of the system. Not sure if that's true or not, but I've been too lazy to drop my tank and check. I've also read conflicting reports of whether this system is supposed to hold pressure, or if the pressure always dies off over the course of a few hours. Either way, I could see a bad fuel intake line causing the system to be slow to build pressure, and that could cause it to be hard to start.

Good luck figuring out what's wrong with your truck. Let me know what you learn!

nothingbetter

what about your cold start injector?

wyoming9

iTrader: (1)

well The P0110 is the coolant temp sensor circuit if this is not working the ecm can`t send the proper signal to the IAC

So the Engine starts hard compared to when things work correct

The PO100 is the Mass air flow circuit not always the sensor but they do fail I have changed a few in my day since having these 3.4 engines

With any of these problems worse case is that the ECM has failed.

It is great to have the diagnostics section in the Factory Service Manual for these things.